The Guideline for Processing Flexible Endoscopes has been approved by the AORN Guidelines Advisory Board. It was presented as a proposed guideline for comments by members and others. The guideline is effective February 1, 2016. The recommendations in the guideline are intended to be achievable and represent what is believed to be an optimal level of practice. Policies and procedures will reflect variations in practice settings and/or clinical situations that determine the degree to which the guideline can be implemented. AORN recognizes the many diverse settings in which perioperative nurses practice; therefore, this guideline is adaptable to all areas where operative or other invasive procedures may be performed.
This document provides guidance to perioperative, endoscopy, and sterile processing personnel for processing all types of reusable flexible endoscopes and accessories. Recommendations are provided for design and construction of the endoscopy suite as well as for controlling and maintaining the environment to support processing activities. Guidance is provided for maintaining records of processing for traceability and for quality assurance measures related to processing flexible endoscopes and accessories.
Patients have a right to undergo endoscopic procedures in a safe, clean environment where personnel adhere to consistent, evidence-based practices for processing every flexible endoscope every time care is provided. It is essential that the risk of patient-to-patient transmission of infection via flexible endoscopes be minimized as much as is reasonably possible.
Infections related to endoscopy procedures may be caused by endogenous microorganisms that colonize the mucosal surfaces of the gastrointestinal or respiratory tract and gain access to the bloodstream or other sterile tissues as a consequence of the procedure.1 Endogenous infections include infections such as cholangitis that may occur after endoscopic procedures of the biliary tract or pneumonia that may occur after endoscopic procedures of the respiratory tract.1
Infections related to endoscopy procedures may also be caused by exogenous microorganisms that are transmitted from previous patients or from the inanimate environment by contaminated endoscopes or accessories.1 The US Food and Drug Administration (FDA) has identified two recurrent themes as contributing to persistent bronchoscope contamination and transmission of exogenous infection:
a failure to meticulously follow the manufacturer’s written instructions for processing and
the continued use of bronchoscopes despite issues with integrity, maintenance, and mechanical problems.2
If flexible endoscopes are not correctly processed, exposure to body fluids and tissue remnants from previous patients may result in the transmission of pathogens to large numbers of subsequent patients.3 In a systematic search of the literature to clarify the epidemiology of Klebsiella species in endoscopy-associated outbreaks, Gastmeier and Vonberg4 found that insufficient processing was the main reason for subsequent pathogen transmission. The authors concluded that strict adherence to guidelines for processing flexible endoscopes in combination with alertness to the potential for pathogen transmission after endoscopy procedures was required, and that additional studies were needed to determine the true risk of pathogen transmission via flexible endoscopes.
Because of the many different types of flexible endoscopes and the differences in flexible endoscope construction, not all steps discussed in this guideline (eg, leak testing) will apply to all endoscopes; however, some steps (eg, manual cleaning) will apply to all flexible endoscopes. The European Society of Gastrointestinal Endoscopy (ESGE) has proposed a classification of endoscope families5 based on similar characteristics, including the number, construction, and purpose of the different endoscope channels and their clinical applications.
Group 1 endoscopes are typically intended for use in the gastrointestinal tract. This group includes endoscopes that have air/water channels, have an instrument/suction channel, and may have an additional instrument or waterjet channel. Examples of Group 1 endoscopes are gastroscopes, colonoscopes, and duodenoscopes with an encapsulated elevator channel.
Group 2 endoscopes are also intended for use in the gastrointestinal tract. This group includes endoscopes that have air/water channels, have an instrument/suction channel, and may have an additional instrument channel. Group 2 endoscopes also may have an elevator channel and up to two control channels for balloon functions. Examples of Group 2 endoscopes are duodenoscopes with an open elevator channel, echoendoscopes used for endoscopic ultrasound, and enteroscopes.
Group 3 endoscopes are used in bronchoscopy, otorhinolaryngology applications, gynecology, and urology. This group includes endoscopes with only one channel system for biopsy, irrigation, and suction or endoscopes without any channel. Examples of Group 3 endoscopes are bronchoscopes, cystoscopes, laryngoscopes, and nasendoscopes.
In addition to following the guidance provided in this document, it is critically important for individuals who are responsible for processing Group 1, 2, or 3 flexible endoscopes to follow the manufacturer’s instructions for use (IFU), and the IFU for all products and equipment used for processing flexible endoscopes. Processing flexible endoscopes is a complex cycle of multiple steps that includes point-of-use precleaning, transporting, leak testing, cleaning, inspecting, high-level disinfection (HLD) or liquid chemical sterilization, packaging and sterilization, storage, and use (Figure 1).
The complex design of flexible endoscopes increases the efficiency and effectiveness of endoscopic procedures; however, it creates enormous challenges for effective processing.3 Some parts of the endoscope may be difficult or impossible to access, and effective cleaning of all areas of flexible duodenoscopes may not be possible.6
Although single-use devices may meet the quality of reusable endoscopic devices and may provide an option for reducing the risk for transmission of infection,7–10 a discussion of the potential benefits of single-use flexible endoscopes is outside the scope of this guideline. The use of airborne, contact, or droplet precautions, the various chemicals used as high-level disinfectants or liquid chemical sterilants, the methods used for HLD or low-temperature sterilization, the methods for determining water quality used for processing flexible endoscopes and accessories, the protocols for microbiological surveillance of flexible endoscopes, the management of processing failures, sharps and medication safety, and the ergonomic injuries associated with the endoscopy environment are also outside of the scope of this guideline.
A full discussion of the design and construction of endoscopy suites in hospitals and outpatient facilities, the design of ventilation systems for controlling personnel exposure limits to chemicals used in the endoscopy suite, and the performance and use requirements for eyewash and shower equipment are outside of the scope of this document. However, because the design of the endoscopy suite and the procedures performed in the facility affect the processing of flexible endoscopes, some recommendations have been provided relative to procedure rooms and other elements of the endoscopy suite.
A medical librarian conducted a systematic search of the databases Ovid MEDLINE®, EBSCO CINAHL®, and Scopus® as well as of the Ovid Cochrane Database of Systematic Reviews. Search results were limited to literature published in English from 1994 through 2014. At the time of the initial search, the librarian established weekly alerts on the search topics and until October 2015, presented relevant results to the lead author. The author and the librarian also identified relevant guidelines and guidance from government agencies, professional organizations, and standards-setting bodies. Finally, during the development of this guideline, the author requested supplementary searches for topics not included in the original search as well as articles and other sources that were discovered during the evidence-appraisal process.
Search terms included the subject headings endoscopes, disinfection, decontamination, sterilization, disinfectants, detergents, biofilms, infection control, cross-infection, equipment contamination, occupational exposure, protective clothing, and hypersensitivity. Subject headings and key words for specific types of endoscopes, bacteria, disinfectants, and protective devices also were included, as were headings and terms related to the concepts of endoscope storage, methods of reprocessing, disinfection monitoring, infection transmission, disposable and reusable equipment, occupational allergies and injuries, and air pollution and ventilation. Complete search strategies are available upon request.
Excluded were non-peer-reviewed or retracted publications and evidence specific to the mechanism of action or health hazards associated with specific high-level disinfectants or liquid chemical sterilants, rigid endoscopic instrumentation, endoscopic medical treatment protocols, techniques, patient management, or functional design of flexible endoscopes.
In total, 1,257 research and non-research sources of evidence were identified for possible inclusion, and of these, 418 were cited in the guidance document (Figure 2).
Articles identified by the search were provided to the lead author and an evidence appraiser. The lead author and evidence appraiser reviewed and critically appraised each article using the AORN Research or Non-Research Evidence Appraisal Tools as appropriate. The literature was independently evaluated and appraised according to the strength and quality of the evidence. Each article was then assigned an appraisal score. The appraisal score is noted in brackets after each reference, as applicable.
The collective evidence supporting each intervention within a specific recommendation was summarized and the AORN Evidence Rating Model was used to rate the strength of the evidence. Factors considered in the review of the collective evidence were the quality of the evidence, the quantity of similar evidence on a given topic, and the consistency of evidence supporting a recommendation. The evidence rating is noted in brackets after each intervention.
Note: The evidence summary table is available at http://www.aorn.org/evidencetables/.
Editor’s note: MEDLINE is a registered trademark of the US National Library of Medicine’s Medical Literature Analysis and Retrieval System, Bethesda, MD. CINAHL, Cumulative Index to Nursing and Allied Health Literature, is a registered trademark of EBSCO Industries, Birmingham, AL. Scopus is a registered trademark of Elsevier B.V., Amsterdam, The Netherlands.
The endoscopy suite consists of a minimum of three functional areas: procedure room(s), processing room(s), and patient care area(s).11 The design of the endoscopy suite, and the procedures performed in the facility affect processing of flexible endoscopes.
The benefits are that construction and design to support processing activities may improve efficiency, help to reduce the risk of cross contamination, and provide a safe work environment. The reader should refer to the Facility Guidelines Institute (FGI) Guidelines for Design and Construction of Hospitals and Outpatient Facilities11 for additional guidance.
I.a. Except for precleaning processes performed at the point of use, endoscope processing should occur in a room where only processing activities are performed and that is physically separated from locations where patient care activities are performed.12,14,16–18,20–22 [1: Strong Evidence]
Limiting endoscope processing activities to designated processing rooms may help prevent contamination of procedure rooms and patient care areas.22
The minimum standard for design and construction of hospitals and outpatient care facilities is a single endoscopy processing room containing both decontamination and clean areas.23
I.b.1 During the infection control risk assessment, a multidisciplinary team that includes infection preventionists, endoscopy and perioperative RNs, sterile processing personnel, endoscopists, and other involved personnel should determine the potential harms compared with the benefits of performing decontamination and clean activities in separate rooms. [3: Moderate Evidence]
I.b.2. The endoscopy processing room should include a door11 that provides access to and from the decontamination area or decontamination room12 and a separate door that provides access to and from the clean area or clean workroom.25
Automatic sliding doors or foot-operated doors may be used.21
[2: High Evidence]
Doors to the decontamination area and clean area help contain contaminants within the processing room and help prevent cross contamination.25 Automatic sliding doors and foot-operated doors facilitate hands-free movement of flexible endoscopes and other items to and from the endoscopy processing room.
I.b.3. An endoscopy processing room with a one-room design should provide
[3: Moderate Evidence]
Cross contamination can result when soiled items are placed in close proximity to clean items or are placed on surfaces upon which clean items are later placed. Separation of the decontamination area from the clean area minimizes the potential for contamination of clean and processed flexible endoscopes.12,13,16,22,23,27
Hota et al28 demonstrated that contaminated water droplets had the ability to travel a distance of 39.4 inches (1 m). There is no evidence to indicate that contaminated water droplets from endoscope cleaning activities would be dispersed farther than 39.4 inches (1 m). It is unlikely that microorganisms would be disseminated by air over longer distances because they would be contained within water droplets.23
Separating soiled and clean work areas by a distance of at least 3 ft (0.9 m) aligns with current recommendations from the Centers for Disease Control and Prevention (CDC) that patients who require droplet precautions should be placed at least 3 ft from other patients.29
Having a wall or physical barrier for separation of the decontamination area provides protection and minimizes the potential for contamination of clean and processed flexible endoscopes.
I.c. The endoscopy processing room should be designed to facilitate a unidirectional workflow from the decontamination area or decontamination room to the clean area or clean workroom and then to clean storage in a separate location.1,11–15,17,18,20,25,30 [2: High Evidence]
I.d. Heating, ventilation, and air conditioning (HVAC) systems for the endoscopy suite should be designed in compliance with state and local building codes and other guidelines as set forth by the FGI and American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE).11,15,31 [4: Limited Evidence]
Heating, ventilation, and air conditioning systems control the air quality, temperature, humidity, and air pressure of the room in comparison to the surrounding areas.32 The HVAC system is intended to reduce the amount of environmental contaminants (eg, microbialladen skin squames, dust, lint) in the endoscopy suite.31,32
I.d.1. Heating, ventilation, and air conditioning systems in the endoscopy suite should be constructed and designed to meet the parameters shown in Table 1. [4: Limited Evidence]
The minimum HVAC values are for new construction or major renovations. They are not intended to be used as values for operating older facilities built when lesser standards were in place.
I.d.2. The minimum number of air changes in the endoscopy suite, including the percentage of outdoor air, should be maintained within the HVAC design parameters at the rate that was applicable at the time of design or of the most recent renovation of the HVAC system.32 [4: Limited Evidence]
Filtered air minimizes the recirculation of indoor contaminants within the area.32
I.d.3. The incoming air should be sequentially filtered through two filters. The first filter should be rated as 7 MERV (ie, minimum efficiency reporting value) and the second should be rated as 14 MERV.11,32 [4: Limited Evidence]
The incoming air requires continuous filtration because dust and airborne fungi are present at all times.32
Minimum efficiency reporting values measure the effectiveness of the air filters on a scale from 1 to 16.31 The higher the MERV rating on a filter, the fewer the dust particles and other contaminants that can pass through it.31
I.d.4. The airflow direction (ie, pressure relationship of one area to adjacent areas) for the endoscopy suite should be within the HVAC parameters.32 When endoscope processing activities will occur in two rooms, the pressure relationship should be
[4: Limited Evidence]
The direction of the airflow from one room to the adjacent area is engineered to minimize the flow of contaminants from dirty to clean areas.31 Negative pressure in the decontamination room helps prevent contaminants from flexible endoscopes and other items being processed from reaching surrounding environments.26 Positive pressure in the clean workroom helps prevent contaminants from surrounding environments from reaching the clean room.26
I.d.5. Bronchoscopy procedure rooms should be designed to be under negative pressure to the surrounding areas.11,32,35,36 For patients who require airborne precautions when a negative pressure room is not available, a portable, industrial grade high-efficiency particulate air (HEPA) filter or portable ante-room system (PAS)-HEPA combination unit may be used to supplement air cleaning.32,35 [1: Strong Evidence]
Use of an airborne infection isolation room; negative pressure room; or portable, industrial grade HEPA filter or PAS-HEPA combination unit helps prevent the spread of airborne pathogens, particularly tuberculosis, rubeola, and varicella zoster, and is recommended during procedures that can generate infectious aerosols (eg, bronchoscopy).29,36 The reader can refer to the Health-care Infection Control Practices Advisory Committee “Guideline for isolation precautions: preventing transmission of infectious agents in healthcare settings”29 and the AORN Guideline for Prevention of Transmissible Infections35 for additional guidance.
I.d.6. Ventilation within the endoscopy suite must be controlled to meet personnel limits for chemical exposure as required by local, state, and federal Occupational Safety and Health Administration (OSHA) regulations37,38 and should be accomplished in accordance with industry standards11,31 and professional guidelines.18,22,39–46 [1: Regulatory Requirement]
I.e. Structural surfaces (eg, doors, floors, walls, ceilings, cabinets, shelves, work surfaces), furniture (eg, tables), and equipment in the endoscopy processing room, procedure rooms, and patient care areas should be smooth and made of materials that are water resistant, stain resistant, and able to withstand frequent cleaning.11–13,21 [2: High Evidence]
Structural surfaces that are smooth and able to withstand frequent cleaning ease the cleaning process. A clean environment will reduce the number of microorganisms present.
I.e.1. Ceiling surfaces in the endoscopy processing room, procedure rooms, and patient care areas should not be composed of perforated, serrated, cut, or highly textured tiles.11 [4: Limited Evidence]
Perforated, serrated, cut, and highly textured ceiling tiles may create a reservoir for the collection of dirt and debris that cannot be removed during cleaning.
Providing tight seals and enclosing pipes and other fixtures above work areas helps prevent contamination from dust, condensation, and other potential sources of contamination.12
I.e.3. Floor surfaces in endoscopy processing rooms, procedure rooms, and patient care areas should be monolithic.11 Junctions between floors and walls should have an integral coved wall base that is carried up the wall a minimum of 6 inches (152 mm) and is tightly sealed to the wall.11,13 [4: Limited Evidence]
Seams, joints, or crevices may harbor microorganisms.12
I.e.4. The integrity of surfaces within the endoscopy suite should be maintained, and surfaces should be repaired when damaged.32 [2: High Evidence]
Damaged surfaces may shed particles into the environment12 and may create a reservoir for the collection of dirt and debris that cannot be removed during cleaning.32 Damage to floor surfaces may create a trip or fall hazard.32
I.f. Lighting in the endoscopy suite should be designed in compliance with state and local building codes and other guidelines as set forth by the Illuminating Engineering Society of North America.47 [4: Limited Evidence]
Well-designed lighting facilitates visual inspection of flexible endoscopes and other tasks performed in the endoscopy suite.
I.f.1. Lighting should be designed to provide good visibility for personnel to perform necessary tasks and should be adjustable.47 [4: Limited Evidence]
Although a very high illuminance capability may be required for some tasks, too much light can be uncomfortable. Adjustable lighting improves comfort by allowing personnel to increase or decrease the lighting level as needed to perform the task.47
I.g. Hand washing stations in the endoscopy suite must be readily accessible48 and should be provided in the decontamination room and the clean workroom.11,21 When endoscope processing activities will occur in a single room, a hand washing station should be provided in the decontamination area.11 [1: Regulatory Requirement]
Providing readily accessible hand washing stations is a regulatory requirement.48 Hand washing stations that are easy to access facilitate hand washing and may improve hand hygiene compliance.17 Hand hygiene is required after removal of personal protective equipment (PPE).35,48
○ When two decontamination sinks (or one sink with two divisions) are provided, one sink (or division) should be designated for leak testing and manual cleaning, and the other for rinsing.12
○ Three decontamination sinks (or one sink with three divisions) may be provided in the endoscopy processing room.12 When three decontamination sinks (or one sink with three divisions) are provided, one sink (or division) should be designated for leak testing, the second for manual cleaning, and the third for rinsing.12,13
[3: Moderate Evidence]
Sinks are required for functions such as leak testing, cleaning, and rinsing of flexible endoscopes and other items being processed. Separate sinks or divisions facilitate endoscope processing and may help prevent cross contamination.
Silva et al49 reported a pseudo-outbreak of Pseudomonas aeruginosa and Serratia marcescens involving 41 patients who underwent bronchoscopy procedures in a 380-bed private hospital in Sao Paulo, Brazil, between December 1994 and October 1996. As part of the investigation, the investigators reviewed and observed endoscopy processing procedures. They found that in addition to other inadequacies in the processing procedures, the same sink was used for both washing and rinsing the bronchoscopes. The pseudo-outbreak resolved with improved processing procedures that included separate sinks for washing and rinsing of the endoscopes.
I.h.1. Decontamination sinks should be deep enough to allow complete submersion of the endoscope and large enough to allow the endoscope to be positioned in the sink without tight coiling.12,13,15,22,25 [2: High Evidence]
Compressed air facilitates flushing and drying of channels and lumens.12 Clean, filtered air is required for drying lumens and small channels without introducing contaminants into the clean device.
I.j. Eyewash stations, either plumbed or self-contained, must be provided within the endoscopy suite where chemicals that are hazardous to the eyes are located.52 [1: Regulatory Requirement]
It is a regulatory requirement that emergency eyewash stations or showers be immediately accessible in locations where the eyes or body of any person may be exposed to injurious corrosive materials.52
Many chemicals are eye irritants. Eyewash stations are necessary to provide flushing fluid when the safety data sheet identifies the chemical as a hazard and recommends immediate flushing of the eyes as an emergency first aid measure.
I.j.1. Eyewash stations should be located
in a well-lit area identified with a highly visible sign positioned within the area served by the eyewash station,53
so that travel time is no greater than 10 seconds from the location of chemical use or storage,53 and
on the same level as the hazard, with the path of travel free of obstructions (eg, doors) that may inhibit immediate use of an eyewash station.53
[4: Limited Evidence]
I.j.2. Eyewash stations should be positioned with the flushing fluid nozzles not less than 33 inches (83.8 cm) and not more than 45 inches (114.3 cm) from the surface on which the person using the eyewash station stands and a minimum of 6 inches (15.2 cm) from the wall or the nearest obstruction.53 [4: Limited Evidence]
I.j.3. Eyewash stations should not be installed in a location that requires flushing of the eyes in the decontamination sink. [5: Benefits Balanced with Harms]
Splashing from the decontamination sink could potentially contaminate the eyes of personnel using the sink.
I.j.4. Once activated, eyewash stations should be capable of delivering tepid (60° F to 100° F [16° C to 38° C]) flushing fluid to both eyes simultaneously at not less than 0.4 gallons (1.5 L) per minute for 15 minutes at a velocity low enough to be noninjurious to the user and without requiring the use of the operator’s hands.53 [4: Limited Evidence]
The reader can refer to the current ANSI/International Safety Equipment Association (ISEA) American National Standard for Emergency Eyewash and Shower Equipment53 for additional guidance.
The collective evidence supports processing flexible endoscopes in an area where activities such as temperature, humidity, environmental cleaning, surgical attire, traffic patterns, and security are managed in accordance with specific policies and procedures that promote processing activities.1,11–19,24
The benefits are that this may improve efficiency, maintain functionality of flexible endoscopes and other medical devices, help to reduce the risk of cross contamination, and provide a safe work environment.
The limitations of the evidence are that no research studies have investigated the link between patient outcomes and flexible endoscopes processed in a controlled area.30
Monitoring performance of the HVAC systems helps ensure that the desired HVAC parameters are being achieved and maintained.
II.a.1. Relative humidity should be maintained within the HVAC design parameters for endoscopy suites.32 [4: Limited Evidence]
The effect of relative humidity on bacterial, fungal, and viral growth is inconclusive. Additional research is warranted to determine optimal relative humidity levels for control of environmental contamination.32
II.a.2. The room temperature in the endoscopy suite may be intentionally adjusted based on the needs of the patient and the comfort of personnel.32 [4: Limited Evidence]
Maintaining comfort and normothermia of patients in procedure rooms or patient care areas may require that room temperature be adjusted outside of the recommended range. Temperature settings in non-clinical areas may also need to be adjusted to provide comfortable temperatures for personnel based on the activities being performed (eg, a lower temperature may be required in the decontamination area where PPE may be worn for long periods of time).12
II.a.3. Personnel who identify an unintentional variance in the predetermined HVAC system parameters in the endoscopy suite should report the variance according to the health care organization’s policy and procedure.32 [5: Benefits Balanced with Harms]
Rapid communication between affected and responsible personnel can help facilitate resolution of the variance.32
II.a.4. Designated personnel from the health care organization should perform a risk assessment if a variance in the parameters of the HVAC system occurs.32 [5: Benefits Balanced with Harms]
The effect of the HVAC system parameters falling out of range is variable. A small variance for a short period of time may not be of clinical concern, whereas a large variance for a longer period may have clinical significance.32
II.a.5. Based on the risk assessment, corrective measures should be taken and may include
terminal cleaning of surfaces when there is evidence of contamination on surfaces;
reprocessing or discarding any supplies with packaging that may have been compromised;
inventorying discarded, damaged supplies to obtain replacements; and
modifying or updating the HVAC system.32
[5: Benefits Balanced with Harms]
II.b. Hand hygiene practices should be implemented in the endoscopy suite in accordance with the AORN Guideline for Hand Hygiene.54 [2: High Evidence]
Hand hygiene has been recognized as a primary method of decreasing health care-associated infections.54 Health care-associated infections can result in untoward outcomes such as escalated cost of care, increased rates of morbidity and mortality, and longer lengths of stay, as well as the pain and suffering a patient may experience.54
Because of a severe outbreak of Kelbsiella pneumoniae producing extended-spectrum beta (ß)-lactamase that occurred in 16 patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) procedures in a hospital in France between December 2008 and August 2009, Aumeran et al55 observed the duodenoscope processing procedures. They found a lack of personnel compliance with recommended hand hygiene practices, and they concluded that the hands of personnel may have been a source or vehicle for transmission of the outbreak strain.
Cleaning endoscopes in hand washing sinks could contaminate the sink, faucet, and hands of personnel subsequently washed in the same sink.12
II.b.2. Decontamination sinks should not be used for hand washing.12 [4: Limited Evidence]
Hand washing in the decontamination sinks could contaminate the endoscope or other items subsequently washed in the same sink.12
II.c. Processes and procedures for environmental cleaning in the endoscopy suite should be carried out in accordance with the AORN Guideline for Environmental Cleaning.56 [1: Strong Evidence]
A clean environment will minimize the exposure risk of health care personnel and patients to potentially infectious microorganisms.56
II.d. Clean surgical attire and head coverings should be worn in the processing room and procedure rooms of the endoscopy suite. [5: Benefits Balanced with Harms]
Surgical attire is worn to provide a high level of cleanliness and hygiene within the endoscopy environment and to promote patient and worker safety.57 Head coverings contain hair and minimize microbial dispersal.57
II.e. Personnel working in the endoscopy suite must wear PPE. [1: Regulatory Requirement]
It is a regulatory requirement that PPE be worn whenever splashes, spray, spatter, or droplets of blood, body fluids, or other potentially infectious materials may be generated and eye, nose, or mouth contamination can be reasonably anticipated.48 Employers are required to ensure that employees are protected when exposed to eye or face hazards from liquid chemicals.59
II.e.1. Personal protective equipment should be worn in accordance with the AORN Guideline for Prevention of Transmissible Infections,35 the AORN Guideline for Surgical Attire,57 and the AORN Guideline for Cleaning and Care of Surgical Instruments.58 [1: Strong Evidence]
II.e.2. Personnel working in the endoscopy processing room and handling contaminated flexible endoscopes should wear PPE that includes
surgical masks in combination with eye protection devices, such as goggles, glasses with solid side shields, or chinlength face shields;
general purpose utility gloves with cuffs that extend beyond the cuff of the gown; and
fluid-resistant shoe covers.
[1: Strong Evidence]
Contaminated flexible endoscopes are a potential source of transmissible pathogens.58 Personal protective equipment helps to protect processing and procedural personnel from exposure to blood, body fluids, and other potentially infectious materials.58
Surgical masks in combination with eye protection devices can protect the wearer’s face, eyes, nose, and mouth from exposure to hazardous chemicals as well as pathogenic microorganisms, body fluids, and other potentially infectious materials.57 The mucous membranes of the nose, mouth, and eyes may act as portals of entry to infectious agents.60 In addition to the risk for injury from a direct splash to the eye, there is also a risk of developing conjunctivitis or a systemic infection.60 Skin may also act as a portal when its integrity is compromised by trauma or disease.60
Kaye61 reported an unusual complication of inoculation in the eye by effluent from the open biopsy port of a flexible esophagoscope. The patient was diagnosed with herpetic esophagitis. After esophageal brushings and biopsies had been obtained, the endoscopist attempted air inflation and a jet of fluid was directed from the patient’s esophagus into the endoscopist’s right eye, which was immediately flushed with copious amounts of water. One week later, the endoscopist noted an itchy papule beneath the right eyelid that developed into multiple conjunctival vesicles. Conjunctival cultures were positive for Herpes simplex virus (HSV). The endoscopist subsequently developed a sore throat (also culture-positive for HSV), neck stiffness, lymphadenopathy, and splenomegaly that resolved within a week. The conjunctival HSV reappeared approximately two weeks later and resolved without further recurrence. The author concluded that although this was a rare event, it is conceivable that diseases such as tuberculosis and hepatitis could be transmitted in a similar way. The author recommended that endoscopists keep their faces away from the biopsy port and seal it as soon as the forceps have been withdrawn. In all likelihood, the splashing of fluid into the endoscopist’s eye would have been prevented by the use of protective eyewear.
Fluid-resistant gowns can prevent transfer of microorganisms from contaminated items to skin.58
General purpose utility gloves can minimize the potential for punctures, nicks, and cuts, and exposure of the hands and forearms to blood, body fluids, and other potentially infectious materials.58 Wearing utility gloves with cuffs that extend beyond the cuff of the gown helps provide protection from fluids during cleaning of flexible endoscopes and other items in the decontamination sink.58
Fluid-resistant shoe covers can protect shoes from splashes, splatters, and spills.58
II.e.3. Hand hygiene should be performed after removal of PPE.29 [1: Strong Evidence]
The CDC recommends performing hand hygiene after removal of PPE.29 Hands may become contaminated when removing PPE. Damage to PPE in the form of tears, punctures, and abrasions may occur and be undetected, exposing the wearer to microbial contamination and bloodborne pathogens.60
II.e.4. Reusable PPE must be decontaminated and the integrity of the PPE verified between uses.48 Reusable PPE must be discarded if there are signs of deterioration or its ability to function as a barrier has been compromised.48 [1: Regulatory Requirement]
Decontaminating reusable PPE and verifying its integrity between uses is a regulatory requirement.48 Reusable gloves, gowns, aprons, and protective eyewear or face shields may become contaminated and their integrity compromised during use.
II.f. Personnel working in the endoscopy suite should be immunized against vaccine-preventable diseases in accordance with the AORN Guideline for Prevention of Transmissible Infections.35 [1: Strong Evidence]
Personnel may come into contact with patients or infectious material from patients that may put them at risk for exposure and possible transmission of vaccine-preventable diseases.35
II.g. Traffic patterns within the endoscopy suite should facilitate movement of patients, personnel, equipment, and supplies into, through, and out of defined areas within the endoscopy suite. [5: Benefits Balanced with Harms]
Effective traffic patterns support safe patient care, workplace safety, and security.32
II.g.1. Processing room doors should be kept closed except during the entry and exit of personnel. [5: Benefits Balanced with Harms]
Keeping the doors closed helps prevent contaminated particles from entering or leaving the room and maintains the pressure differential required for decontamination rooms. Keeping the door closed also assists with venting contaminated room air out of the building, minimizing contamination of adjacent areas.32
II.h. Designated personnel from the health care organization, in consultation with security personnel or law enforcement representatives, should develop a security plan for the endoscopy suite.32 [5: Benefits Balanced with Harms]
Including the endoscopy suite in the facility-wide plan takes into consideration the unique security risks created by the presence of high-value equipment, medications, and supplies and the variable hours during which the suite may be unoccupied.32 Security personnel and law enforcement representatives have expertise in identifying security risks and in prevention and mitigation tactics.32
II.h.1. Security measures should be selected based on a risk assessment and may include the use of devices (eg, alarm systems, video surveillance, shatter-proof glass) or controls (eg, locked doors, tracking systems, visitor logs).32 [5: Benefits Balanced with Harms]
Security measures provide for the safety of patients, personnel, and visitors.32
II.i. Processes and procedures for purchasing, evaluating, and selecting flexible endoscopes, accessories, equipment, and other items and products related to the use and processing of flexible endoscopes should be carried out in accordance with the AORN Guideline for Product Selection.62 [2: High Evidence]
Patient and worker safety, quality, and cost containment are primary concerns of endoscopy personnel as they participate in evaluating and selecting medical devices and products for use in endoscopy settings.62
II.i.1. Endoscopes, accessories, and equipment used in the endoscopy suite should have manufacturer-validated IFU. [1: Strong Evidence]
Manufacturers of reusable devices cleared by the FDA provide validated cleaning and processing instructions and guidance on how to process devices between uses. Items cannot be assumed to be correctly processed unless the manufacturer’s IFU are derived from validation testing and the instructions have been followed.58
Validation by the manufacturer provides objective evidence that the requirements for the specific intended use of the product or device can be consistently fulfilled.63–65
II.i.2. Prepurchase evaluation of flexible endoscopes, accessories, and equipment should include
ensuring that the facility has the capability to comply with the manufacturer’s IFU,
confirming that the manufacturer’s IFU can be replicated, and
verifying compatibility with other relevant manufacturers’ IFU.
[5: Benefits Balanced with Harms]
Manufacturers’ IFU vary widely. Some devices or items may have unique requirements that may not be achievable within the facility.
II.i.3. Endoscope accessories and devices specified by the endoscope or mechanical processor manufacturer for cleaning and processing should be obtained at the time of endoscope purchase and used in accordance with the IFU.58 [1: Strong Evidence]
Using accessories and devices that are designed and manufactured to the endoscope or mechanical processor manufacturer’s specifications helps ensure the endoscope can be used effectively and facilitates performance of cleaning and processing procedures.58
II.j. Processes and procedures for managing new, loaned, and repaired endoscopes, accessories, and equipment in the endoscopy suite should be carried out in accordance with the AORN Guideline for Cleaning and Care of Surgical Instruments.58 [1: Strong Evidence]
Adhering to the AORN guideline will help ensure successful management of new, loaned, or repaired items.
II.k. Flexible endoscopes and endoscope accessories should be cleaned and processed by individuals who have received education and completed competency verification activities related to endoscope processing.15,66 [2: High Evidence]
The collective evidence shows that ensuring flexible endoscopes and endoscope accessories are processed by individuals whose primary duties are to clean and process flexible endoscopes minimizes variability and improves processing effectiveness.67,68 Having individuals who have received education and demonstrated competency process flexible endoscopes and accessories helps reduce the risk for errors and cross contamination.66,69 Individuals whose primary duties are to clean and process flexible endoscopes bring a specialized level of knowledge to the processing procedure that may include
○ an improved understanding of the health and safety issues that can arise when endoscopes are not correctly processed,69
○ an in-depth knowledge of the structure and operation of the endoscopes they are responsible for processing,69
○ an in-depth knowledge of the structure and operation of the mechanical processors they are using for processing,69 and
○ a desire for additional education related to processing of flexible endoscopes and accessories that may improve the quality and standard of processing.69
A dedicated team of individuals responsible for processing flexible endoscopes may also allow endoscopy nurses to focus on clinical responsibilities.69
Kolmos et al70 reported a pseudo-outbreak of P aeruginosa in eight consecutive HIV-infected patients undergoing bronchoscopy in Denmark. None of the patients developed signs of respiratory tract infection that could be ascribed to the organism. The investigators found the source to be P aeruginosa contamination in the suction channels of two bronchoscopes. Due to the lack of a dedicated processing person, the nurses, who were inexperienced with processing procedures for flexible bronchoscopes, were not manually cleaning the endoscopes. Further, the mechanical processor was not working correctly, so the bronchoscopes were being manually soaked in glutaraldehyde in a location other than the endoscopy processing room. Interviews with the nurses confirmed that the suction channels had not been cleaned for many weeks before the pseudo-outbreak. When the channels were inspected, there were deposits of organic material in both bronchoscopes. The contaminated bronchoscopes were effectively cleaned and processed, and this stopped the outbreak. The investigators recommended having dedicated personnel process flexible bronchoscopes.
Ensuring flexible endoscopes and endoscope accessories are processed by individuals whose primary duties are to clean and process flexible endoscopes may also reduce repair costs and extend the life of the endoscope.67,68
McGill et al71 conducted a nonexperimental study to ascertain the durability of flexible cystoscopes in relation to their use in the outpatient setting. The researchers prospectively investigated cystoscope processing and repair costs for six new cystoscopes from July 1, 2008, through August 31, 2009, and compared these data with retrospective data from the previous eight months. During the prospective study period, the flexible cystoscopes were only processed by urology nursing personnel skilled in processes for handling and maintaining flexible cystoscopes. The researchers found there was a 43.9% decrease in repair costs and mechanical failure when the nurses processed the endoscopes.
To investigate the causes and costs of flexible ureteroscope damage and to develop recommendations to limit damage, Sooriakumaran et al72 analyzed repair costs and damage to 35 ureteroscopes sent for repair during a one-year period. The researchers found that the majority (72%) of the damages occurred during the cleaning and processing phase rather than during procedural use. The researchers suggested that having a skilled, dedicated team clean and process the ureteroscopes could help prevent damage and reduce costs.
In an effort to reduce costs and damage to flexible ureteroscopes, Semins et al73 studied the effect and analyzed the cost per use of having dedicated urology personnel clean and process all ureteroscopes rather than the facility processing personnel who cleaned and processed all other facility items. Between April 2007 and March 2008, when the urology team processed the ureteroscopes, 11 ureteroscopes were processed 478 times. The average number of uses per ureteroscope before repair was necessary was 28.1. The average repair cost per use was $120.63 ($134.33 in 2015 US dollars). During the previous year, when the processing was performed by facility personnel, the average number of uses per ureteroscope before repair was necessary was only 10.8. The average repair cost per use was $418.19 ($465.69 in 2015 US dollars). The authors concluded that having a skilled and dedicated team process ureteroscopes was an effective measure to reduce repair costs and processing-related damage to flexible ureteroscopes.
McDougall et al74 conducted a quasi-experimental study to determine whether the technique used to clean flexible ureteroscopes or the number of persons handling the endoscope during the cleaning process influenced function or number of repairs. The researchers used a new, flexible ureteroscope for each of two 30-day study periods. During the first study period, the endoscope was leak tested, cleaned, and processed by the endourology support team. During the second study period, the endoscope was leak tested, cleaned, and processed by the surgeon. The researchers found that the function and durability of the endoscope was not affected by the technique used to clean it or the number of people involved in cleaning and processing the endoscope. The function and durability of the endoscope was found to be affected by the demands of the surgical procedure and the technique of the surgeon.
II.k.1. Processing of flexible endoscopes should be performed in the same manner in all processing locations. [3: Moderate Evidence]
Smith75 reported two cases of septicemia caused by P aeruginosa following ERCP procedures. The investigators found that the accessory instruments used through the endoscope were cleaned with chlorhexidine gluconate and soaked in glutaraldehyde for one hour. After soaking, they were rinsed with utility water, and the lumens of the endoscope were flushed using single-use syringes. The accessory instruments were then placed into their original shipping containers while still wet and were stored in a cupboard. The syringes were stored in a wet condition and reused. The investigators sampled the syringes and found them to be culture-positive for the same strain of P aeruginosa that was found in the septic patients. The bacteria had been introduced into the patients’ biliary tract on endoscopy instruments contaminated after disinfection by the syringes used for flushing the endoscope channels. The endoscopes were being processed at multiple sites, with processing personnel following different processing procedures at different sites.
In a case control study of an outbreak of multidrug-resistant P aeruginosa, Machida et al76 found a relationship between the infections and contaminated bronchoscopes. Between June and August 2007, isolates from five patients in the intensive care unit (ICU) and emergency department (ED) of a 1,076-bed university hospital were culture-positive for multidrug-resistant P aeruginosa. All of the patients had undergone bronchoscopy procedures in the ICU or ED. The organism was not found in any of the bronchoscopes in use at the hospital; however, the investigators found that the bronchoscopes used in the ICU and the ED were processed differently from other hospital endoscopes.
The researchers retrospectively reviewed medical records from 2006 and found 11 additional patients with multidrug-resistant P aeruginosa. The review showed that these patients also had bronchoscopy procedures in the ICU or ED. Processing procedures were reviewed and showed poor compliance with hospital procedures for processing the endoscopes. The manual cleaning step was often skipped when the endoscopes were processed in the ICU or ED. The outbreak ended when effective cleaning and high-level disinfecting processes were established in all processing areas.78
Time constraints and insufficient numbers of endoscope processing team members may create a disincentive for personnel to adhere to recommended cleaning and processing procedures.58
II.k.3. Endoscopy procedures should be scheduled to allow sufficient time for cleaning and processing of flexible endoscopes.78 [3: Moderate Evidence]
Time constraints may create a disincentive for personnel to adhere to recommended cleaning and processing procedures.58
II.k.5. A multidisciplinary team that includes endoscopy personnel, RNs from departments where bedside endoscopy procedures are performed, infection preventionists, risk managers, endoscopy processing personnel, endoscopists, and other involved personnel should establish policies and procedures requiring that flexible endoscopes used for procedures performed at the bedside or outside of normal operating hours are processed in the same manner as endoscopes used during normal operating hours. [3: Moderate Evidence]
Flexible endoscopes are complex and costly devices that require multiple processing steps. Having skilled, dedicated personnel process flexible endoscopes for emergency procedures performed outside of normal operating hours helps ensure that the endoscopes have been processed correctly and are safe to use.68
Bou et al79 conducted a cohort study to identify risk factors for infection following an outbreak of P aeruginosa infections in the 27-bed ICU of a community hospital in Spain during July 2003. The investigators identified 17 case patients with 25 P aeruginosa infections that included respiratory tract infections (n = 21), a bloodstream infection (n = 1), a urinary tract infection (n = 1), a pressure ulcer (n = 1), and a surgical site infection (n = 1). Ten of the 17 case patients had undergone bronchoscopy procedures in the ICU during a weekend. A review of the weekend processing procedures showed major deviations from hospital policies. Adequate cleaning and HLD were not performed. The weekend procedure involved rinsing the bronchoscope with povidone-iodine and placing the bronchoscope into its storage case without drying. The bronchoscope was then transported to the endoscopy unit where it was stored in a drawer until its next use. On weekdays, the bronchoscope was either manually or mechanically cleaned and high-level disinfected without a sterile water rinse, alcohol flush, or purging with air. Notably, the manufacturer’s IFU were not being followed in the ICU or the endoscopy unit. The researchers concluded that education of processing personnel was necessary to ensure processing was carried out in accordance with published guidelines in all areas of the hospital and during all hours processing procedures were performed.
Srinivasan et al80 conducted a survey among 46 practicing bronchoscopists to assess their knowledge of recommended guidelines and processing procedures. The survey was distributed to participants in two bronchoscopy courses attended by pulmonologists from the United States. The results of the survey showed that 65% of the bronchoscopists (n = 30) were not familiar with bronchoscope processing guidelines and 39% (n = 18) did not know what processing procedures were used in their own facilities.
To audit processing of flexible endoscopes used during procedures performed outside of normal operating hours, Radford et al81 conducted a telephone survey of 104 ear, nose, and throat units in England. On-call clinicians from 72 units (69%) agreed to participate. The researchers found that the on-call clinician processed the flexible endoscope in 60 units (83%); however, the on-call clinician had only received education and hands-on instruction on processing procedures in 27 units (38%). In addition, clinicians in 19 units (26%) followed inadequate processing procedures, and clinicians in 16 units (22%) were unsure of the correct processing method. In one case, the clinician admitted to not cleaning the endoscope between procedures. In 35 units (49%), the endoscope was stored in an unsterile carrying case. In seven units (10%), the on-call clinician did not know how the endoscope was stored. The researchers concluded there was an urgent need for compliance with effective processing procedures for flexible endoscopes used for emergent endoscopy procedures performed outside of normal operating hours.
Flexible endoscopes and accessories should be precleaned at the point of use.
The collective evidence supports precleaning of flexible endoscopes at the point of use as a mechanism for moistening, diluting, softening, and removing organic soils (eg, blood, feces, respiratory secretions) and reducing the formation of biofilm. If organic soil and biofilm are not removed completely, the subsequent HLD or sterilization process might not be effective.82 The need for precleaning at the point of use is emphasized in numerous clinical practice guidelines.12,13,15–22,27,44,45,83–85
The benefits of precleaning flexible endoscopes at the point of use are that it eases86 and improves87 the cleaning process and helps reduce the formation of biofilm, which can interfere with HLD or sterilization.82
III.a. Precleaning of flexible endoscopes and accessories at the point of use should occur as soon as possible after the endoscope is removed from the patient (or the procedure is completed) and before organic material has dried on the surface or in the channels of the endoscope.12,13,18–22,27,44,45,83–85,88 [1: Strong Evidence]
In a quasi-experimental laboratory study, Merritt et al86 evaluated the effects of 12 different cleaning solutions on four microorganisms known to adhere to polystyrene and medical implant materials (ie, Staphylococcus epidermidis, Candida albicans, Escherichia coli, P aeruginosa). The results of the study showed that allowing bioburden to dry on surfaces made cleaning very difficult. The researchers recommended that microorganisms, protein, or other materials not be allowed to dry on flexible endoscopes before cleaning.
Biofilm is difficult to remove and may begin to form within minutes after the procedure is completed.82,85 In an expert opinion article discussing biofilm development on the surfaces of medical devices and the role of biofilm in device processing, Roberts82 explained that the formation of biofilm begins when a layer of organic material is deposited on the surface of a medical device (Figure 4). Colonizing microorganisms subsequently become attached to this foundational layer. At this point, the microorganisms are loosely attached and can be removed by cleaning.91
Nearly irreversible attachment occurs as the microorganisms begin to multiply and form a mature biofilm.91,92 A mature biofilm consists of layers of bacterial cell clusters embedded in towers of polysaccharides secreted by the microorganisms into their environment.91–94 Microorganisms within a mature biofilm are protected by the secreted extracellular substances and may not be easily penetrated or killed by antibiotics, HLD, or sterilization.82,93–96 This protective mechanism may be related to physical, genetic, or physiological characteristics of the bacteria or their ability to produce neutralizing enzymes.45 The mature biofilm releases colonizing cells to form new biofilms on other surfaces of the device.82,94
Certain conditions are necessary for biofilm formation, including
○ the presence of colonizing microorganisms,
○ sufficient nutrients,
○ acceptable temperature conditions for growth, and
○ time required for the formation of biofilm.82
Some microorganisms undergo cell division every 20 to 30 minutes; however, it may take several hours for a mature biofilm to form.82 The time frame within which the cleaning of flexible endoscopes or other reusable medical devices occurs is therefore a key factor in the prevention of biofilm formation and buildup.82 Performing precleaning and the remaining processing steps within an hour after a procedure may prevent formation of a mature biofilm even under conditions favorable to rapid biofilm development.82
Biofilm can form on the inner surface of endoscope channels and is especially prone to form when these inner channels become scratched or damaged.93 Herrmann et al87 performed microscopic examinations of the inner surfaces of the suction and biopsy channels of new flexible endoscopes. They found that the channels were only partially smooth and contained small indentations and irregularities where biofilm could form and be retained even after cleaning. They noted that the formation of biofilm in the small indentations and irregularities was even more likely to occur if the endoscope was not cleaned immediately after use.
Effective precleaning processes may help to prevent patient infection. Naas et al97 reported an outbreak of carbapenemase-producing Klebsiella pneumoniae transmitted via a flexible endoscope. Retrospective analysis showed that 17 patients from five regional hospitals in France had undergone endoscopy with the same gastroscope. Of the 17 patients, six were colonized and two developed infections. A review of the endoscope processing procedures revealed that one potential explanation for the contamination was that the precleaning of the endoscope had been delayed for 24 hours, allowing organic material to dry on the device.
III.b. Precleaning should be performed in accordance with the endoscope manufacturer’s IFU. [5: Benefits Balanced with Harms]
There are multiple types of flexible endoscopes, and recommended precleaning processes may vary among manufacturers.
Variations from the manufacturer’s IFU may result in insufficient cleaning or in processing failure.
III.b.1. Steps for performing precleaning should include
[2: High Evidence]
Using a fresh solution for each new cleaning process may help prevent cross contamination of flexible endoscopes.98 Recommended cleaning solutions vary among endoscope manufacturers. Manufacturers have validated products with specific properties for effective cleaning of their devices.90
Washing the external surfaces of the endoscope and flushing the internal channels helps moisten, dilute, soften, and remove organic soils.
Suctioning all channels and cleaning the distal end assists with removing gross soil. Alternating cleaning solution with air may be more effective in loosening and removing organic soils. Finishing with air may help prevent excess fluid from remaining in the channels.13
Visually inspecting the endoscope after precleaning helps detect obvious damage to the endoscope.
III.c. When the precleaning process will be delayed (eg, an endoscope is used for intubation and remains in the procedure room for potential reuse), designated personnel (eg, RN circulator, scrub person) should wipe the external surfaces with a soft, lint-free cloth or sponge saturated with utility or sterile water and suction water through the channels.85 [3: Moderate Evidence]
Wiping the external surfaces and suctioning water through the channels of the endoscope may help prevent organic soils from drying, reducing bacterial adherence and the risk of biofilm formation until precleaning with a cleaning solution can be accomplished.
Microorganisms readily adhere to surfaces and begin forming biofilm.82 Biofilm that has formed in lumens is difficult to remove. If not removed, biofilm may reduce the efficacy of subsequent disinfection or sterilization.45
Shimono et al100 reported an outbreak of P aeruginosa infections that occurred following thoracic surgery in seven patients. The authors determined that one cause of the outbreak was dried organic material in the bronchoscope that occurred when the bronchoscope was reused several times during the surgeries without any cleaning or flushing between uses.
After precleaning at the point of use, contaminated flexible endoscopes and accessories should be transported to the endoscopy processing room.
The benefit of transporting flexible endoscopes to designated decontamination areas is that this may help prevent contamination of procedure rooms and patient care areas and also limits the number of areas where chemicals are used for cleaning and disinfection.22
IV.a. Contaminated flexible endoscopes and accessories should be transported to the endoscopy processing room as soon as possible after use. [3: Moderate Evidence]
Transporting the contaminated endoscope as soon as possible facilitates the ability to expeditiously initiate the cleaning process and helps prevent organic material from drying on the surface or in the lumens, which facilitates cleaning.69,86,87
IV.b. Endoscopes and accessories should be kept wet or damp but not submerged in liquid during transport. [2: High Evidence]
Keeping the endoscope and accessories wet helps dilute, soften, and ease removal of organic soils. Allowing organic material to dry on the surface and in the channels of the endoscope makes the cleaning process difficult.15,24,86
Submerging the endoscope in liquid during transport may increase the risk of spillage and could lead to fluid invasion if the endoscope has an unknown leak.
IV.c. Contaminated endoscopes and accessories must be transported to the decontamination area in a closed container or closed transport cart.48 The container or cart must be
[1: Regulatory Requirement]
Transporting items in leak-proof, puncture-resistant containers and in a manner that prevents exposing personnel to blood, body fluids, and other potentially infectious materials is a regulatory requirement.48
In a nonexperimental study to assess the costs of flexible ureterorenoscopy, Collins et al103 found there was significant damage to a new ureteroscope that produced a crescent-shaped defect in the field of vision after only 12 procedures. The defect was determined to be the result of coiling the ureteroscope too tightly in the cleaning tray.
IV.c.2. The transport cart or container must be labeled with a fluorescent orange or orangered label containing a biohazard legend (Figure 5).48 Biohazard labels must be securely affixed so as to prevent separation from the contents.48 [1: Regulatory Requirement]
Labeling containers of biohazardous material is a regulatory requirement48 and communicates to others that the contents may be biohazardous.
IV.c.3. Flexible endoscopes should be transported in a horizontal position and not suspended.102 [3: Moderate Evidence]
Fluid may leak from the contaminated endoscope if the endoscope is transported vertically. When suspended, the endoscope may become damaged because of compression on dependent components.102
Keeping the accessories with the endoscope helps prevent them from being lost or misplaced13 and supports traceability of the endoscope and accessories as a single unit. Placing the accessories in a separate container helps prevent damage to the endoscope and accessories.12,101,102
IV.d. Processing of endoscopes and endoscope accessories should begin as soon as possible after transport to the endoscopy processing room or within the manufacturer’s recommended time to processing. [3: Moderate Evidence]
IV.d.1. When it is not possible to initiate the cleaning process within the endoscope manufacturer’s recommended time to cleaning, the manufacturer’s IFU for delayed processing should be followed.12,16 [3: Moderate Evidence]
IV.d.2. Flexible endoscopes should not be left soaking in enzymatic cleaning solutions beyond the endoscope manufacturer’s designated contact time unless this is recommended in the manufacturer’s IFU for delayed processing. [3: Moderate Evidence]
Alfa and Howie104 demonstrated the ability of microorganisms to replicate in enzymatic cleaning solutions when held at room temperature (77° F [25° C]). Soaking endoscopes in enzymatic cleaning solutions beyond the manufacturer’s designated contact time may increase the potential for microbial contamination, biofilm formation, ineffective disinfection or sterilization, and moisture damage to the endoscope.99
IV.d.3. A procedure should be developed and implemented for recording the times that the procedure is completed and cleaning is initiated. [5: Benefits Balanced with Harms]
A process for recording the times that the procedure ended and cleaning was initiated enables processing personnel to ascertain how long the endoscope has been awaiting processing, to establish priority order, and to determine whether routine processing within the manufacturer’s recommended time to cleaning is achievable, and if not, to implement the manufacturer’s procedures for delayed processing.
IV.e. Transport carts or containers used for flexible endoscopes should be mechanically cleaned and thermally disinfected or manually cleaned and chemically disinfected with a compatible Environmental Protection Agency (EPA)-registered hospital-grade disinfectant after each use.69 [2: High Evidence]
Cleaning and disinfecting transport carts and containers after each use helps prevent cross contamination that could occur if clean items were placed on contaminated transport carts.69 Disinfectants that are incompatible with the cart or container surface may cause damage to the cart or container and may be ineffective when applied to the incompatible surface.
Flexible endoscopes designed to be leak tested, should be leak tested after each use, after any event that may have damaged the endoscope, and before use of a newly purchased, repaired, or loaned endoscope.
Not every endoscope requires leak testing.
Leak testing detects openings in the external surfaces and internal channels of the endoscope that could permit water, chemicals, or organic material to enter portions of the endoscope not intended for fluids.106 These materials may accumulate from the time the integrity of the endoscope is breached until the time the leak is identified. Leak testing may be accomplished by manual or mechanical methods and may be performed using a wet (ie, under water) or dry process.65
The benefits of leak testing are that it reduces damage and repair costs and decreases the potential for patient infection or injury that might result from use of an endoscope that is not completely sealed.85,89,107
Khan et al108 conducted a prospective quasi-experimental study to determine whether leak testing flexible ureteroscopes after ureterorenoscopy and laser fragmentation of renal calculi procedures reduced damage and repair costs. The new ureteroscope used for the Group 1 procedures (n = 95) was not leak tested after each procedure. The new ureteroscope used for the Group 2 procedures (n = 98) was leak tested after each procedure. Both groups were comparable for surgeon’s years of experience, stone location, size and number of stones, access sheath usage, and duration of lasering. During the study period, October 2010 to March 2011, there were seven repairs costing $46,264.40 in Group 1 ($49,322.39 in 2015 US dollars) and three repairs costing $9,952.80 in Group 2 ($10,610.66 in 2015 US dollars). The researchers concluded that leak testing of flexible ureteroscopes significantly reduced the costs of maintenance and repair by promoting early recognition of damage, allowing for earlier repair, and preventing further use of a damaged ureteroscope.
In an effort to determine the longevity of flexible ureteroscopes used in the urology department of a London hospital, Bultitude et al101 analyzed data for the number of procedures and repairs required for each of four new ureteroscopes used during 375 procedures. The results showed that on average, each ureteroscope was used 94 times, required two repairs, and was used for 36 procedures between each repair. To extend the life of the ureteroscope and help prevent unnecessary repairs, the authors recommended having dedicated personnel process the endoscopes, transporting endoscopes separately from the rest of the supplies and equipment, and performing a leak test after every procedure in order to detect and repair minor problems before they become major problems.
Leak testing may decrease the risk for an infection transmitted by a flexible endoscope. Ramsey et al109 reported an outbreak of Mycobacterium tuberculosis transmitted from a patient with active tuberculosis to at least two patients via a contaminated bronchoscope. Examination of the bronchoscope revealed a small leak in the external sheath of the bronchoscope tip. The hole had not been discovered previously because leak testing was not routinely performed after bronchoscope use. The hole allowed the M tuberculosis from the index case to be delivered directly to the distal airways of subsequent patients.
Cêtre et al110 identified 117 bronchoalveolar lavage samples contaminated with Enterobacteraceae during three consecutive outbreaks among 418 patients between March 2001 and October 2001 in a 700-bed hospital in France. The source of the contamination was found to be a loose port of the biopsy channel of two of the seven bronchoscopes used in the endoscopy suite. The bronchoscopes were subsequently recalled by the manufacturer due to a potential design flaw. The researchers speculated that leak testing performed after each procedure might have allowed for much earlier detection of the problem.
In a report that illustrates the importance of leak testing in preventing patient injury, Krishna et al111 described two cases of caustic mucosal injury of the larynx from exposure to glutaraldehyde retained in a damaged endoscope channel. The same laryngoscope was used for both patients. After examination, the laryngoscope was found to have retained glutaraldehyde because of an undetected perforation in the lining of the working channel. Both patients required inpatient admission with airway monitoring, and one patient required admission to the ICU. After treatment with antibiotics and steroids, the patients recovered with no further problems. The authors did not state whether leak testing was included in the processing of the laryngoscope in question; however, they concluded that leak testing was an important and necessary aspect of processing to determine whether the instrument channel had been damaged and to confirm the integrity of the laryngoscope.
Performing leak testing before cleaning verifies the integrity of the endoscope and helps prevent damage that might occur during the cleaning process if the endoscope has been compromised.
The addition of cleaning solution to the water used for leak testing may discolor the water or introduce bubbles, limiting the ability of the person performing the leak test to see the entire endoscope or bubbles from the endoscope that indicate leaks.16,107 Leaks may also go undetected because bubbles from leaks may be assumed to be bubbles from the cleaning solution.107
There are multiple types of endoscopes and leak-testing equipment. Steps to complete leak testing may vary among manufacturers.
V.b.1. Steps to perform leak testing should include
removing all port covers and function valves;
actuating video switches; and
maintaining pressure and inspection for a minimum of 30 seconds.12
[2: High Evidence]
Underpressurizing may allow a leak to go undiscovered; overpressurizing may stress seals and cause damage to the endoscope.107
Maintaining pressure and inspection for a minimum of 30 seconds may help reveal small leaks. Evidence for leak testing time is based on expert opinion. The AAMI12 recommends 30 seconds. Thomas107 recommended 90 seconds in order to help detect leaks that may not be detected immediately.
Removing the endoscope from service will prevent further damage to the endoscope84 and will prevent the damaged endoscope from being used.
After leak testing and before high-level disinfection or sterilization, flexible endoscopes should be manually cleaned.
The collective evidence indicates that cleaning is the most important step in the processing of flexible endoscopes.18,22,85,93,112–114 Because of the body cavities they enter, some flexible endoscopes acquire high levels of microbial contamination.45,112,113 Some flexible endoscopes contain multiple channels and ports that can easily collect organic material.45,93 The environment in which flexible endoscopes are used provides optimal conditions for contamination and growth of biofilm.93 When inadequately cleaned, contaminated endoscopes may be vectors of normal bacterial flora as well as pathogenic bacteria.115,116 When endoscopes are effectively cleaned, bioburden is reduced to a level that does not present a challenge to subsequent disinfection or sterilization.46,112,114,117
In a landmark study, Chu et al113 investigated and compared the bioburden levels on the exterior surfaces of the insertion tube and in the suction channels of colonoscopes immediately after use and after manual cleaning. The colonoscopes were collected from a free-standing endoscopy center and a hospital. Ten colonoscopes were sampled immediately after use, and 10 colonoscopes were sampled immediately after manual cleaning. The results of this randomized controlled trial showed that immediately after use, the level of bioburden on the exterior surfaces of the insertion tubes ranged from 1.2 × 104 to 1.5 × 106 colony forming units (CFU)/device. The level of bioburden in the suction channels ranged from 1.3 × 107 to 2.0 × 1010 CFU/device. After manual cleaning, the level of bioburden on the exterior surfaces of the insertion tube decreased to a range of 8.2 × 102 to 9.5 × 104 CFU/device, establishing that manual cleaning achieved a mean reduction of greater than 1 log. The level of bioburden in the suction channels decreased to a range of 1.3 × 103 to 4.3 × 105 CFU/device, establishing that manual cleaning achieved a mean reduction of 5.5 logs. The 4-log difference can be attributed to the fact that the suction channel is the working channel of the device through which suction occurs and accessories are inserted into the intended locations, so this lumen is exposed to a greater volume of intestinal material.
If endoscopes are not adequately cleaned, the disinfection or sterilization process can fail and increase the possibility for transmission of infectious microorganisms from one patient to another.112,114,116,117 Some disinfectants are inactivated in the presence of organic material.1,16
In a quasi-experimental laboratory study to demonstrate the effectiveness of a high-level disinfectant (ie, orthophalaldehyde), Alfa and Sitter115 sampled 10 bronchoscopes, 10 gastroscopes, and 10 colonoscopes immediately after use. They found the level of bioburden for the bronchoscopes was 6.4 × 105 CFU/mL−1, the level of bioburden for the gastroscopes was 1.7 × 105 CFU/mL−1, and the level of bioburden for the colonoscopes was 5.2 × 105 CFU/mL−1. The researchers noted that the average load of microorganisms was higher for the gastroscopes than for the bronchoscopes, reflecting the higher number of bacteria in the gastrointestinal tract compared with the respiratory tract, and was likewise higher for the colonoscopes than for the gastroscopes due to the higher concentration of microorganisms in the colon compared with the upper gastrointestinal tract or the bronchi. The endoscopes were cleaned and disinfected, and the residual microbial load was monitored by sampling the suction channels. The researchers found that the cleaning process alone removed up to 103 organisms, leaving fewer organisms for the disinfectant to kill. The cleaning and disinfection procedure achieved more than a 5-log10 reduction in bacterial load. The researchers emphasized the need to combine effective cleaning with the high-level disinfectant to ensure maximum efficacy of the disinfectant.
Cleaning is a process that uses friction, cleaning solution, and water to remove organic and inorganic debris to the extent necessary for further processing or for the intended use.12,58,89,93,112,117 Cleaning removes rather than kills microorganisms. The effectiveness of the cleaning process can vary based on a number of factors including the type of device being cleaned, the design of the device being cleaned, the person performing the cleaning, the amount of time spent cleaning, and the site where the device is cleaned.112 Routine cleaning procedures may not effectively remove biofilm from endoscope channels. Biofilm remaining in the lumen of an endoscope may prevent effective HLD or sterilization.92,115
In a quasi-experimental laboratory study, Pajkos et al92 assessed 13 biopsy channels and 12 air channels removed from 13 endoscopes that had been sent to an endoscope processing center in Sydney, Australia. The endoscopes were of various ages from 13 different hospitals, and no information was provided to the researchers as to the reason for servicing or how frequently the endoscopes had been used. The researchers used scanning electron microscopy (SEM) to examine the endoscope channels for the presence of biofilm. The SEM showed that biofilm was present on five of the 13 biopsy channels and on all 12 of the air channel samples. In addition, the researchers found surface defects that included cracks, grooves, and pits in many of the channels. The researchers concluded that cleaning had not removed all biofilm from any of the channels, and they noted that the presence of biofilm could lead to failure of the HLD process by inactivating or preventing penetration of the disinfectant.
Alfa and Howie104 investigated whether the repeated exposure to high levels of microorganisms and the wet and dry conditions that occur during the use and processing of flexible endoscopes could lead to an accumulation of organic material in endoscope channels, and whether this biofilm buildup presented a greater challenge to remove than traditional biofilm that forms when a surface is exposed to microorganisms and continually bathed in fluid. The results of the study showed that the biofilm buildup facilitated high levels of organism survival and reduced the efficacy of the two high-level disinfectants evaluated during the study (ie, glutaraldehyde, accelerated hydrogen peroxide). The researchers theorized that these results provided an explanation for the persistence of residual levels of biofilm remaining in endoscope channels even when the endoscopes were correctly processed. As flexible endoscopes are repeatedly used and processed, the load of bioburden increases, reducing the efficacy of the high-level disinfectant and increasing the risk for pathogen transmission.
The benefits of manual cleaning are that it removes visible soil and reduces the amount of microbial contamination and biofilm formation on and in the endoscope.16,83,84 If microbial contamination and biofilm are not removed completely, the surface under the bioburden may not be disinfected or sterilized.16,22,83,84,104,112,114,116 Manual cleaning helps ensure effective HLD or sterilization and may protect the patient from exposure to contaminated endoscopes that could result in transmissible infections.114,118
VI.a. Manual cleaning should occur as soon as possible after leak testing. [3: Moderate Evidence]
Initiating the cleaning process as soon as possible after leak testing helps prevent the formation of biofilm.82,83 Biofilm is difficult to remove and may begin to form within minutes after the procedure is completed.82 If biofilm is present on or in the endoscope, the subsequent HLD or sterilization process may not be effective.82,95,96
VI.b. Manual cleaning should be performed in accordance with the endoscope manufacturer’s IFU. [3: Moderate Evidence]
There are multiple types of endoscopes. Steps to complete cleaning may vary among manufacturers. Adherence to the manufacturer’s IFU may minimize the risk for infection.6
VI.c. Manual cleaning should be performed using the type of water recommended by the endoscope manufacturer. [4: Limited Evidence]
Recommendations for the type of water to be used for manual cleaning may vary among endoscope manufacturers. Utility water is often adequate for precleaning, manual cleaning, and rinsing; however, water quality is affected by the presence of dissolved minerals, solids, chlorides, and other impurities and by its acidity and alkalinity.119 The pH level of the water affects the performance of cleaning solutions.119 Untreated water quality fluctuates over time, varies with geographic location and season, and can affect the outcome of cleaning actions.119
VI.d. Manual cleaning should be performed using a cleaning solution recommended by the endoscope manufacturer. [2: High Evidence]
There are multiple types of endoscopes. Recommended cleaning solutions may vary among manufacturers. Following the endoscope manufacturer’s IFU decreases the possibility of selecting and using cleaning solutions that may damage the endoscope.
The chemical actions of cleaning solutions vary and are intended for different applications. The pH and rinsability of cleaning products also vary. Some cleaning solutions target specific types of bioburden (eg, protein, lipids); others are intended for general purpose cleaning.90 General purpose cleaners function primarily as surfactants.65,120
Enzymatic cleaners contain one or a combination of enzymes to help break down organic material and facilitate its removal.65,90,120,121 Enzymes are specific in terms of the soils they remove. Protease enzymes target proteins.120,121 Amylase enzymes target carbohydrates, starches, and sugars.90,120–122 Lipase enzymes break down fats and oils.90,120–122 Cellulase enzymes break down cellulose.90 Enzymatic cleaners attempt to remove biofilm by decomposing the extracellular polysaccharides surrounding and protecting the embedded microorganism.95 Because the diversity of extracellular polysaccharides in the biofilm is unique to the microorganism, a mixture of enzymes may be needed for sufficient degradation of bacterial biofilm.91
Enzymatic cleaners are effective at room temperature (ie, 68° F to 72° F [20° C to 22° C]) but function more effectively at warmer temperatures.19,69,89,120 A temperature that is too hot (ie, ≥ 140° F [≥ 60° C]) denatures proteins and may negate the desired enzymatic activity.69,120
Enzymatic cleaners are often recommended for cleaning flexible endoscopes and other medical devices because they help remove proteins, lipids, and carbohydrates by breaking down large molecules into smaller, water-soluble molecules that are easily rinsed away after cleaning83,122; however, the collective evidence conflicts regarding the benefits of using enzymatic cleaning solutions compared with nonenzymatic cleaners that may contain disinfectants or other chemicals to enhance cleaning and reduce viable bioburden.91,95,123 Decontamination is a physical or chemical process that removes or reduces the number of microorganisms or infectious agents and renders reusable medical devices safe for use, handling, or disposal.12,45,58 Decontamination requires a microbicidal process after cleaning.12,58 Microbicidal cleaning solutions do not eliminate the need for HLD or sterilization, but they may reduce the risk of exposure to biohazardous substances for processing personnel.22,120
In a quasi-experimental laboratory study, Merritt et al86 evaluated the effects of 12 different cleaning products, including enzymatic and nonenzymatic cleaning solutions, on organisms known to adhere to polystyrene and medical implant materials (ie, S epidermidis, C albicans, E coli, P aeruginosa). The results of the study showed that the enzymatic cleaners were effective at cleaning contaminated surfaces and removed all of the microorganisms while the solutions without enzymes were no more effective than utility water.
In a quasi-experimental laboratory study conducted to determine the effectiveness of five enzymatic and nine nonenzymatic cleaners on E coli biofilm, Henoun Loukili et al123 found that of the six products with the highest effectiveness scores (ie, mean percent activity of detergent > 70%), three were enzymatic cleaners and three were nonenzymatic cleaners. The three enzymatic cleaners had the highest scores (ie, 92%, 90%, 89%). The researchers concluded that enzymatic cleaners were not more effective than nonenzymatic cleaners. A major limitation of the study was that the enzymatic solutions were used at room temperature (ie, 68° F to 77° F [20° C to 25° C]), which may not have been in accordance with the manufacturers’ recommendations and may have affected overall performance. Another limitation was that the biofilm was prepared on a glass surface that is not representative of the materials used in many medical devices, including flexible endoscopes.
In a study to compare the effectiveness of enzymatic and nonenzymatic cleaners on E coli biofilm on the inner surface of gastroscopes, Fang et al124 randomly and equally assigned 15 Teflon® tubes coated with biofilm to one of three groups:
○ Group 1 tubes were treated with a one-minute wash with water, followed by a three-minute wash with enzymatic cleaner, followed by a one-minute wash with water.
○ Group 2 tubes were treated with a one-minute wash with water, followed by a three-minute wash with nonenzymatic cleaner, followed by a one-minute wash with water.
○ Group 3 tubes were treated with a one-minute wash with water, followed by a three-minute wash with sterile distilled water, followed by a one-minute wash with water.
The researchers found that although none of the cleaning solutions completely eliminated the biofilm, there was a 2.39-log10 CFU/tube reduction of bacterial burden in the nonenzymatic group compared with a 0.23-log10 CFU/tube reduction of bacterial burden in the enzymatic group. The researchers concluded that the nonenzymatic cleaners were more effective than the enzymatic cleaners. A limitation of this study was the use of only one bacterial biofilm. Another limitation was that the enzymatic cleaner was noted to be most effective at a temperature higher than room temperature (ie, 68° F [20° C]), but was used at 59° F (15° C). The researchers believed this temperature was more representative of the temperature at which enzymatic cleaning solutions are often used in actual practice.
In a study to evaluate the effects of various cleaning products and contact times on the removal of biofilm from flexible endoscopes, Ren et al95 randomly and equally assigned 60 Teflon tubes coated with E coli biofilm to one of four groups:
○ Group 1 tubes were treated with enzymatic cleaner 1.
○ Group 2 tubes were treated with enzymatic cleaner 2.
○ Group 3 tubes were treated with a nonenzymatic cleaner.
○ Group 4 tubes were treated with sterile water for injection.
The researchers found a statistically significant difference between the amount of residual biofilm in the enzymatic groups (Group 1 = 4.61 ± 0.52 CFU/cm2; Group 2 = 4.67 ± 0.59 CFU/cm2) compared with the nonenzymatic group (1.29 ± 0.13 CFU/cm2). Both enzymatic and nonenzymatic cleaners demonstrated the ability to remove biofilm; however, the amount of biofilm removal was greater with the nonenzymatic cleaner. A limitation of this study was the use of only one bacterial biofilm, although the researchers noted that E coli is a major component of normal intestinal flora and source of bacterial contamination of gastrointestinal endoscopes.95
In a quasi-experimental laboratory study, Vickery et al125 tested the efficacy of four enzymatic cleaning solutions and one nonenzymatic cleaning product on Teflon and polyvinyl chloride tubes coated with E coli biofilm. The researchers found that the nonenzymatic cleaner resulted in a 4.7-log10 CFU/cm2 reduction in biofilm bacteria, while the most effective enzymatic cleaner resulted in only a 1.57-log10 CFU/cm2 reduction. Notably, the nonenzymatic cleaner used in the study was a quaternary ammonium disinfectant and for this reason would be expected to have a greater bacterial log reduction compared with cleaning solutions that are not microbicidal.126
Alfa and Jackson121 conducted a quasi-experimental laboratory study to evaluate the cleaning and bactericidal effectiveness of a hydrogen peroxide-based nonenzymatic cleaner compared with two enzymatic cleaners. Test organisms (Enterococcus faecalis, Salmonella choleraesuis, Staphylococcus aureus, P aeruginosa) were suspended in artificial test soil on polyvinyl chloride carriers and then exposed to the cleaning solutions. The nonenzymatic cleaner demonstrated a 5-log10 CFU/carrier reduction in microbial load, even in the presence of a dried organic challenge of E faecalis and S aureus. The researchers found that none of the enzymatic cleaners achieved this level of log reduction.
Marion et al127 recommended an approach for removing biofilm that involved the use of detachment-promoting cleaners in endoscope channels and automated washer-disinfectors. The researchers contaminated the operating channel of three new endoscopes with biofilm developed from human serum inoculated with a bacterial culture of P aeruginosa, S epidermidis, Enterobacter cloacae, and K pneumoniae. One endoscope was left untreated; two endoscopes were treated with different detachment-promoting cleaners. The treated endoscopes underwent a static brushing procedure that involved immersing the endoscope in the selected cleaner and brushing the contaminated operating channel for one minute using the manufacturer’s recommended cleaning brush, simulating a manual cleaning process. The treated endoscopes also underwent a dynamic flushing procedure that involved the use of a peristaltic pump to circulate the cleaner through the operating channel, simulating a mechanical cleaning process. The researchers examined the internal surfaces of the operating channel using SEM and found that the biofilm was completely removed by the detachment-promoting cleaners.
Perret-Vivancos et al128 reported the case of a highly contaminated colonoscope that was effectively treated with a combination of biofilm detachment-promoting agents. The treatment included application of a multienzymatic solution designed to digest the foundation where the biofilm was anchored, followed by an enriched detergent solution designed to detach the biofilm as a single unit. After the first treatment, the authors found there was a decrease in the contamination level but the biofilm was not completely eliminated. A second identical treatment was applied and showed a significant reduction in the amount of biofilm. After a third treatment, the biofilm was almost totally removed.
The authors speculated that using these detachment-promoting cleaners could represent an approach to biofilm control that might improve the efficacy of cleaning and reduce the risk of transmitting infections. In addition, these cleaners have the potential to reduce costs by allowing for salvage of endoscopes contaminated with biofilm or as a preventive mechanism to avoid accumulation of biofilm in endoscope channels.128 Further research is warranted.
VI.d.1. If the manufacturer’s recommended cleaning solution is not available, processing personnel should contact the endoscope manufacturer for recommendations for other cleaning solutions that may be used. [5: Benefits Balanced with Harms]
VI.d.2. Manual cleaning should be performed using a freshly prepared cleaning solution.12,13,15,16,27,69,83,84,89,98 Cleaning solutions should be changed before they become cloudy or discolored, and before there are visible particulates in the solution. [2: High Evidence]
Using a freshly prepared solution for each new cleaning process helps prevent cross contamination.12,13,15,16,27,69,83,84,89,98 Cleaning solutions are not microbicidal and may support bacterial growth if stored or reused beyond their expiration date.45,65,84,99,129 Repeated use of cleaning solutions decreases the amount of active ingredients in the solution and reduces cleaning efficacy. Residual contaminants in cleaning solutions could increase the potential for cross contamination.96 Bioburden is deposited in the cleaning solution during the cleaning process. Changing the cleaning solution minimizes bioburden.
In a nonexperimental study to investigate biofilm on endoscope channels, Ren-Pei et al96 collected 66 endoscope suction and biopsy channels and 13 water and air channels from 66 endoscopy centers in hospitals throughout China. They used SEM to examine biofilm on the inner surface of the channels. A total of 36 suction and biopsy channels (54.5%) and 10 water and air channels (76.9%) were found to have biofilm.
After examining the endoscope channels, the researchers sent a questionnaire to each of the 66 endoscopy centers to explore the correlation between endoscope processing procedures and the amount of biofilm in the endoscope channels. They divided the responses (N = 66) into hospitals without biofilm on endoscopes (Group A; n = 30), and hospitals with biofilm on endoscopes (Group B; n = 36). The researchers found that the proportion of reuse of enzymatic cleaning solutions in Group A was 60% (18 of 30), whereas in Group B the proportion was 91.6% (33 of 36) and in some cases, the cleaning solution was reused more than four times. The researchers concluded that the formation of biofilm on the endoscope channels could be related to reuse of cleaning solutions.96
VI.d.3. Additional products should not be added to the cleaning solution unless this is recommended by the manufacturer. [4: Limited Evidence]
Adding products that are not recommended by the manufacturer could cause a chemical reaction that could damage the endoscope or render the cleaning solution ineffective.83
VI.d.4. The cleaning solution manufacturer’s IFU should be followed for
conditions of storage58; and
[2: High Evidence]
Deviations from the manufacturer’s IFU may render the cleaning product ineffective.129
Water quality, including hardness, and pH can alter the effectiveness of cleaning solutions.25,90,119 The enzymes used in enzymatic cleaners may be most effective at a neutral pH and may be inactivated by a high or low pH.98
Using the product in the concentration recommended by the manufacturer helps ensure consistent and accurate cleaning chemistry.77 A weak solution may not effectively break down proteins and other organic material; a strong solution may produce an increased number of bubbles, creating air pockets that prohibit surface contact of the cleaning chemical with the endoscope.122,129 Undiluted or under-diluted enzymatic cleaning solutions are difficult to remove and may lead to residual cleaning solutions and proteinaceous material in the endoscope that provide a foundation for biofilm formation and lead to processing failures.
If the water temperature is not warm enough, the cleaning product may not mix with the water as intended,122,129 and the enzymes may not be able to effectively dissolve and remove organic soil.25 If the temperature is too hot, it may cause coagulation of proteins and fix proteinaceous soil to the endoscope.25
Hutchisson and LeBlanc98 conducted a quasi-experimental study to demonstrate the need to follow the manufacturer’s IFU when using enzymatic cleaning solutions. The researchers tested five colonoscopes used during procedures at a Texas hospital after precleaning at the point of use, and then manually cleaned them using a low-sudsing enzymatic cleaner in the following formulations:
Endoscope 1: 1 oz of low-sudsing enzymatic cleaner in 1 gallon of water followed by a water rinse.
Endoscope 2: 2 oz of low-sudsing enzymatic cleaner in 1 gallon of water followed by a water rinse.
Endoscope 3: 4 oz of low-sudsing enzymatic cleaner in 1 gallon of water followed by a water rinse.
Endoscope 4: 1 oz of low-sudsing enzymatic cleaner in 1 gallon of water with no rinse.
Endoscope 5: undiluted low-sudsing enzymatic cleaner followed by a water rinse.
The manufacturer’s IFU called for 1 oz of enzymatic cleaner in 1 gallon of water.
After manual cleaning, the colonoscopes were mechanically processed, rinsed, and disinfected with orthophalaldehyde. They were hung vertically to dry without an alcohol flush. An absorbent white cloth was placed on the floor of the endoscope cabinet to catch effluent dripping from the distal tips of the endoscopes. Orthophalaldehyde reacts with residual bioburden to form dark stains. The researchers observed no staining of proteinaceous material with Endoscope 1 that had been cleaned with correctly diluted cleaning solution followed by a water rinse. The researchers observed some staining with Endoscope 4 that had been cleaned with correctly diluted cleaning solution but not rinsed. They observed significant staining with Endoscopes 2, 3, and 5 that were cleaned with underdiluted and nondiluted cleaning solution and then rinsed.98
The results of the study demonstrated that when endoscopes were cleaned using incorrect dilutions of cleaning solutions, small amounts of residual proteinaceous material was left on the interior and exterior surfaces of the endoscope. There could be a buildup of this residual material over time, which raises concerns about cleaning effectiveness as well as the potential negative effect of residual buildup on the optimal functioning and life of the endoscope.98
VI.d.5. An automated titration unit may be used to concentrate cleaning products at a consistent ratio.58 [5: Benefits Balanced with Harms]
The concentration of the solution can vary when it is mixed manually. Using a titration unit can aid in accurate measurement of the chemical during preparation of the cleaning solution and help personnel to consistently obtain the recommended concentration of the cleaning product.58
VI.d.6. Cleaning solutions should be changed when the temperature of the solution does not meet the temperature specified in the manufacturer’s IFU.77 A digital temperature measuring device may be used to monitor the temperature of the cleaning solution. [4: Limited Evidence]
Cleaning solutions may not be effective when used at temperatures outside of the manufacturer-specified parameters.
VI.e. The endoscope should be completely submerged in the cleaning solution during the cleaning process.12,13,16,20,22,65,84,85,89 Removable parts (eg, valves, buttons, caps) should be detached from the endoscope and submerged if recommended by the endoscope manufacturer’s IFU.85 [2: High Evidence]
Cleaning the endoscope under the surface of the solution helps prevent splashing of the contaminated solution and reduces the potential for aerosolization and exposure to biohazardous substances.16 Detaching removable parts and completely submerging the endoscope and removable parts helps ensure contact between the cleaning solution and all surfaces of the endoscope.65
VI.f. All exterior surfaces of the endoscope (Figure 6) should be cleaned with a soft, lint-free cloth or sponge saturated with the cleaning solution.1,12,13,15,16,18,19,22,27,65,83,84,89,105 [2: High Evidence]
Washing the external surfaces of the endoscope helps remove organic material that remains after precleaning.
VI.g. All accessible channels and the distal end of the endoscope should be cleaned with a cleaning brush of the length, width, and material recommended by the endoscope manufacturer.1,13,15,18,19,22,45,65,83,85,89,105,129 The endoscope valves should be manually actuated while cleaning.12,19,22 [2: High Evidence]
The collective evidence supports thorough and careful brushing of the accessible endoscope channels (Figure 7) with a correctly-sized brush as a method of dislodging and removing organic material and biofilm.1,18,45 Cleaning the distal end helps ensure there is no debris or tissue lodged in or around the water nozzle and suction biopsy channel.85 The presence and buildup of organic material in the lumens of endoscopes can have significant implications, including toxic reactions, device damage, inadequate disinfection or sterilization, increased risk of biofilm development, and the potential transmission of infection.130,131
Using the correct-size brush increases contact between the brush and the walls of the endoscope channels and maximizes the amount of soil removed.19,129 If the brush is too small, it will not make contact with the organic material or channel walls.129 If the brush is too large, it may get lodged in the channel and cause damage to the internal channels, or the bristles may be deflected upward, only swiping the sides of the channel and not effectively removing organic material or contacting the channel walls.129 Some endoscopes will require the use of two different brush sizes for effective cleaning.129
Pineau and De Philippe132 assessed 206 samples from flexible endoscopes (ie, 87 colonoscopes, 93 gastroscopes, 26 bronchoscopes) from four different hospitals in France for levels of bioburden. In this nonexperimental study, the researchers compared samples that had been collected
○ after point-of-use precleaning (n = 30);
○ after point-of-use precleaning and manual brushing of channels (n = 34);
○ after point-of-use precleaning, manual brushing of channels, and double washing and rinsing in a mechanical processor (n = 111); and
○ after point-of-use precleaning, manual brushing of channels, double washing and rinsing in a mechanical processor, and HLD in a mechanical processor (n = 31).
The researchers found that brushing significantly reduced the contamination present in the endoscope channels after point-of-use precleaning. Brushing endoscope channels reduced the number of viable bacteria by at least 2.5-log10/cm2. The researchers concluded that brushing was important for reducing contamination remaining in endoscopes after point-of-use precleaning.
In a quasi-experimental laboratory study, Dietze et al133 investigated the influence of design on the efficacy of manual cleaning of endoscope channels. The researchers tested two duodenoscopes and two gastroscopes. The air channels of one duodenoscope (A) and one gastroscope (B) were freely accessible and able to be flushed and brushed. The air channels of the other duodenoscope (C) and the other gastroscope (D) were only able to be flushed. The researchers contaminated the air channels of all four endoscopes with blood containing Enterococcus faecium as a test organism. They implemented manual cleaning by flushing and brushing for endoscopes A and B and flushing only for endoscopes C and D and then calculated the recovery rates.
The researchers found that the rate of microorganisms recovered after flushing alone was between 4.8 × 105 CFU/180 mL and 5.8 × 105 CFU/180 mL. The rate of microorganisms recovered after flushing and brushing was between 1.6 × 107 CFU/180 mL and 2.3 × 107 CFU/180 mL. This indicated that the cleaning rate for flushing alone was only 2.6% of the cleaning rate obtained by flushing and brushing.133
In a quasi-experimental study, Ishino et al134 alternately assigned endoscopes used for upper gastrointestinal examinations into Group A (n = 20), where the air and water channels were brushed three times with a sterile, correctly sized brush, and Group B (n = 22), where the air and water channels were not brushed. The researchers examined the endoscope channels using a protein-staining dye and found no residual protein in the air channels of either Group A or Group B endoscopes. The water channels of the Group A endoscopes also had no residual protein; however, one water channel from the Group B endoscopes did have residual protein. The researchers concluded that the protein-aceous material remaining in the water channel of the non-brushed endoscope was likely organic debris, and unless removed by brushing, this material could become fixed on the inner surface of the endoscope channels and become a potential source of infection.
Bajolet et al118 reported transmission of an extended-spectrum ß-lactamase-producing P aeruginosa in four patients who underwent esophagogastroduodenoscopy (EGD) procedures with the same gastroscope between May 2011 and August 2011. The gastroscope had been purchased in January 2011. Microbiological sampling before its first use showed negative results. Observation of the endoscope processing procedures during the investigation identified cleaning failures that included inadequate brushing and flushing of the channels and the use of a single-diameter cleaning brush for all gastrointestinal endoscopes. The investigators concluded that the lack of sufficient cleaning and the use of an incorrectly sized brush may have supported the development of a persistent biofilm that contributed to patient-to-patient transmission of a serious infection.
Agerton et al135 reported a case of transmission of multidrug-resistant M tuberculosis (MDR-TB) caused by a contaminated bronchoscope. Five patients from a South Carolina community who were family members or close friends were diagnosed with tuberculosis. Three additional patients were hospitalized in the same facility as one of the five patients diagnosed with tuberculosis. These three patients had bronchoscopy procedures performed with the same bronchoscope in the same hospital within 17 days of the tuberculosis patient. As a result of the contaminated bronchoscope, two patients had false-positive MDR-TB cultures from specimens obtained during their bronchoscopy procedures, and one patient developed and died from MDR-TB. A review of the processing procedures for bronchoscopes revealed that leak-testing equipment was available but never used, manual cleaning time averaged less than three minutes, and a cleaning brush was passed through the endoscope only one time.
VI.g.1. The elevator mechanism and the recesses surrounding it should be cleaned and brushed with a cleaning brush of the length, width, and material recommended by the endoscope manufacturer.1,6,13,15,22,45,65,83,85,89,129 The elevator should be raised and lowered throughout the manual cleaning process.6,85 [2: High Evidence]
Some duodenoscopes have a movable elevator channel at the distal end (Figure 8) that allows the accessory instrument to access the pancreatic and biliary ducts.6 The collective evidence shows that the complex design of the duodenoscope improves the efficiency and effectiveness of ERCP procedures; however, some parts of the endoscope may be extremely difficult to access, and this creates challenges for cleaning.6 In fact, effective cleaning of all areas of the duodenoscope may not be possible.6 The moving parts of the elevator mechanisms contain microscopic crevices that may not be reachable with a brush.6 Residual body fluids and organic material may remain in these crevices after cleaning and disinfection.6 If this fluid or material contains microbial contamination, subsequent patients may be exposed to serious infections.6,136,137 Although the risk of infection transmission associated with these complex devices cannot be completely eliminated, the benefits of treatment outweigh the risks in appropriately selected patients.138
Raising and lowering the elevator during the cleaning process helps ensure that no organic material is lodged in the moveable mechanism and allows for more effective brushing of all surfaces, including the base of the elevator apparatus.6,85,139
Alrabaa et al136 reported seven cases of carbapenemase-producing K pneumoniae in patients from two tertiary hospitals in South Florida between June 2008 and January 2009. All seven patients had ERCP procedures at the same outpatient endoscopy center within 60 days before the outbreak. Six patients had undergone procedures with a common endoscope.140 The endoscope was examined and found to have residual organic material under the elevator that cultured positive for carbapenemase-producing E coli, Pseudomonas, and Serratia species.140 The investigators observed processing procedures at the endoscopy center and found the cleaning procedure for the duodenoscopes was inadequate. The manufacturer’s IFU that required cleaning with a brush the complex terminal part of the endoscope that contains the elevator was not followed, and bioburden remained under the elevator of the endoscope after the cleaning process was completed. The investigators concluded that processing duodenoscopes was more complex than processing traditional endoscopes, and additional steps were required to ensure effective decontamination.140
The CDC141 reported an outbreak of New Delhi metallo-ß-lactamase-1 (NDM-1)-producing E coli involving 28 colonized and 10 infected patients. All 38 patients were exposed while undergoing ERCP in a Chicago hospital between January 2013 and September 2013. After manual cleaning and mechanical processing, the terminal section of a side-viewing duodenoscope used for five of the case patients remained culture-positive for NDM-1-producing E coli and carbapenemase-producing K pneumoniae, despite no obvious lapses in protocol. Although cultured from the same endoscope, no colonization or infections were identified from this second strain of carbapenem-resistant Enterobacteriaceae. The CDC observed that the design of ERCP endoscopes makes them particularly challenging to clean and disinfect. In an independent inspection of the hospital’s procedures, the Centers for Medicare & Medicaid Services reported that the hospital was using unapproved cleaning solutions and brushes and failed to process the endoscopes as recommended by the manufacturer.142,143
Wendorf et al137 described an outbreak of AmpC-producing E coli at a medical center in Seattle between November 2012 and August 2013. Thirty-two patients who had undergone ERCP procedures were found to harbor one of two genetically similar strains of the organism.144,145 The investigators found no violations of the recommended processing procedures. During the investigation, the endoscope manufacturer observed personnel manually cleaning and inspecting the endoscopes and concluded that the cleaning process was not only consistent with manufacturer guidelines, it was above the industry standard. Even after implementing procedures that included enhanced manual cleaning, the investigators found that gastrointestinal bacteria continued to be recovered from the endoscope elevator channels.137
Nine endoscopes, which included the eight endoscopes in use during the outbreak plus an additional endoscope, were evaluated by the manufacturer. The manufacturer found that all of the endoscopes (whether in need of repair or not) harbored pathogenic bacteria in the elevator channel and continued to have positive cultures even after repair. Notably, three of the endoscopes had passed leak tests at the hospital but failed the manufacturer’s leak test, and seven endoscopes were determined to have at least one critical defect. The investigators concluded that obscure mechanical defects in combination with the difficulty of cleaning the elevator channel facilitated the transmission of the infection.
Kola et al146 reported an outbreak of carbapenemase-resistant K pneumoniae (CRKP) associated with a contaminated duodenoscope in a German university hospital. Between December 2012 and January 2013, CRKP was cultured from 12 patients staying on four different wards. Molecular typing confirmed the close relation between all 12 isolates. Six of the patients were from the same ward; they were immediately transferred to separate rooms and placed on contact precautions. The remaining six patients had all undergone ERCP procedures with the same duodenoscope. Culturing the duodenoscope did not recover CRKP.
The investigators reviewed processing procedures for the duodenoscope and could find not deviations from the manufacturer’s IFU; however, they did obtain positive cultures for Enterococci, which they suggested was indicative of insufficient cleaning. The duodenoscope was sent to the manufacturer who found a defective distal cap. The outbreak ended when the duodenoscope was removed from service. The investigators concluded that the processing procedures may not have been sufficient in every case because of the complex physical design of the distal end of the duodenoscope.146
Verfaillie et al147 reported a large outbreak of Verona integron-encoded metallo-ß-lactamase (VIM)-2-producing P aeruginosa linked to the use of a duodenoscope with a sealed elevator channel intended to obviate the need for special cleaning measures. Between January 2012 and April 2012, 30 patients were identified with a VIM-2-positive P aeruginosa; 22 of these patients had undergone ERCP with the same duodenoscope. The investigators confirmed that the strain in all 22 cases was identical to the strain that was cultured from the recess under the forceps elevator of the duodenoscope. Dismantling the distal end of the duodenoscope revealed that the sealed elevator channel design may have hampered effective cleaning. The outbreak resolved when the endoscope was withdrawn from clinical use.
VI.g.2. A clean brush should be used for each endoscope cleaning. Brushes and other items used to clean endoscope channels should be visually inspected before use and should not be used if the integrity of the brush or other cleaning item is in question.89 [3: Moderate Evidence]
Using a clean brush for each cleaning of the endoscope helps prevent cross contamination. Verifying the brush is intact and safe to use (ie, the protective tip is present, the coiling is braided, all bristles are present, the delivery tube is not kinked) assists with effective cleaning and helps prevent damage to the endoscope.129
Behnia et al148 reported a pseudo-outbreak of Stenotrophomonas maltophilia and Acinetobacter baumannii in six patients in a community hospital in Augusta, Georgia. The source was traced to a contaminated bronchoscope that had been used in two ICUs at the same hospital. The investigators reviewed the processing procedures for the bronchoscope and found that brushes intended for single-use were being shared between several different bronchoscopes and were not discarded after each use.
VI.g.3. The accessible channels of the endoscope should be brushed multiple times until no debris appears on the brush.12,13,15,16,20,21,27,45,65,83,85,89 Debris should be removed from the brush before the brush is retracted back through the channel and after each pass by swirling the brush in the cleaning solution and rinsing it.13,15,16,,65,83,85,89 [2: High Evidence]
VI.g.4. New technologies for brush design and lumen cleaning may be used when compatible with the endoscope. [3: Moderate Evidence]
There is discussion in the literature regarding the need for enhanced brush design to improve cleaning efficacy, decrease brushing time and effort, and reduce the potential for exposure of processing personnel to biohazardous material.
In a quasi-experimental laboratory study to evaluate protein deposits and removal in the channels of flexible endoscopes, Hervé and Keevil130 took 8-inch (20-cm) sections of new endoscope biopsy and air and water channels and contaminated them with artificial test soil. An enzymatic cleaner and single-use endoscope brushes were used to clean the soiled channel sections by inserting the brush head at one end of the channel section and pushing it out the other end. This brushing maneuver was repeated several times. The channel sections were then flushed with deionized water and purged with air. After cleaning, dye was injected into the lumen, which was then rinsed with deionized water and purged with air. The channel sections were examined with an episcopic differential contrast/epifluorescence microscope.
The researchers found that brushing the channels did not remove proteinaceous residues because endoscope channels adsorb proteins as a thin film on the internal surfaces. Brushing did have some beneficial effect; however, brushing also appeared to increase microcontamination. The researchers suggested that because prions represent the proteinaceous contamination most resistant to decontamination, this inability to completely remove proteinaceous contamination could be problematic in countries with a population at risk for variant Creutzfeldt-Jakob disease (vCJD); however, the risk of transmission was unclear. They posited that the cleaning outcome could be improved with better brush design.130
New technologies for brush design and lumen cleaning may be more effective and less damaging to the internal lumens of flexible endoscopes. Charlton149 compared the cleaning efficacy of a lumen-cleaning device to three lumen-cleaning brushes (ie, triple-headed brush, single-use brush, reusable brush). The lumen-cleaning device had elastomer discs designed to make contact with the internal walls of the endoscope channels and wipe soil from the surface as it is pulled through the channel. In this nonexperimental laboratory study, the researchers applied simulated blood soil to the lumens of two different-sized endoscope channels (ie, 2.8 mm, 5.0 mm) that had been removed from used endoscopes during servicing. The lumen-cleaning device was passed through the soiled lumens one time. The lumen-cleaning brushes were pushed down and then pulled up through the lumen three times. The researchers found there was very little residual soil in the lumen cleaned with the lumen-cleaning device and substantial quantities of soil in the lumens cleaned with the lumen-cleaning brushes. The lumen-cleaning device removed significantly more soil (92%) compared with the lumen-cleaning brushes (52% to 65%).
The researchers noted that multiple passes with a brush was more time-consuming than a single pass with the lumen-cleaning device. They suggested that the lumen-cleaning device was safer to use than a brush because the lumen-cleaning device emerged only once from the contaminated channel compared with the cleaning motion for brushing that requires the brush to emerge multiple times from the contaminated channel. As the tip of the brush emerges from the lumen, the bristles have the potential to flick soil into the environment, onto other parts of the endoscope, or onto other instruments, increasing the risk for cross contamination and the potential for biohazardous spray and splatter. Brushes may also increase the formation of biofilm by causing surface abrasion or grooves in the channel wall. Notably, this study was funded by the manufacturer of the lumen-cleaning device.149
Charlton150 conducted a second nonexperimental study in a clinical setting to compare the lumen-cleaning device used in the previous laboratory study to reusable lumen-cleaning brushes. The study was completed during a four-day period in an endoscopy clinic of a major hospital in Sydney, Australia. Immediately after the endoscope was removed from the patient, a sterile saline solution was flushed down the biopsy channel of the endoscope and submitted for microbiological sampling. The endoscope was cleaned using either one pass of the lumen-cleaning device (n = 26), or three passes (ie, pushed down and then pulled up through the lumen) of the reusable cleaning brush (n = 27), and a second microbiological sample was submitted.
The researchers found no significant difference between the effectiveness of the lumen-cleaning device compared with the reusable lumen-cleaning brushes. The lumen-cleaning devices reduced CFU by 3.302-log10/cm2. The reusable lumen-cleaning brushes reduced CFU by 3.003-log10/cm2. The researchers concluded that one pass of the lumen-cleaning device was as effective as three passes of the reusable lumen-cleaning brushes. Notably, this study was funded by the manufacturer of the lumen-cleaning device.150
A report of a study prepared by High-power Validation Testing & Lab Services151 detailed the methods used to evaluate and compare the cleaning efficacy of a unique microfiber endoscopic channel brush and the endoscope manufacturer’s recommended cleaning brush. The researchers extracted the endoscope cleaning channels, inoculated them with artificial test soil containing blood and protein, allowed the soil to dry for 24 hours, and compared the effectiveness of the brushes in removing the soil. The results showed that the microfiber channel brush removed 99.98% of the soil (ie, a 4-log reduction). The manufacturer’s recommended cleaning brush removed 93.35% of the soil (ie, a 1.2-log reduction). Notably, this study was funded by the manufacturer of the microfiber endoscopic channel brush. Further research is warranted.
VI.h. The channels of the endoscope should be flushed with cleaning solution.12,15–17,19–21,27,89 A cleaning adapter or automatic flushing system may be used when compatible with the endoscope.12 [2: High Evidence]
Flushing all internal channels helps dislodge and remove organic material and biofilm and exposes these surfaces to the cleaning solution.27 Cleaning adapters and automatic flushing systems facilitates opening of the ports and cleaning of the channels.1
VI.i. The exterior surfaces and internal channels of the endoscope should be flushed and rinsed with utility water until all cleaning solution and residual debris is removed.12,13,15–17,20,27,83–85,89 [2: High Evidence]
Thorough flushing of the channels and rinsing of the endoscope with utility water helps remove residual debris and cleaning solutions and prevents dilution of the high-level disinfectant or liquid chemical sterilant.13,16,65,89,90 If not adequately rinsed, enzymatic cleaning solutions may contribute to protein buildup within the endoscope channels.131
Moisture remaining on the surface or in the endoscope lumens may dilute the high-level disinfectant or interfere with the sterilization process, potentially reducing its effectiveness.13,16,84 Hydrogen peroxide vapor and hydrogen peroxide gas plasma sterilization cycles may abort in the presence of excess moisture.40 Ethylene oxide combines with water to form ethylene glycol (ie, antifreeze), which is toxic and not removed during aeration.41
VI.k. Reusable parts (eg, valves, buttons, port covers, tubing, water bottles), accessories (eg, forceps), and cleaning implements (eg, brushes, channel cleaning adapters) should be cleaned, brushed, rinsed, and high-level disinfected or sterilized.1,12,13,17–21,27,44,83,89,152,153 [1: Strong Evidence]
Effective processing of reusable endoscope parts and accessories is necessary for safe and successful treatment of patients.120,152,154 Reusable brushes that are not decontaminated can cause contaminants to be transferred from one device to another.58
The FDA155 has received reports that, in the absence of a valve to prevent backflow, patient fluids such as blood and stool can travel through the auxiliary water channel and into the water inlet and irrigation system; however, there have been no reports of infection directly attributed to backflow. The FDA recommends that the following be processed or replaced after each patient use:
○ any device directly connected to the auxiliary water inlet (up to and including the distal valve in the fluid pathway),155
○ the one-way valve in the auxiliary water channel of an endoscope with an internal one-way valve,155 and
○ any device directly connected to the biopsy channel (up to and including the distal oneway valve in the fluid path).155
The Department of Veterans Affairs156 reported an incident involving a patient who underwent a colonoscopy procedure. During the procedure, the endoscopy team noticed blood in the tubing of the auxiliary water system used for irrigation during procedures. The equipment was taken out of service and an investigation was initiated. The investigators found that a required one-way valve had not been used during the procedure, the tubings had been incorrectly connected, and the tubings were not being disinfected or discarded according to the manufacturer’s IFU. Notably, both connectors were the same color and roughly the same size and shape. The investigators were unable to determine when or why the switch occurred. Likewise, they were unable to determine how long the required one-way valve had not been in use.
VI.k.1. Water and irrigation bottles should be high-level disinfected or sterilized at least daily.22,44,45,93,153 There should be no residual water or moisture remaining in the water-bottle assembly.153,157 [1: Strong Evidence]
Water bottles consist of the water container, cap, and tubing used for insufflation of air and lens washing.153 Irrigation bottles consist of the water container, tubing, and accessories used to flush water through the endoscope.153
Water and irrigation bottles can be a source of endoscope contamination22; however, the optimal frequency for replacing, disinfecting, or sterilizing them has not been established and warrants further research.44 Residual water remaining in the water-bottle assembly may support bacterial growth.
The collective evidence conflicts regarding the need for sterile water in the water and irrigation bottles, and further research is warranted. The American Society for Gastrointestinal Endoscopy (ASGE) recommends using utility water in irrigation bottles because the rates of bacterial contamination are similar with the use of utility water and sterile water and neither has been associated with clinical infections.30 This conflicts with the recommendation for using sterile water provided in the “Multi-society guideline on processing flexible gastrointestinal endoscopes.”44 Using sterile water is also recommended by some professional organizations to help prevent contamination from organisms in utility water1,22,44,45,153; however, there is a small amount of evidence that indicates this may not be necessary.158–160
In a two-phase quasi-experimental study to determine whether the endoscope water source holds potential for transmission of infection, Puterbaugh et al158 compared utility water in clean water bottles (Phase 1; n = 303) with sterile water in sterile water bottles (Phase 2; n = 106). The researchers took cultures of the water in the bottles before starting and after completing the day’s procedures. The researchers found that 29 (9.6%) of the samples from Phase 1 were positive for normal flora found in city water. Four of the samples from Phase 2 (3.8%) were positive for similar bacteria. They concluded that the use of utility water in clean water bottles carried no greater risk than using sterile water in sterile water bottles.
Wilcox et al159 conducted a quasi-experimental study in a university teaching hospital to determine whether there was a need for sterile water in the water bottles used during endoscopy procedures. During a 12-week period, the water bottles were sterilized weekly and then filled with either sterile or utility water. At the end of each week, the remaining water in the bottles was cultured. During the study period, 437 procedures were performed and 36 cultures were submitted. Nine of the cultures were positive, including three cultures from bottles where sterile water had been used. The bacterial isolates included Flavobacterium species (n = 5), Acinetobacter species (n = 4), Pseudomonas species (n = 2), and Stenotrophomonas maltophilia (n = 1). Colony counts ranged from 900/mL to more than 10,000/mL. No patient developed infections from any of the organisms recovered. The researchers concluded that the use of utility water compared with sterile water may be reasonable and may also reduce costs.
In response to this study, Patton et al161 countered that utility water contains minerals that can leave deposits on flexible endoscopes and in the channels of the endoscope. The mineral deposits could lead to a costly repair or a need to replace the endoscope. The author estimated repair costs at $1,000 to $5,500 ($1,470.59 to $8,088.24 in 2015 US dollars) and noted that the cost of a 1,000 mL bottle of sterile water was $2.38 ($3.50 in 2015 US dollars); therefore, several cases of sterile water were less expensive than a single repair. The author concluded that using sterile water would not only decrease the risk of transmission of pathogenic organisms, it would also decrease the need for repair or replacement of the endoscope.
In an expert opinion piece, Rockey160 debated the need for sterile water in water bottles, stating there was no evidence to support the concern that using utility water could damage the endoscope and contending that it would take years for mineral deposits to form. If mineral deposits were to form on the internal channels of the endoscope, they would likely be washed away by the force of the fluid flushed through the channels during mechanical processing. The author further stated that using sterile water is necessary when entering sterile body cavities, but should not be necessary when entering portions of the gastrointestinal tract that are not sterile since utility water is acceptable for drinking. Likewise, utility water is used in other body systems without complication (eg, oxygen humidification).
VI.k.3. Insulated electrosurgical devices used during endoscopic procedures should be processed in accordance with the AORN Guideline for Cleaning and Care of Surgical Instruments58 and handled in accordance with the AORN Guideline for Electrosurgery.162 [1: Strong Evidence]
VI.l. Single-use parts, accessories, and cleaning implements may be used when compatible with the endoscope. [1: Strong Evidence]
The intricate design and configuration of certain components and accessories used with flexible endoscopes represent a significant challenge to cleaning.154 Using single-use products may be helpful in reducing the risk of cross contamination from reusable products.18,27,120 Using single-use brushes may help ensure that a clean brush is used each time.58
Parente154 conducted a nonexperimental study to evaluate the difficulty with manual cleaning and disinfection of endoscopic biopsy port valves. The researchers collected 15 reusable biopsy port valves from three endoscopy centers across the United States. The valves had been reprocessed and were deemed to be clean, disinfected, and ready for use. The biopsy port valves were examined using brightfield microscopy and then further studied to identify potential sources of contamination using Fourier transform infrared spectroscopy. The researchers found that eight of the 15 valves (53.3%) exhibited some form of debris or potential contamination. Testing confirmed the debris to be proteinaceous material. The researchers also found that many of the valves were damaged, increasing the potential for leakage and providing reservoirs for bacterial colonization. At least one valve came from each of the three facilities. The researchers concluded that single-use biopsy port valves provided a higher degree of patient safety.
Wilson et al163 reported a pseudo-outbreak of Aureobasidium species found in 10 broncheoalveolar lavage fluid cultures taken from nine patients between June 1998 and August 1998. Based on the clinical and laboratory data, there did not appear to be a true infection in any of the patients; however, all of the patients had their bronchoscopy procedures performed in the same outpatient bronchoscopy suite. The investigators observed the processing procedures and found that single-use plastic stopcocks were routinely being reused. The stopcocks were attached to sterile syringes containing sterile water used for the broncheoalveolar lavage. After each use, the stopcocks were manually washed and placed into a mechanical processor. Notably, the manufacturer of the mechanical processor did not recommend disinfecting the stopcocks in this manner.
After HLD, the stopcocks were stored in a sterile, plastic container with a screw top. At the time of the investigation, the container held approximately 20 stopcocks. There was no record of how many times each stopcock was being reused. Culture of the stopcocks yielded heavy growth of Aurebasidium species. The practice of reusing the single-use stopcocks was discontinued.163
Flexible endoscopes, accessories, and associated equipment should be visually inspected for cleanliness, integrity, and function before use, during the procedure, after the procedure, after cleaning, and before disinfection or sterilization.
The collective evidence supports visual inspection of endoscopes, accessories, and equipment after cleaning and throughout use and processing as a method to help identify residual organic material and defective items in need of repair.1,12,13,21,58,65,90
The benefits are that visual inspection and evaluation provide an opportunity to identify and remove from service soiled or defective items that might put patients at risk for infection or injury until these items are cleaned or repaired.24,58
VII.a. Before use, all new, repaired, refurbished, and loaned endoscopes, accessories, or other equipment should be visually inspected and processed according to the manufacturer’s IFU. [5: Benefits Balanced with Harms]
It is not possible to verify how all new, repaired, refurbished, or loaned equipment and devices have been handled, cleaned, inspected, or processed before receipt in the facility. Failure to correctly clean, inspect, or process an item may lead to transmission of pathogenic microorganisms from a contaminated device and create a risk for patient injury or infection.
Visually inspecting endoscopes, accessories, and equipment upon receipt and before processing can help verify there are no obvious defects and may prevent damaged or malfunctioning endoscopes from being used on patients.
VII.b. Endoscopes, accessories, and equipment should be visually inspected and evaluated for
○ physical or chemical damage,106 and
[2: High Evidence]
Visual inspection and evaluation helps detect the presence of residual soil and identify items in need of repair.
An endoscope that appears clean may harbor debris that cannot be seen without magnification. Lighted magnification may increase the ability to identify residual soil or damage.
Identification of defective endoscopes, accessories, and equipment and removal from service reduces the risk of a defective item being used and helps prevent further damage from use.84
VII.d.1. Medical equipment being sent for repair must be decontaminated to the fullest extent possible and a biohazard label attached before transportation.48 [1: Regulatory Requirement]
Decontaminating and labeling medical equipment before transport is a regulatory requirement and communicates to others which portions of the device being transported are contaminated.48
Incorrectly preparing the item being sent for repair may further damage the item and expose personnel handling the item to contaminants.
The manufacturer or service representative may provide recommendations that align with regulatory requirements for safe processes to follow for return or repair of the endoscope.85
After manual cleaning and inspection, flexible endoscopes and endoscope accessories should be high-level disinfected or sterilized.45
The Spaulding classification system, developed by Earl Spaulding in 1968, classifies items as critical, semicritical, or noncritical.117 The level of processing required (ie, sterilization, HLD, intermediate-level disinfection [ILD], low-level disinfection) is based on the nature of the item that requires processing and the manner in which the item is to be used.117 The classification system has been used by infection preventionists and others for more than 47 years.164
According to the Spaulding classification, devices that enter sterile tissue or the vascular system are considered critical items.117 When critical items, such as biopsy forceps, are contaminated with microorganisms, the risk of infection transmission is substantial.117 Therefore, Spaulding et al117 recommended that critical items be processed by sterilization. Sterilization eliminates all microbial life, including pathogenic and nonpathogenic microorganisms and bacterial spores.117 Notably, sterilization is a validated process used to render a product free from all forms of viable microorganisms.155 Liquid chemical sterilization may not convey the same sterility assurance as sterilization using thermal or other low-temperature sterilization methods.155
Items such as flexible endoscopes that come in contact with nonintact skin or mucous membranes, are considered to be semicritical.117 Mucous membranes provide a barrier to common bacterial spores, but not to organisms such as tubercle bacilli and viruses.117 Therefore, Spaulding et al117 recommended that semicritical items be processed by sterilization, or at a minimum, by HLD. High-level disinfection eliminates all pathogenic microorganisms except for small numbers of bacterial spores.46,117
VIII.a. A multidisciplinary team that includes infection preventionists, endoscopy and perioperative RNs, sterile processing personnel, endoscopists, and other involved personnel should conduct a risk assessment to determine whether items that secondarily enter sterile tissue or the vascular system (ie, via a mucous membrane) should be sterile. [3: Moderate Evidence]
At a meeting of the Gastroenterology-Urology Devices Panel convened by the FDA in May 2015 to seek expert scientific and clinical opinion related to reprocessing of duodenoscopes and other flexible endoscopes, Rutala proposed a modification of the Spaulding system wherein items that secondarily enter sterile tissue or the vascular system are considered to be critical items (Table 2).165 Devices secondarily entering sterile tissue would include devices that enter sterile tissue by way of a mucous membrane, such as a bronchoscope, a cystoscope, or a duodenoscope.165 For example, a bronchoscope enters the bronchi through the mouth or nose, a cystoscope enters the bladder through the urethra, and a duodenoscope enters the bile or pancreatic ducts through the mouth. Requiring sterilization of items that secondarily enter sterile tissue or the vascular system may help prevent patient infection.
The collective evidence shows there are challenges to implementing the current Spaulding classification system when processing complex, heat-sensitive devices such as flexible endoscopes.120 Because of the heavy microbial load that may be present on some flexible endoscopes and the difficulty in cleaning and disinfecting long, narrow channels, current HLD processes may not be adequate to ensure flexible endoscopes are safe for use on patients.166
The Spaulding classification does not address how to process semicritical items used in conjunction with critical items.120 Although flexible endoscopes are categorized as semicritical, the accessory devices used in combination with flexible endoscopes may be critical items because they enter sterile tissue or the vascular system.120 These critical items are passed through an endoscope categorized as semicritical, which requires a minimum of HLD rather than sterilization.120 Endoscopic accessories may emerge from the distal end of the endoscope and contact the mucosal surface of the bowel, bladder, or esophagus before they are used for the procedure. In addition, the Spaulding classification does not address the need for inactivating certain types of infectious agents, such as prions.120 Thus, there are concerns about whether semicritical items should be sterilized rather than high-level disinfected.165,167
Incidents of reduced susceptibility to aldehyde disinfectants and high-level disinfectant failure also have been reported.164,168,169 Tschudin-Sutter et al168 detected P aeruginosa in 23 of 73 routine samples (32%) obtained from endoscopes during November 2009, and in 29 of 99 investigational samples (29%) obtained between November 4, and December 7, 2009. The investigators observed endoscope processing procedures and found no lapses; however, they noted that the drying time on the mechanical processor had been reduced from 10 minutes to 5 minutes to expedite turnaround time.
Environmental samples were obtained, and P aeruginosa was detected in the rinsing water and in the drain of one of the mechanical processors. The pathogen could not be detected in the water pipes or in any of the cleaning solutions or disinfectants used for processing the endoscopes. Infectious disease specialists reviewed medical records and detected six patients with lower respiratory tract and bloodstream infections possibly caused by the pseudo-outbreak strain. The investigators found that the glutaraldehyde-based disinfectant demonstrated no activity against the microorganism when used in the recommended concentration and at the recommended temperature. They concluded the P aeruginosa was resistant to the glutaraldehyde disinfectant.168
In a quasi-experimental study to investigate the potential for bacterial resistance in mechanical processors using aldehyde disinfectants, Fisher et al169 randomly sampled three mechanical processors in the United States using aldehydes for HLD of flexible endoscopes. The researchers found bacterial contamination after disinfection in all of the mechanical processors and found that some mycobacteria isolates demonstrated significant resistance to glutaraldehyde and orthophalaldehyde disinfectants. The researchers concluded that bacteria can survive aldehyde-based HLD and may pose a cross contamination risk to patients.
In some outbreaks and pseudo-outbreaks, resolution was only achieved when the endoscope was sterilized by ethylene oxide.166,170–172 Epstein et al170 conducted a case control study to identify the source and interrupt transmission of NDM-producing carbapenem-resistant E coli in a tertiary care hospital in northeastern Illinois. The investigators identified 39 case patients from January 2013 through December 2013, of whom 35 had undergone ERCP procedures in the same hospital. No lapses in duodenoscope processing were identified; however, NDM-producing E coli that shared a 92% genetic similarity to all case patients was recovered from a processed duodenoscope. After the investigators changed from using from HLD with orthophalaldehyde to sterilization with ethylene oxide, the duodenoscopes were culture-negative and no additional case patients were identified.
Between October and December 2010, Chang et al173 identified ertapenem-resistant E cloacae in the urine cultures of 15 patients who had undergone ureteroscopy with the same ureteroscope. The investigators did not find any breaches in the processing procedures. The endoscope was culture-positive for the ertapenem-resistant E cloacae. The ureteroscope was meticulously cleaned and high-level disinfected for an additional five minutes beyond the manufacturer’s recommended HLD time. The ureteroscope was sampled, and the results were again culture-positive. The ureteroscope was sterilized with ethylene oxide, sampled, and found to be culture-negative.
Smith et al174 questioned current processing guidelines for duodenoscopes in a report describing transmission of carbapenem-resistant Enterobacteriaceae. Between May and November 2013, three patients at a Wisconsin medical center were identified as having NDM-1 carbapenem-resistant E coli after undergoing ERCP procedures with the same duodenoscope. The investigators observed the processing procedures and found no lapses. They sampled the duodenoscope and found it was culture-negative; however, the evidence was sufficiently strong to implicate the duodenoscope as the mode of transmission. The duodenoscope was sterilized with ethylene oxide and no additional infections were diagnosed. The researchers noted that for procedures in which duodenoscopes were used, there may be a risk of transmission of infection despite HLD.
Müller et al175 described infections of multidrug-resistant P aeruginosa in two patients who had undergone ERCP procedures with the same duodenoscope for which sterilization by ethylene oxide did not eliminate the organism. The endoscope was quarantined and sampled and found to be culture-positive for the same strain of P aeruginosa as the infected patients. The endoscope was manually cleaned, soaked in 2% glutaraldehyde for 10 hours, sampled, and again found to be culture-positive. The duodenoscope was then sterilized with ethylene oxide, sampled, and once again found to be culture-positive. The endoscope was returned to the manufacturer for replacement of all internal channels. The investigators concluded that constant vigilance related to processes for cleaning and HLD was needed to ensure safe and effective processing of endoscopes.
Notably, many facilities do not have the capability of performing ethylene oxide sterilization. Sterilization and aeration using ethylene oxide may take 12 to 15 hours or more.166 Penetration of ethylene oxide into long, narrow lumens is a concern, and flexible endoscopes may not have been validated by the manufacturer for sterilization with ethylene oxide.120
In a quasi-experimental laboratory study, Alfa et al176 assessed the effect of serum and salt on the performance of two 100% ethylene oxide sterilizers, two ion plasma sterilizers, a vaporized hydrogen peroxide sterilizer, and a 12/88 ethylene oxide sterilizer. The researchers inoculated test carriers with E coli, E faecalis, P aeruginosa, Mycobacterium chelonae, Bacillus stearothermophilus spores, Bacillus subtilis spores, and Bacillus circulans spores; subjected them to sterilization; and calculated the residual bacterial load. The inoculum was prepared with and without 10% serum and 0.65% salt. The researchers found that all of the sterilizers effected a 6-log reduction of the bacterial inoculum; however, none of the sterilizers could effect a 6-log reduction in the presence of 10% serum and 0.65% salt. The researchers commented that the inability of sterilizers to reliably eliminate microorganisms in narrow channels in the presence of serum and salt raises concerns about the practice of using ethylene oxide sterilization as a mechanism for controlling outbreaks related to contaminated flexible endoscopes. Bile salts are the major organic component in bile whose function is to emulsify fats and facilitate intestinal absorption.177
In a second, similar study, Alfa et al178 compared the ability of a liquid chemical sterilant and ethylene oxide to sterilize long, narrow lumens. The researchers found that the liquid chemical sterilant achieved a 6-log reduction in bacterial load compared with a 2.5- to 6-log reduction for ethylene oxide. The researchers noted that residual salt appeared to be a major problem for ethylene oxide sterilization, and this raised questions about the practice of using ethylene oxide to sterilize flexible endoscopes used in procedures where there might be residual protein, serum, blood, or salt remaining in the lumen. These data support the need to ensure effective cleaning of narrow lumens before initiating any HLD or sterilization method.
In a quasi-experimental study to assess cleaning and sterilization efficacy in narrow-lumened devices using artificial test soil and to assess the use of artificial test soil as a worst-case organic challenge to the microbial killing efficacy of various sterilization methods, Alfa et al179 inoculated the biopsy channel of a flexible endoscope with artificial test soil containing 108 CFU/mL of Geobacillus stearothermophilus, M chelonae, and E faecalis. Suboptimal cleaning (ie, no brushing, no immersion, only flushing) was compared to optimal manual cleaning (ie, brushing, flushing, immersion) for organic soil removal. The sterilization efficacy of pre-vacuum steam, 100% ethylene oxide, and peracetic acid was evaluated in the presence of this organic challenge. The researchers found that suboptimal cleaning resulted in less than 99% removal of hemoglobin, carbohydrate, and endotoxin, whereas optimal cleaning resulted in greater than 99% removal. The survival of G stearothermophilus and E faecalis in lumens after sterilization suggested that high residual soil loads affect the efficacy of the sterilization process.
VIII.b. After manual cleaning and inspection and when compatible with the endoscope manufacturer’s IFU, flexible endoscopes and accessories should be either mechanically cleaned and mechanically processed by exposure to a high-level disinfectant or a liquid chemical sterilant or should be mechanically cleaned and sterilized. [1: Strong Evidence]
Mechanical processing includes mechanical cleaning, mechanical HLD or sterilization, and mechanical rinsing. The collective evidence shows that mechanical processing improves cleaning effectiveness, increases efficiency, minimizes personnel exposure to biohazardous materials, and can be more successfully monitored for quality and consistency.1,12,15,16,18,22,45,83,85,93,114,122,180–183
Although mechanical processing is more effective than manual processing, recommendations from professional organizations supporting mechanical processing are inconsistent. Some experts93,105,120,182 and clinical practice guidelines13,17–22,122 recommend using only mechanical processing, while other experts89 and clinical practice guidelines15,16,27,44,83,84 support the use of manual methods.
Unless the manufacturer of the mechanical processor has validated the processor to exclude manual cleaning, mechanical processing does not eliminate the need for manual cleaning.122 The sequence of manual cleaning followed by mechanical cleaning most effectively removes bioburden and helps prevent the buildup of dead microorganisms that may occur when incompletely cleaned devices are subjected to HLD or sterilization.120 The physical force of the water pressure used by mechanical processors to flush endoscope channels allows the bioburden to be physically lifted and removed by the flow of fluid.120,182,184
In a quasi-experimental study to evaluate the effectiveness of five methods of HLD for removal of biofilm in endoscopes, Balsamo et al185 used Teflon tubes to simulate the channels of flexible endoscopes. The researchers contaminated the tubes with P aeruginosa biofilm and subjected them to one of five processing methods:
○ manual processing using 2% glutaraldehyde,
○ mechanical processing using 2% glutaraldehyde,
○ manual processing using 0.09% to 0.15% active peracetic acid,
○ mechanical processing using 35% peracetic acid, or
○ mechanical processing using acidic electrolytic water.
The researchers found that none of the processing methods completely removed the biofilm. Mechanical processing using 2% glutaraldehyde or 35% peracetic acid were the most effective in removing the biofilm. The biofilm remained attached to 35.7% of the sample segments (15 of 42) and was completely removed in 26% of the sample segments (11 of 42). There was a statistically significant difference between manual and mechanical processing methods.
Ubhayawardana et al182 conducted a nonexperimental study to evaluate the effectiveness of manual processing for removal of bioburden from side-view endoscopes used for ERCP procedures in a tertiary referral endotherapy unit in Sri Lanka. The researchers obtained samples from 102 different flexible side-view endoscopes before and after processing and then tested them for microbial growth. The researchers found that despite strict adherence to recommended processing protocols, the average culture-positive rates from the endoscope tips was 90% (92 of 102) before processing and 21% (21 of 102) after processing. The culture-positive rate from the working channel after processing was 10% (10 of 102). Notably, manual processing was completed in the procedure room, and this may have contributed to the high culture-positive rate. Klebsiella and Candida species were the most common microorganisms found. The results of this study suggest that processing of the endoscope tip was less effective than processing of the working channels. The researchers concluded that there was a high culture-positive rate after manual processing of side-view endoscopes.
Some mechanical processors also provide a thermal or chemical decontamination process that removes or reduces the number of microorganisms or infectious agents and renders reusable medical devices safe for use, handling, or disposal.12,45,58,90
In addition to improved cleaning and decontamination, mechanical processors may also provide improved rinsing of disinfectants and reduce the potential for patient injury associated with residual disinfectants remaining in the endoscope. In a nonexperimental laboratory study, Farina et al186 determined residual levels of glutaraldehyde in two gastroscopes and two colonoscopes following manual and automatic disinfection procedures. The researchers found that residual glutaraldehyde levels were much higher after manual disinfection (< 0.2 to 159.5 mg/L) than after mechanical disinfection (< 0.2 to 6.3 mg/L).
Mechanical processors may reduce the risk of cross contamination from one load to another by allowing for single-use cleaning and disinfecting solutions.122
Using mechanical processors reduces the potential for breaches in recommended processing protocols associated with human error and noncompliance.67,122,139,182 Audits have shown that personnel do not consistently adhere to guidelines for processing, and this has led to outbreaks of infection.15,45 Procedures for manual processing of flexible endoscopes may be inadequate or inconsistent and may vary significantly from one health care facility to another, as well as within the same facility.89,180
Ofstead et al181 conducted a prospective multisite observational study to evaluate procedures, employee perceptions, and occupational health issues related to processing flexible endoscopes. The researchers collected data from two gastroenterology specialty centers, two multispecialty hospitals, and one outpatient surgery center from five geographically diverse regions in the United States. The researchers found that when performing manual processing, personnel performed all required steps for only one of 69 endoscopes processed (1.4%). When performing mechanical processing, personnel performed all required steps for 86 of 114 endoscopes processed (75.4%). Steps commonly omitted during manual processing included brushing, forced-air drying, and flushing with 70% isopropyl alcohol. The only step routinely omitted during mechanical processing was the final external drying of the endoscope after removal from the processor.
In an examination of the peer-reviewed and non-peer-reviewed literature to identify lapses in processing flexible endoscopes reported in North America from 2005 to 2012, Dirlam Langlay et al187 found that lapses occurred in various types of facilities and in all major steps of processing. Lapses included failing to
○ comply with established guidelines,
○ preclean endoscopes before processing,
○ correctly contain contaminated endoscopes,
○ adequately brush endoscope channels,
○ adequately clean the elevator channel of duodenoscopes,
○ perform adequate HLD,
○ correctly program mechanical processors,
○ report malfunctioning mechanical processors, and
○ document processing personnel competency.
These lapses may have resulted in patient exposure to potentially contaminated gastrointestinal endoscopes.
In a study to determine common practices for endoscope processing at regional endoscopy centers, Moses and Lee188 sent anonymous questionnaires to 367 members of the Society of Gastroenterology Nurses and Associates (SGNA) in Pennsylvania, Delaware, Virginia, Maryland, and the District of Columbia. The survey was completed by 230 members (63%), the majority of whom (59%; n = 136) practiced in hospital-based endoscopy units performing more than 3,000 procedures a year. The results of the study showed wide variation in the manual cleaning process. Only 70% (n = 161) suctioned cleaning solution through the endoscope channels and also brushed channels and valves. There was variation in the number of times the channels were brushed, with the majority (37%; n = 85) brushing three to five times. In 6% of the units (n = 14), manual cleaning was the only processing step, and 18% (n = 42) reported omitting manual cleaning before mechanical processing.
Surveyors from the Centers for Medicare & Medicaid Services189 assessed adherence to infection control practices in 68 ambulatory surgery centers in three states (ie, 32 in Maryland, 16 in North Carolina, 20 in Oklahoma). The surveyors assessed compliance with hand hygiene, injection safety and medication handling, equipment processing, environmental cleaning, and handling of blood glucose monitoring equipment. They found that overall, 46 (67.6%) of the surgery centers had at least one lapse in infection control, and 12 (17.6%) had identified lapses in three or more infection control categories. Errors in processing included failing to adequately clean instruments before sterilization or HLD (four of 60; 6.7%); failing to use chemical or biologic indicators in sterilizer loads (two of 55; 3.6%); failing to prepare, test, or replace high-level disinfectants (eight of 48; 16.7%); failing to document HLD or sterilization (two of 66; 3%); failing to store sterilized or disinfected equipment in a clean area (one of 65; 1.5%); and reprocessing single-use devices (four of 10; 40%).
Although mechanical processors provide many advantages compared with manual processing, there are some disadvantages. Mechanical processors require preventive maintenance to ensure safe and effective operation.122,180 The use of contaminated or defective mechanical processors for cleaning, disinfecting, or rinsing can result in inadequate processing22,122,183 that has been associated with outbreaks of endoscopy-related infections and pseudo-infections100,208–219 and patient injury.220,221 In addition, the presence of biofilm has been detected in mechanical processors.208,209
An Endoscope Task Force was established to review endoscope processing incidents in England from 2003 to 2004 and to make recommendations to prevent recurrences. The task force found there were a total of 18 incidents. Eight of the incidents (44%) involved failures to adequately clean endoscope channels. Seven incidents (39%) involved problems with mechanical processors. In one incident, a pump had failed, and due to the lack of a functional alarm system, the failure to irrigate endoscopes with cleaning solution and disinfectant was not being signaled. Another incident involved a malfunction in which the cleaning solution was frothing excessively. The cause was identified as a faulty valve; however, processing personnel had removed the pressure sensors and alarm systems from the machine to stop the signal when it was incorrectly deemed that there was nothing wrong. An additional incident involved an incorrect adaptor. Three incidents involved the incorrect use of cleaning solutions.222
Vanhems et al223,224 described the possible transmission of pathogens to 236 persons exposed to an endoscope processed in a defective mechanical processor in a gastrointestinal endoscopy unit. In March 2002, a nurse from the digestive diseases unit questioned the “tactile sensation” of the gastrointestinal endoscopes after they had been mechanically processed. The manufacturer was contacted and determined that the pump for injecting disinfectants into the biopsy channels was malfunctioning and the alarm system designed to detect such a flaw was also malfunctioning. The endoscopes had not been disinfected, and patients had potentially been exposed to contaminants. Notably, the endoscopes had been manually cleaned before being placed into the mechanical processor. A total of 197 (83.5%) patients found to be at risk for infection completed follow-up. No acute infection was observed. The investigators noted that the problem was identified because of the subjective perception of an experienced nurse.
The time required for mechanical processing may be longer180 or shorter225 than the time required for manual processing, and costs may be increased180 or offset by financial gains as a result of increased productivity.226 The consistency of mechanical processing also may minimize the potential for damage and the need for repairs.67
Alfa et al225 compared the efficacy of the cleaning phase of a mechanical processor with optimal manual cleaning in a quasi-experimental laboratory study. A bronchoscope, gastroscope, and colonoscope were each inoculated with artificial test soil containing P aeruginosa and E faecalis and then allowed to dry for one hour. The endoscopes were either manually cleaned following the endoscope manufacturer’s IFU or mechanically processed following the IFU for the processor. The results showed a greater than 90% reduction in soil levels for both manual and mechanical cleaning. Manual cleaning was slightly better for exterior surfaces, and mechanical cleaning was slightly better for removal of microorganisms from the channels. The researchers noted that manual cleaning time varied between 15 to 25 minutes per endoscope, depending on the type of endoscope being cleaned. This was substantially longer than the six to seven minutes of cleaning time required for mechanical cleaning of endoscopes.
Forte and Shum227 used a time and motion study to compare the costs of personnel resources and consumable supplies associated with mechanical processors that do and do not require manual cleaning before processing. For three days, the researchers timed and observed two technicians who performed all endoscope processing activities. The researchers found that the total time to process endoscopes was significantly shorter when the technicians used the processor that did not require manual cleaning. The difference in median time to process was 12.6 minutes per colonoscope, 6.31 minutes per gastroscope, and 5.66 minutes per bronchoscope. The amount of time saved per day was 6.2 hours. The researchers determined that the cost of consumable supplies was slightly higher per processing with use of the processor that did not require manual cleaning ($8.91 [$9.50 in 2015 US dollars]) compared with use of the processor that did require manual cleaning ($8.31 [$8.86 in 2015 US dollars]).
Funk and Reaven226 used data from peer-reviewed published literature and country-specific market research to compare manual processing to mechanical processing relative to productivity, need for endoscope repair, and infection transmission in India, China, and Russia. The researchers found that conversion to mechanical processing had a positive effect on financial performance, paying back the capital investment within 14 months in China and within seven months in Russia. In India, the additional revenue generated by the change to mechanical processing offset nearly all of the operating costs.
VIII.b.1. After precleaning and leak testing, and when directed by the mechanical processor manufacturer’s IFU, mechanical processing may be accomplished without manual cleaning. [2: High Evidence]
The mechanical processor manufacturer has validated the processes required for effective processing without manual cleaning.90
In a quasi-experimental laboratory study to assess the efficacy of a mechanical processor that did not require manual cleaning before use, Alfa et al228 evaluated patient-used duodenoscopes (n = 15), bronchoscopes (n = 10), colonoscopes (n = 15), and gastroscopes (n = 15). The endoscopes had been precleaned at the point of use and mechanically processed without additional manual cleaning before processing. All endoscope channels and two external surface sites were sampled to determine residual organic and microbial load. The results of the study showed that 99.7% of lumens and 98.8% of surfaces met or surpassed the predetermined cleaning endpoints for protein (< 6.4 µg/cm2) and bioburden (< 4-log10 viable bacteria/cm2) residuals.
The researchers also conducted simulated use testing by inoculating the channels and two surface sites of bronchoscopes (n = 3), colonoscopes (n = 3), and duodenoscopes (n = 3) with artificial test soil containing 108 CFU/mL of E faecalis, P aeruginosa, and C albicans. The endoscopes were allowed to dry for one hour before sampling. The results showed that 100% of both lumens and surface sites met or surpassed the cleaning end points for protein and bioburden residuals.228
VIII.c. Mechanical processing should be performed in accordance with the endoscope manufacturer’s IFU and the mechanical processor manufacturer’s IFU.17 [3: Moderate Evidence]
There are multiple types of flexible endoscopes and mechanical processors. Instructions for use may vary among manufacturers. Even slight deviations from the recommended protocols can lead to the survival of microorganisms and an increased risk for infection.225 Kressel and Kidd208 reported a pseudo-outbreak of M chelonae and Methylobacterium mesophilicum caused by a contaminated mechanical processor in an academic medical center between July 1998 and October 1998. An unusual number of fungal cultures obtained during bronchoscopy procedures (26 of 131; 20%) grew M chelonae. The 26 cultures came from 22 patients; however, none of the patients had clinical evidence of pulmonary mycobacterial infection.
The investigators sampled the bronchoscopes, the mechanical processors, and the glutaraldehyde from the mechanical processors, and obtained positive results for M chelonae. They discovered that because of time constraints, employees had modified the connections required for the alcohol flush, rendering it inadequate. As a result, the mechanical processors became contaminated with biofilm that could not be removed. The processors then contaminated the bronchoscopes. The outbreak ended when the facility purchased a new mechanical processor.208
Compatibility between the endoscope and the mechanical processor is necessary to ensure effective processing of the endoscope and to prevent patient infection.180
Larson et al219 investigated a potential outbreak of tuberculosis in a community hospital in New York in October 2000. Three patients had bronchoscopy specimen cultures that were positive for M tuberculosis; however, only one patient had clinical signs and symptoms consistent with tuberculosis. The three culture-positive specimens of M tuberculosis were obtained within nine days of each other from the same bronchoscope. A review of the processing procedures showed that the mechanical processor was not approved for use with the bronchoscope by the bronchoscope manufacturer.
VIII.c.2. Flexible endoscopes and accessories should be positioned within the mechanical processor in a manner that ensures contact of the processing solutions with all surfaces of the endoscope. [4: Limited Evidence]
Contact of all surfaces of the endoscope with processing solutions is necessary to achieve effective processing.
The complexity of flexible endoscopes and the variety of processing equipment available make it essential to follow the manufacturers’ IFU to achieve optimal processing.
In a nonexperimental study to determine whether the noncritical portions of a flexible laryngoscope could harbor microorganisms, Bhatt et al229 randomly sampled six flexible laryngoscopes from the eyepiece and handle immediately before use and after subsequent HLD wherein only the shaft of the endoscope was immersed in the high-level disinfectant. The researchers found there was bacterial growth in 41% (seven of 17) of samples. The results of the study demonstrate that despite HLD of the endoscope shaft, the noncritical portions of the endoscope can harbor microorganisms, and complete submersion of the endoscope is necessary to achieve complete processing.
Mechanical processors may require that endoscope channels be fitted with flow restrictors or tubing connectors to regulate fluid outflow.225 The restrictors and tubing direct fluids into specific channels, thereby ensuring perfusion of the channels with necessary fluid flow dynamics.225 Because of the complexity of the channels and their internal connections, it is critical that the correct connection tubing and flow restrictors be used to achieve adequate flow dynamics.225 Flow restrictors and tubing connectors are often specific to the make and model of the flexible endoscope.225
The CDC212 reported three clusters of culture-positive bronchoscopy specimens obtained from patients at local health care facilities in New York between 1996 and 1998. The first cluster involved five patients at a health care facility whose bronchial specimens yielded M tuberculosis with the same genetic pattern, suggestive of a common source. Samples taken from the bronchoscopes used during the procedures were negative. The investigators identified an inconsistency between the processing procedures recommended in the manufacturer’s IFU and those followed by processing personnel. The biopsy port cap was not replaced before the bronchoscope was placed into the mechanical processor, and this led to a 50% reduction in flow and a 25% reduction in pressure, resulting in processing failure.
The second cluster involved bronchial specimens that were culture-positive for Mycobacterium avium-intracellulare from seven patients who had all undergone bronchoscopy with the same bronchoscope. The investigators found that the bronchoscope was being processed in a mechanical processor using the connectors provided by the bronchoscope manufacturer rather than the connectors recommended by the mechanical processor manufacturer.212
The third cluster involved 18 patients at a health care facility who had bronchial specimens that grew imipenem-resistant P aeruginosa (IRPA). None of the patients had IRPA isolated from sputum samples obtained before bronchoscopy, and all but one isolate had identical genetic patterns. The investigators found that the bronchoscopes were not being connected to the mechanical processor in accordance with the mechanical processor manufacturer’s IFU.212 The investigators concluded that there was a need for processing personnel to review and adhere to manufacturer’s IFU and ensure correct connections between the endoscope and the mechanical processor.
Sorin et al230 reported 18 isolates of IRPA from 18 patients who underwent bronchoscopy procedures during a three-month period immediately after implementation of a new mechanical processor. Three patients demonstrated clinical signs and symptoms of infection and were treated with antibiotics. A representative of the mechanical processor manufacturer noted several incorrect connections from the bronchoscope to the processor. The investigators concluded that the incorrect connections led to an insufficient flow of the chemical sterilant through the bronchoscope lumen, resulting in incomplete processing of the bronchoscope.
VIII.c.4. Processing personnel should monitor mechanical processing cycles to verify they are completed as programmed. If a mechanical processing cycle is interrupted, the entire cycle should be repeated.16,17,20,21,44,83 [1: Strong Evidence]
VIII.d. Mechanical processing of flexible endoscopes should be performed using critical water.119 [4: Limited Evidence]
Critical water meets the following parameters:
○ hardness: < 1 mg/L calcium carbonate,119
○ pH: 5 to 7,119
○ chloride: < 1 mg/L,119
○ bacteria: < 10 CFU/mL,119 and
○ endotoxin: < 10 endotoxin units (EU)/mL.119
Water quality is affected by the presence of dissolved minerals, solids, chlorides, and other impurities and by its acidity and alkalinity.119 Untreated water quality fluctuates over time, varies with geographic location and season, and can affect the outcome of cleaning actions.119
Hard water can decrease the effectiveness of cleaning solutions and disinfectants, and can also adversely affect the performance of mechanical processors.119 Deposits can form on medical devices that may prevent microorganisms and organic material from being removed during cleaning.119 Hard water may be incompatible with some high-level disinfectants and liquid chemical sterilants.119
Water with pH levels that are acidic or alkaline may affect the performance of cleaning solutions (especially enzymatic cleaning solutions), disinfectants, or sterilants.119
Controlling bacterial and endotoxin levels in water used for processing flexible endoscopes helps reduce the risk for patient infection.119
VIII.e. Mechanical processing should be performed using cleaning, disinfectant, and sterilant solutions and chemicals recommended by the endoscope manufacturer and the mechanical processor manufacturer.13,18,20,22,44,45,46,83,84 [1: Strong Evidence]
There are multiple types of endoscopes and mechanical processors. Recommended cleaning and disinfectant or sterilant solutions may vary among manufacturers.
The chemical actions of cleaning, disinfectant, and sterilant solutions vary and are intended for different applications. Following the manufacturers’ IFU decreases the possibility of selecting and using solutions that may damage the endoscope or mechanical processor.44,45
VIII.e.1. Chemicals and solutions used in the mechanical processor should be used at the concentration, volume, temperature, and contact time recommended by the mechanical processor manufacturer.13,18–20,40,43,44,69
If recommended by the mechanical processor manufacturer, a test strip or other FDA-cleared testing device specific for the disinfectant and minimum effective concentration of the active ingredient should be used for monitoring solution potency.1,40,43
[1: Strong Evidence]
Some mechanical processors may require the use of a test strip or device to verify efficacy of the high-level disinfectant or liquid chemical sterilant used for processing.40 The concentration of a high-level disinfectant or liquid chemical sterilant will decrease with dilution by water, the presence of organic material, evaporation of the solution, and exposure of the solution to light.40 Checking the concentration of the high-level disinfectant or liquid chemical sterilant before use reduces the risk of inadequate processing.40 High-level disinfection solution potency cannot be guaranteed when the solution falls below the minimum effective concentration. Incorrect dilution, volume, temperature, or contact time may result in a processing failure.40,69,93,131
VIII.e.2. Chemicals and solutions used for cleaning and processing flexible endoscopes and endoscope accessories must be handled in accordance with local, state, and federal regulations and the manufacturer’s IFU.38
The safety data sheets must be readily accessible to employees within the workplace.38
Chemical spill kits must be stored in close proximity to areas where chemicals or other hazardous materials are stored.38
[1: Regulatory Requirement]
Cleaning products, high-level disinfectants, and liquid chemical sterilants can be hazardous to the individuals who are using them. It is a regulatory requirement that employers have a program to ensure that information about the identification, hazards, composition, safe handling practices, and emergency control measures of a chemical is readily available to employees.38 When employees have information about the chemicals being used, they can take steps to reduce exposure, establish safe work practices, and implement first aid measures when necessary. Chemical spill kits enable prompt response by providing items that may be required in the cleanup of spills, leaks, or other discharges of hazardous materials.
VIII.e.3. The following products should not be used for processing flexible endoscopes:
[1: Strong Evidence]
Skin antiseptics (eg, povidone-iodine, chlorhexidine gluconate) are not formulated as disinfectants.1 Hypochlorites (eg, bleach) are corrosive and may be inactivated by organic material.1,45 Phenolics (eg, orthobenzyl-para-chlorophenol) may cause tissue irritation and injury to mucous membranes.1,45 Quaternary ammonium compounds (eg, benzalkonium chloride) do not provide adequate disinfection of flexible endoscopes.1,45
Esteban et al231 reported a pseudo-outbreak of 15 Aeromonas hydrophila isolates from colon biopsies between January 1998 and May 1998. The investigators found that the endoscopes had been manually cleaned with an enzymatic cleaning solution and rinsed with utility water and then placed into a quaternary ammonium solution for 20 minutes. The pseudo-outbreak ended when the quaternary ammonium solution was replaced with 2% glutaraldehyde for HLD.
VIII.f. Following disinfection, the endoscope and endoscope channels should be mechanically rinsed and flushed with critical or sterile water.1,15,19,20,22,44,83,89,93 Endoscope accessories and removable parts should be rinsed with critical or sterile water. [1: Strong Evidence]
Thorough rinsing and flushing with critical water helps prevent patient injury associated with disinfectant or sterilant retained in the endoscope.1,45,186,232–240 Utility water may contain microorganisms and endotoxins that can be deposited on the endoscope during the final rinse.1,119 Tissue contaminated with endotoxins can cause severe inflammation.119 Outbreaks of endoscopy-related infections and pseudoinfections have been linked to rinsing flexible endoscopes with utility water.49,93,241 Using critical or sterile water reduces the potential for introducing microbes into the endoscope.65
Farina et al186 conducted a nonexperimental study to determine residual levels of 2% glutaraldehyde in flexible endoscopes after manual and mechanical HLD. In a total of 92 measurements taken after manual HLD (n = 24) and mechanical HLD (n = 68) for two gastroscopes and two colonoscopes, the researchers found that residual levels of glutaraldehyde were higher and more variable after manual HLD (< 0.2 mg/mL to 159.5 mg/mL) than after mechanical HLD (< 0.2 mg/mL to 6.3 mg/mL). The researchers concluded that residual 2% glutaraldehyde levels (especially after manual disinfection) could be high enough to be toxic and a cause of colitis or proctitis following endoscopy.
In an attempt to reduce processing time, Kim and Baek233 changed from using 2% glutaraldehyde to process flexible endoscopes in their endoscopy unit to using a peracetic acid compound. After the change, the researchers observed a series of 12 patients who experienced colonic mucosal pseudolipomatosis. The protocol for mechanical disinfection included a 60-second rinse cycle. The researchers reviewed the processing records and found that the colonic pseudolipomatosis occurred only when one of six nurses was on duty. The nurse sometimes rinsed the endoscopes for only 10 seconds and at other times omitted the mechanical rinsing cycle, opting to manually rinse the endoscopes under running water. No more cases occurred after the 60-second rinse cycle was reinstated. The researchers noted that this case highlighted the importance of completing all processing steps and following the manufacturer’s IFU when using mechanical processors.
Wendleboe et al242 investigated an outbreak of seven P aeruginosa infections associated with outpatient cystoscopy performed by a urologist in New Mexico from January to April 2007. The investigators found multiple breaches in processing procedures including rinsing of the cystoscope in unsterile water after processing. Specifically, sterile water was placed in a container and replaced every two weeks or when it began to smell. The outbreak resolved when improved procedures for processing flexible cystoscopes were implemented.
VIII.g. A multidisciplinary team that includes infection preventionists, endoscopy and perioperative RNs, endoscopy processing personnel, endoscopists, and other involved personnel should conduct a risk assessment to determine whether endoscope lumens should be flushed with 70% to 90% ethyl or isopropyl alcohol. [1: Strong Evidence]
Flushing endoscope lumens with alcohol may not be necessary if the endoscope is effectively dried.243 Because of the fixative properties of alcohol, this practice is not recommended in some countries.18–20,22,69,93
Alfa and Sitter243 conducted a prospective, quantitative assessment of the effect of drying on the bacterial load in duodenoscopes used for ERCP procedures. The researchers sampled 42 duodenoscopes that had been manually cleaned and then mechanically processed at two, 24, and 48 hours after disinfection. They found that 21 duodenoscopes (50%) were contaminated. There was visible moisture remaining in the suction channel even though processing personnel had followed the mechanical processor manufacturer’s IFU. The bacterial counts ranged from 1 × 101 CFU/mL−1 to 1 × 107 CFU/mL−1. The researchers added 10 minutes of drying time to 19 of the 21 contaminated duodenoscopes, either by purging the lumens of the endoscopes with instrument air or by adding 10 minutes of drying time in the mechanical processor. The results showed that there were no microorganisms detected after the additional drying time. The researchers concluded that the additional 10 minutes of drying time prevented bacterial growth in the endoscopes and eliminated the need for an alcohol flush.
Many clinical practice guidelines1,15,16,19,44–46,83 and experts in the field89,93,244 recommend manual or mechanical flushing of endoscope lumens with alcohol because it facilitates drying of the endoscope lumens by binding with residual water and enhancing evaporation.1,16,65 Alcohol prevents colonization and transmission of waterborne bacteria.46,65,89 Some mechanical processors automatically flush the endoscope with 70% isopropyl alcohol, others do not.
Wang et al245 reported a pseudo-infection of M chelonae involving 25 patients with 25 positive isolates (ie, 18 bronchial, one soft tissue, one plural, five corneal) between September 1992 and December 1992. The investigators found the suction channels of four different bronchoscopes to be the sources of contamination and noted that the processing procedure did not include flushing the suction channels with 70% isopropyl alcohol. The bronchoscope processing procedures were modified to include flushing the endoscope lumens with 70% isopropyl alcohol after mechanical processing, and no further episodes of cross contamination or infection occurred.
In a quasi-experimental study to analyze whether flushing endoscope lumens with 70% ethyl alcohol after processing reduced the risk of microbiological contamination, Gavalda et al246 sampled 18 different bronchoscopes after processing. The samples were collected on a monthly basis during a four-year period. Nine of the bronchoscopes were processed manually, and nine were processed mechanically. A total of 620 samples was obtained. The researchers found that 564 samples (91%) tested negative, and 56 samples (9%) tested positive, of which two (3.3%) contained pathogenic microorganisms. Only one positive sample (0.6%) was detected among the 167 samples from endoscopes flushed with alcohol after disinfection. The researchers recommended flushing bronchoscope channels with 70% ethyl alcohol after each disinfection cycle.
○ Removable parts and endoscope accessories should be dried.16
[1: Strong Evidence]
Some mechanical processors have drying systems, others do not.
The collective evidence shows that effectively drying the internal and external surfaces of the endoscope is as important as effective cleaning and disinfection or sterilization.244 The long, narrow channels of the endoscope make it difficult to verify thorough drying.157 Any moisture remaining on the exterior and interior surfaces of the endoscope can facilitate microbial growth and biofilm formation during storage.19,46,65,93,131 Because bacteria can double in population every 20 to 30 minutes, an inadequately dried endoscope contaminated with only one or two viable bacteria can, after eight hours of storage, be contaminated with tens of thousands of bacteria.247 These multiplying bacteria could pose a risk for infection.247
In a nonexperimental study to mimic disinfection and drying of biofilm in contaminated endoscopes, Kovaleva et al248 prepared single species biofilm (ie, C albicans, Candida parapsilosis, P aeruginosa, or S maltophilia) and dual species biofilm (ie, C parapsilosis with P aeruginosa or C parapsilosis with S maltophilia) in sterile tissue culture plates and treated the single and dual strains with 1% peracetic acid. The culture plates were incubated at 122° F (50° C) for two hours to mimic the drying process, and then sealed and incubated at room temperature (ie, 68° F to 72° F [20° C to 22° C]), for one, three, and five days to mimic the storage process. The researchers found that there was no biofilm regrowth when the drying process was applied, but regrowth of all biofilms occurred when the drying process was not implemented. The researchers concluded that thorough drying was an important factor in the maintenance of bacteria-free endoscopes.
In a nonexperimental study, Ren-Pei et al96 investigated biofilm on endoscope channels. The researchers collected 66 endoscope suction and biopsy channels and 13 water and air channels from 66 endoscopy centers in hospitals throughout China and used SEM to examine biofilm on the inner surface of the channels. A total of 36 suction and biopsy channels (54.5%) and 10 water and air channels (76.9%) were found to have biofilm.
After examining the endoscope channels, the researchers sent a questionnaire to each of the 66 endoscopy centers to explore the correlation between endoscope processing procedures and the amount of biofilm found in the endoscope channels. They divided the responses (N = 66) into hospitals without biofilm on endoscopes (Group A; n = 30), and hospitals with biofilm on endoscopes (Group B; n = 36). The researchers found that the proportion of endoscopy centers using an alcohol flush and compressed air drying in Group A was 76.6% (23 of 30) compared with 38.9% (14 of 36) in Group B. The researchers concluded that the formation of biofilm on the endoscope channels could be related to inadequate drying.96
Purging the endoscope channels with instrument air or using a mechanical drying system facilitates drying without introducing contaminants into the clean device, removes residual alcohol, and reduces the likelihood of contamination of the endoscope by waterborne pathogens and the transmission of pathogens that may result in patient infection.1,22,44,45,89,99,157
Bajolet et al118 reported transmission of an extended-spectrum ß-lactamase-producing P aeruginosa in four patients who underwent an EGD procedure with the same gastroscope between May and August 2011. The gastroscope had been purchased in January 2011. Microbiological sampling before its first use showed negative results. The investigators observed processing procedures and found the endoscopes were still wet at the end of the cleaning process and were not adequately dried before storage. They concluded that the moist environment in the channels of the endoscope had supported development of a persistent biofilm that contributed to transmission of a serious infection.
Hagan et al249 reported a pseudo-infection of Rhodotorula rubra related to a contaminated bronchoscope in a Kansas City medical center. Between October and November 1992, bronchoscopy specimens from 11 patients yielded growth of R rubra. The outbreak ended when investigators initiated changes to the processing procedures that included adding an alcohol flush and purging the lumens of the bronchoscope with air for three minutes.
Carbonne et al250 reported an outbreak of K pneumoniae carbapenemase-producing K pneumoniae type 2 that was detected in two hospitals in France during September 2009. Of the 13 patients, seven had been examined with the same duodenoscope that had been used to examine the source patient. The investigators found that the cleaning and disinfection processes were consistent with French national guidelines; however, the drying process was not optimal. The procedures were revised to include a systematic drying step after each disinfection cycle, and no additional cases were identified.
Because of a severe outbreak of K pneumoniae producing extended-spectrum ß-lactamase that occurred in 16 patients undergoing ERCP procedures in a hospital in France between December 2008 and August 2009, Aumeran et al55 observed the duodenoscope processing procedures. They found that the duodenoscopes were not fully dried before they were stored. The investigators hypothesized that bacteria were introduced into the channels of the duodenoscope during the procedures, and despite repeated cleaning and disinfection, the contamination persisted because the moisture remaining in the endoscope channels created conditions favorable to the persistence and growth of the involved organism. The infection was transmitted to 12 patients. Implementing adequate drying of the endoscopes and ensuring that the elevator channel was dry before storage led to an abrupt termination of the outbreak.
VIII.i. A multidisciplinary team that includes infection preventionists, endoscopy and perioperative RNs, endoscopy processing personnel, endoscopists, and other involved personnel should conduct a risk assessment to determine the potential harms compared with the benefits of initiating one or more enhanced methods for processing duodenoscopes.138 [3: Moderate Evidence]
Initiating enhanced processing methods for duodenoscopes may decrease the potential for pathogenic microorganisms to remain on the endoscope after processing.138,165,251 Before processing, gastrointestinal endoscopes carry a microbial load of approximately 107 to 10 10 (ie, 10,000,000 to 10,000,000,000) organisms.112,113,115,252 Cleaning results in a 2-log to 6-log reduction.253,254 High-level disinfection results in a 4-log to 6-log reduction.254
Theoretically, if a flexible endoscope carried a microbial load of 1010, and cleaning reduced the microbial load by 2-log (10−2), and this was followed by HLD that resulted in a 4-log reduction (10−4), the device would still have a 4-log (104) microbial load after processing (ie, 10,000 microorganisms). Repeat HLD or sterilization would increase the margin of safety and further decrease the number of pathogenic microorganisms remaining on the endoscope.165,251
VIII.i.1. Enhanced methods for processing flexible duodenoscopes may include implementing HLD followed by
[3: Moderate Evidence]
Culturing duodenoscopes after every processing cycle and quarantining the endoscope until culture results are known may be an effective method for assessing processing effectiveness.
Ross et al144 implemented a process for quarantining flexible duodenoscopes following an outbreak of multidrug-resistant E coli that occurred in a Seattle medical center between November 2012 and August 2013. Thirty-two patients were found to harbor one of two genetically similar strains of the organism. All of the patients had undergone ERCP procedures. The investigators were unable to find any lapses in HLD or infection control procedures. The genetic strain of E coli was identified by culture on four of eight duodenoscopes, three of which required critical repairs despite a lack of noticeable malfunction. Twenty new duodenoscopes were purchased to implement the quarantine process.
After mechanical processing performed in accordance with the manufacturer’s IFU, cultures were taken of the duodenoscope, mechanical processing was repeated after culturing, and the duodenoscope was hung vertically in a storage cabinet with passive airflow for 48 hours. If the culture report was negative, the endoscope was released for use. If bacterial pathogens were identified, the duodenoscope was reprocessed, cultured, and quarantined for an additional 48 hours and only released if the cultures were negative. During a one-year period, a total of 1,524 cultures were collected from the duodenoscopes, of which 200 (13.1%) were positive for bacterial growth. The majority, 171 (85.5%) grew common skin flora and nonpathogenic organisms. The remaining 29 (14.5%) were positive for pathogenic bacterial growth. In two cases, the duodenoscopes required more than one repeat cycle of HLD in order to be culture-negative. The two endoscopes were returned to the manufacturer for inspection, and one had to be taken out of service. The investigators concluded that the quarantine process was successful in ending the outbreak of duodenoscope-related infections.
Because some duodenoscopes may have persistent microbial contamination despite HLD, repeat HLD or sterilization may provide a greater margin of safety.138 Using a liquid chemical sterilant system after HLD may provide a greater margin of safety and may be effective for heat-sensitive devices such as flexible endoscopes; however, because this process may require rinsing with unsterile water after sterilization, the endoscope may not remain completely free of all viable microorganisms.138
Ethylene oxide sterilization following HLD may also provide a greater margin of safety, and may be effective for heat-sensitive devices such as flexible endoscopes; however, it can fail in the presence of organic material, it is costly and not accessible to all health care facilities, and it may affect the material and mechanical properties of the duodenoscope.138
Performing HLD followed by HLD, liquid chemical sterilization, low-temperature sterilization, or ethylene oxide sterilization has not been validated by the endoscope, mechanical processor, or sterilizer manufacturers, and further research is warranted.
VIII.j. Processes and procedures for packaging and sterilizing flexible endoscopes and endoscope accessories should be carried out in accordance with the AORN Guideline for Selection and Use of Packaging Systems for Sterilization255 and the AORN Guideline for Sterilization.256 [1: Strong Evidence]
Sterilization provides the highest level of assurance that processed items are free of viable microbes.45
Packaging systems permit sterilization of the contents within the package, protect the integrity of the sterilized contents, prevent contamination of the contents until the package is opened for use, and permit the aseptic delivery of the contents.255
VIII.k. Precautions to minimize the risk for transmission of prion diseases from flexible endoscopes and endoscope accessories should be carried out in accordance with the AORN Guideline for Cleaning and Care of Surgical Instruments.58 [1: Strong Evidence]
Prions are a unique class of infectious proteins that cause fatal neurological diseases.257 Examples of prion diseases are Gertsmann-Straüssler-Schienker syndrome, fatal familial insomnia syndrome, and Creutzfeldt-Jakob disease (CJD).257 Creutzfeldt-Jakob disease is a rare and ultimately fatal degenerative disease that belongs to a group of neurological disorders known as transmissible spongiform encephalopathies (TSEs).20 Variant Creutzfeldt-Jakob disease is acquired from cattle with bovine spongiform encephalopathy, or “mad cow disease.”46,167,257,258
The collective evidence shows there are concerns about the potential for endoscopic transmission of prions and other TSEs, including CJD, and vCJD.46,122 For an endoscope to act as a vehicle for transmission of prions, contact with infective tissue is required.46,257
In CJD, the prions accumulate in the central nervous system and are transmitted by exposure to infectious brain, pituitary, or eye tissue. Because flexible endoscopes do not come in contact with brain, pituitary, or eye tissue, endoscopic transmission of CJD or other TSEs is unlikely.46,257
In vCJD, the prions accumulate in both central nervous system and lymphoid tissue.167,258 Patients with vCJD have infectivity detectable in the appendix, spleen, tonsils, thymus, and lymph nodes.20,46,93,167,257,258 The prions responsible for vCJD are found in abundance in the Peyer patches located in the terminal ileum.20,167 Aggregates of lymphoid prions are also found in the large intestine and the stomach.167 Transmission of vCJD via a flexible gastrointestinal endoscope is therefore theoretically possible because of the lymphatic distribution of prions. The risk for transmission is greater during invasive interventional procedures (eg, biopsy, polypectomy, mucosal resection, sphincterotomy) than during noninterventional procedures20,258; however, there have been no reports of such transmission described in the literature.93,167,258
VIII.k.1. Flexible endoscopes and accessories used during endoscopy procedures on high-risk patients should be processed as shown in Table 3. [1: Strong Evidence]
Methods for processing instruments contaminated with prions are unsuitable for semicritical, heat-labile devices such as flexible endoscopes.20,257 Current recommendations for processing instruments exposed to prions include decontamination with concentrated sodium hydroxide (ie, lye) or sodium hypochlorite (ie, bleach), which are corrosive to flexible endoscopes, followed by prolonged steam sterilization, which most flexible endoscopes cannot tolerate.93,257 Dry heat, glutaraldehyde, and ethylene oxide are not effective disinfection or sterilization methods for flexible endoscopes contaminated with prions.20,93,258 Aldehyde disinfectants (eg, glutaraldehyde, orthophalaldehyde) may anchor prion proteins within endoscope channels and also render them more difficult to remove. For this reason, aldehyde disinfectants are not recommended for HLD in some countries.20,167,258 Further research is warranted relative to the use of cleaning chemistries and low-temperature sterilization technologies for inactivating prions.257
Discarding the endoscope and accessories after use on high-risk tissue from high-risk patients ensures the endoscope and accessories will not be used on subsequent patients and eliminates the risk of inadequate prion inactivation or patient-to-patient transmission of prion disease.
There is no recommendation for processing critical or semicritical devices contaminated with low-risk tissue from high-risk patients. Although low-risk tissue has been found to transmit CJD, this has been demonstrated only when low-risk tissue has been inoculated into the brain of a susceptible animal.257
Flexible endoscopes contaminated with no-risk tissue do not present a risk for prion transmission.
VIII.l. A multidisciplinary team that includes infection preventionists, endoscopy and perioperative RNs, endoscopy processing personnel, endoscopists, and other involved personnel should conduct a risk assessment to determine whether single-use endoscope sheaths will be used with compatible flexible endoscopes, and if used, whether, and under what circumstances the endoscope will be disinfected using ILD or HLD. [3: Moderate Evidence]
Flexible endoscopes contact mucous membranes and are considered semicritical items requiring a minimum of HLD117,259; however, the collective evidence shows that when compatible with the sheath, and used in accordance with the sheath manufacturer’s IFU, flexible endoscopes may be effectively processed using 70% isopropyl alcohol (an ILD)45 rather than HLD, and processing time is reduced.83,89,260–264
In a quasi-experimental study to compare the efficacy of various high-level disinfectants against mycobacteria when used in combination with manual cleaning, Foliente et al253 found that 70% isopropyl alcohol was as effective against mycobacteria as two high-level disinfectants. The researchers inoculated five colonoscopes and five duodenoscopes with M chelonae. Each endoscope was manually cleaned, and then exposed to one of two high-level disinfectants (ie, 2% glutaraldehyde, 7.5% hydrogen peroxide), 70% isopropyl alcohol, a liquid chemical sterilant (ie, 0.2% peracetic acid), or ethylene oxide sterilization. The researchers sampled the endoscopes after inoculation, manual cleaning, and disinfection or sterilization. The results showed the average number of microorganisms recovered after inoculation was 9.4 × 106 CFU. After manual cleaning, the average number of microorganisms was 9.9 × 103 CFU, reflecting a 3-log reduction. The researchers found no mycobacteria after exposure to ethylene oxide or 0.2% peracetic acid. The average number of microorganisms after exposure to 70% alcohol was 19 CFU/endoscope and after exposure to the high-level disinfectants was 13 CFU/endoscope for 2% glutaraldehyde and 40 CFU/endoscope for 7.5% hydrogen peroxide.
Sheaths reduce but do not eliminate the risk of contamination and do not eliminate the need for manual cleaning of the endoscope after use.89 The endoscope may also be contaminated by the soiled hands or gloves of personnel during application or removal of the sheath.89 The sheath may be breached or may break or tear during use,89 potentially exposing the patient to a flexible endoscope processed by ILD rather than HLD. Sheath failure may not be obvious.259
Lawrentschuk and Chamberlain260 described their experience of using a flexible cystoscope with a single-use endoscope sheath designed to function as a microbial barrier on 200 consecutive patients. The authors found that using the single-use sheath eliminated the need for HLD or sterilization, thus saving time and minimizing personnel exposure to hazardous chemicals. Notably, the sheath failed in 5% of procedures. The authors noted that using the sheath reduced contact of the cystoscope with body fluids and chemicals, and this reduced contact could theoretically prolong the life of the endoscope.
In a nonexperimental study to evaluate the use of endoscope sheaths as barriers to viruses on flexible ear, nose, and throat endoscopes, Baker et al261 challenged the sheaths by applying laser-drilled holes (2 µg to 30 µg) and inoculating the sheaths with suspensions of bacteriophage (1.0 × 108 plaque-forming units (PFU)/mL). The sheath and the endoscope were sampled to recover any virus particles that had penetrated through the holes in the sheath. The researchers found that up to 500 virus particles could pass through the 30 µg holes, indicating a very low viral passage. The researchers concluded that meticulous cleaning of the endoscope followed by ILD provided an instrument that was safe to use on patients.
Elackattu et al262 conducted a quasi-experimental study to evaluate the number of microorganisms on patient-used flexible nasopharyngolaryngoscopes with and without endoscope sheaths. The researchers took samples from multiple sites on 100 flexible nasopharyngolaryngoscopes. The endoscopes were assigned to either the sheath group (n = 50) or the HLD group (n = 50). Samples were taken from the handle of the endoscopes and the lower third of the insertion shaft of the endoscopes before and after use. The results showed that one in 50 endoscope insertion shafts was culture-positive in both groups. There were no positive cultures of handles in the HLD group; however, there were four positive cultures of handles in the sheath group. The sheath method averaged 89 seconds to process, whereas the HLD method averaged 14 minutes. The researchers concluded that using the endoscope sheath reduced processing time and was a safe method for preventing transmission of infection from one patient to the next. Notably, this study was funded by a grant from the sheath manufacturer.
In a randomized controlled trial to investigate the function and processing of flexible gastroscopes, Mayinger et al263 compared the performance of 50 sheathed with 50 unsheathed gastroscopes using a 10-point analog rating scale. The researchers recorded processing times, took samples before and after use and processing, and examined the endoscope sheaths for leaks or tears. The researchers found no leaks or tears in any of the endoscope sheaths. Microbial contamination was found in 10% (five of 50) of the unsheathed endoscopes processed by HLD and in 16% (eight of 50) of the sheathed endoscopes. The processing time for the sheathed system was significantly shorter at 8.9 minutes compared with 48.4 minutes for processing by HLD. Based on the results of the analog rating scale, the endoscopists preferred the unsheathed endoscope, while the processing personnel preferred the sheathed endoscope for its ease of processing.
Alvarado et al264 conducted a randomized controlled trial to determine whether sheathed nasopharyngoscopes could provide reliable protection against bacterial contamination and obviate the need for HLD. The researchers obtained baseline samples at three time periods from the control heads and insertion shafts of three nasopharyngoscopes used in 100 clinical examinations. The samples were obtained
○ before application of the sheath and the procedure,
○ immediately after the procedure and removal of the sheath, and
○ after point-of-use precleaning, disinfection with 70% isopropyl alcohol, and drying.
The researchers found no bacteria on any of the endoscopes after processing. No sheath showed loss of barrier integrity during leak testing. The researchers concluded that after following point-of-use precleaning, disinfection with 70% isopropyl alcohol, and drying processes, the endoscopes were safe to use. This study was funded by a grant from the sheath manufacturer.264
In an evaluation to measure image clarity, ease of use, and handling performance of a flexible bronchoscope and single-use sheath, Colt et al265 measured the performance using a linear rating scale of 1 (poor) to 5 (excellent) after use on 24 patients at three tertiary care centers. The mean performance ratings were > 4.0 for image clarity, illumination, lack of fogging, distal tip angulation, and ease of transnasal passage. All other ratings were > 3.0, with the lowest for handling comfort. The authors concluded that the single-use sheath had the potential to reduce bronchoscope downtime by eliminating the need for HLD between procedures. This study was supported in part by the sheath manufacturer.
Using endoscope sheaths may potentially extend the life of the endoscope83,89,260,266; however, sheaths increase the diameter of the endoscope and this may lead to patient discomfort.266,267 Securely fitted sheaths may also cause damage to the delicate tip of the endoscope when the sheath is removed.266
In a nonexperimental study to evaluate bacterial contamination of flexible cystoscopes protected by single-use sheaths, Jorgensen et al267 leak tested 100 cystoscopes and then sampled the cystoscopes after removal of the sheath and after ILD. The researchers found that all samples had less than 5 CFU/sample. The researchers concluded that processing flexible cystoscopes using ILD was an acceptable alternative to HLD, provided there was a low risk for pathogen transmission. Using the sheath reduced processing time between four and 31 minutes per procedure. The researchers noted that using the sheaths resulted in some reduced visualization for the urologist and increased discomfort for the patient.
Street et al266 audited the costs of disinfection practices in a UK hospital between July 2003 and January 2004 and found that endoscope sheaths had damaged two flexible laryngoscopes with repair costs totaling $15,551.77 (£10,252 [$19,735.77 and £13,029.32 in 2015]). The cause of the damage in one instance was determined to be the sheath being incorrectly fitted, and in the other, the sheath being left on the endoscope overnight. The lining of each flexible endoscope was torn about 2 cm from the tip. Sheaths tightly grip the tip of the flexible endoscope and can shear off the lining of the tip when removed. The authors also opined that the use of sheaths increased patient discomfort and the likelihood of trauma to the nasal mucosa because of the increased diameter of the endoscope, which they calculated to be a 12% increase.
VIII.l.1. Single-use endoscope sheaths should be discarded after each use. [3: Moderate Evidence]
Discarding the endoscope sheath after use helps ensure it is not used on subsequent patients. Brake et al207 conducted a survey of 171 otolaryngologists to compare practices in Canada for disinfection of flexible nasopharyngoscopes. The researchers found that 36.4% of otolaryngologists who used endoscope sheaths were unsure whether the sheaths were to be discarded after use, and 18.2% believed that sheaths were intended to be used multiple times. Only 63.6% always cleaned the nasopharyngoscopes between sheath uses, and 9.1% did not know how often the endoscopes were cleaned between uses. The researchers did not disclose how many of the otolaryngologists who responded to the survey used endoscope sheaths.
VIII.l.2. If approved for ILD by the multidisciplinary team, the endoscope and single-use endoscope sheath should be visually inspected after each use.83 [4: Limited Evidence]
Inspection of the endoscope sheath confirms the integrity of the sheath and may determine the subsequent level of processing (ie, HLD or ILD).83
VIII.l.3. If the sheath is intact, the endoscope may be disinfected by
wiping the external surfaces of the endoscope with 70% isopropyl alcohol83; and
drying the external surfaces of the endoscope with a soft, lint-free cloth or sponge.83
[2: High Evidence]
The manufacturer has validated the sheath to be impermeable to penetration by microorganisms and has validated that sheath application and removal can be accomplished without contamination of the endoscope. The barrier properties of the sheath have been validated, and a minimum of ILD is required before application of a new sheath.268
VIII.l.4. If the endoscope sheath is torn or any portion of the endoscope appears soiled or wet, the endoscope should be cleaned and processed by HLD or sterilization.83 [4: Limited Evidence]
If the endoscope has been contaminated due to a torn sheath, processing by ILD may not be sufficient to prevent patient-to-patient transmission of pathogenic microorganisms, and HLD is required.89
VIII.l.5. If an endoscope is to be used without the sheath for a subsequent patient, it should be processed by HLD or sterilization, even though the sheath appears intact and the endoscope was processed by ILD.12 [5: Benefits Balanced with Harms]
VIII.l.6. If the endoscope is only used with a single-use sheath, the multidisciplinary team, should conduct a risk assessment to establish intervals for leak testing, inspection, and HLD or sterilization. [5: Benefits Balanced with Harms]
VIII.m. A multidisciplinary team that includes infection preventionists, endoscopy and perioperative RNs, endoscopy processing personnel, endoscopists, and other involved personnel should conduct a risk assessment to determine whether chlorine dioxide wipes may be used for disinfection of non-channeled flexible endoscopes when compatible with the endoscope and used in accordance with the disinfectant manufacturer’s IFU. [3: Moderate Evidence]
Chlorine dioxide wipes incorporate a three-step process for cleaning and disinfecting non-channeled flexible endoscopes that includes cleaning, disinfection, and rinsing; however, chlorine dioxide has not been cleared by the FDA as a high-level disinfectant for processing reusable medical equipment.269
Non-channeled flexible endoscopes can become contaminated with mucous, debris, microorganisms, and blood during use.270 Non-channeled flexible endoscopes contact mucous membranes and are considered semicritical items requiring a minimum of HLD.117
Bhattacharyya and Kepnes271 conducted a quasi-experimental study to determine whether HLD rendered non-channeled flexible laryngoscopes free of nonviral infectious microorganisms. The researchers sampled six laryngoscopes after HLD at the beginning, middle, and end of two clinical workdays (n = 36), and after contamination with saliva on two additional days (n = 12). The researchers recovered only one positive culture (2.1%) for mold species. No cultures were positive for bacteria. The researchers concluded that HLD was effective and provided a flexible laryngoscope that was safe for patient use.
Protocols for processing non-channeled flexible endoscopes are derived from protocols for processing channeled flexible endoscopes, which carry a much higher bioload after use and have different design properties than non-channeled endoscopes.272,273 Other technologies may be effective for processing non-channeled endoscopes.
In a quasi-experimental study to compare various methods for processing non-channeled flexible laryngoscopes, Liming et al274 applied eight different processes to patient-used endoscopes, sampled the endoscopes after processing, and compared the results. The methods applied included a
○ 30-second wash with utility water,
○ 30-second scrub with antimicrobial soap,
○ 30-second wipe with 70% isopropyl alcohol,
○ 30-second scrub with antimicrobial soap followed by a 30-second wipe with 70% isopropyl alcohol,
○ 30-second wipe with a germicidal cloth,
○ 12-minute soak in orthophyalaldehyde,
○ 15-minute soak in orthophyalaldehyde, and
○ 20-minute soak in orthophyalaldehyde.
The researchers found that each of the methods used was statistically efficacious in removing bacterial contamination and equally as effective as HLD. The researchers concluded that fast, cost-effective practices were acceptable for processing non-channeled flexible endoscopes.
In a quasi-experimental study to determine the efficacy of various cleaning and disinfecting methods in reducing bacterial and fungal loads on flexible fiberoptic laryngoscopes, Chang et al272 contaminated clean endoscopes with S aureus and C albicans. The researchers exposed the contaminated endoscopes to
○ 20-, 15-, 10-, and five-minute soaks in orthophalaldehyde after precleaning in an enzymatic cleaning solution;
○ 20-, 15-, 10-, and five-minute soaks in orthophalaldehyde without precleaning in an enzymatic cleaning solution;
○ a five-minute soak in enzymatic cleaning solution;
○ a 30-second wipe with antibacterial soap and water;
○ a 30-second wipe with 70% isopropyl alcohol;
○ a 30-second wipe with antibacterial soap followed by a 30-second wipe with 70% isopropyl alcohol; and
○ a 30-second wipe with a germicidal cloth.
All exposures were followed by a 30-second rinse with utility water. The results showed that all exposures except the five-minute soak in enzymatic cleaning solution were successful in completely eliminating the S aureus and C albicans from the contaminated endoscopes. The researchers concluded that short and simple cleaning and disinfecting protocols for non-channeled endoscopes were acceptable without sacrificing efficacy and patient safety.
In a nonexperimental study to evaluate the efficacy of chlorine dioxide wipes for disinfection of flexible nasendoscopes, Tzanidakis et al273 randomly sampled the handles and distal tips of 31 endoscopes from a number of otolaryngology outpatient clinics. The samples were taken immediately before and after use on patients and immediately after cleaning. The researchers found that none of the samples were culture-positive after disinfection with the chlorine dioxide wipes. Three of the samples from the handles of the nasendoscope were positive for S aureus before use on the patient, demonstrating the potential for contamination of the area of the nasendoscope that is handled during transport that occurs after cleaning and before use. The researchers concluded that the chlorine dioxide wipes provided a safe and effective alternative to mechanical processing but recommended that personnel perform hand hygiene and don gloves before handling flexible endoscopes.
Javed et al270 conducted a survey of 200 ear, nose, and throat outpatient departments in the United Kingdom to investigate practices for disinfection of flexible nasal endoscopes. The response to the survey was 61% (n = 121). The researchers found that the preferred method for disinfection of nasal endoscopes was chlorine dioxide wipes (58%; n = 70); however, mechanical processors were also used (34%; n = 41), as were flexible sheaths (7%; n = 8). Precleaning at the point of use using an enzymatic cleaning solution was performed by the vast majority of respondents (65%; n = 79). Notably, the researchers found the use of 2% glutaraldehyde as a high-level disinfectant was rare (0.8%; n = 1).
The use of chlorine dioxide wipes may be more costly than mechanical processing270 but less costly than use of single-use endoscope sheaths.266 Phua et al275 evaluated the efficacy and cost-effectiveness of chlorine dioxide wipes compared with mechanical processing for processing flexible nasendoscopes. The researchers contaminated clean nasendoscopes with S epidermidis, exposed them to disinfection using either chlorine dioxide wipes (n = 50) or mechanical processing (n = 50), and then sampled the endoscopes. The researchers used S epidermidis as the test organism because it is representative of the normal flora found in the nasopharynx and larynx. The samples showed S epidermidis in 2% of samples (one of 50) from the chlorine dioxide group and 28% of samples (14 of 50) from the mechanical processor group. The researchers estimated costs over a 10-year period and determined that even with the expense of installation and maintenance, the mechanical processor would be less costly than the chlorine dioxide wipes and would provide an annual cost savings of approximately $25,355.82 (£16,715 [$26,467.45 in 2015 US dollars and £17,473.49 in 2015 British pounds]).
Street et al266 audited the costs of disinfection practices in a UK hospital between July 2003 and January 2004. After determining that the cost of single-use sheaths averaged $6079.94 (£4008 [$7715.66 in 2015 US dollars and £5093.79 in 2015 British pounds]) per month, the authors introduced the use of chlorine dioxide wipes and achieved a monthly cost savings of $4770.81 (£3145 [$6054.33 in 2015 US dollars and £3997 in 2015 British pounds]).
The collective evidence supports effective storage of flexible endoscopes and endoscope accessories as a means of helping to ensure devices are safe for patient use.1,12,13,16,44,45,83 The benefits of effective storage are that it helps protect the endoscopes and endoscope accessories from damage and reduces contamination.1,12,13,16,44,45,83 Some evidence is limited due to inconsistency in outcome measures, small sample sizes,276–282 and lack of a control.283–287 There is no consensus regarding maximum safe storage times.1,12,13,15,16,18–22,27,44,83
IX.a. Cabinets used for storage of flexible endoscopes should be situated in a secure location in the clean workroom of the endoscopy processing room in a two-room design or in a separate clean area close to, but not within, the endoscopy procedure room.65,288 [3: Moderate Evidence]
Situating the storage cabinet in a secure location helps protect inventories of flexible endoscopes and supplies that are vulnerable to misappropriation.69,288 Locating the storage cabinet in the clean workroom or in a clean area outside of the procedure room helps prevent contamination of processed endoscopes.69
Ensuring storage cabinets have doors and are separated from sinks by at least 3 ft (0.9 m) provides protection and reduces the potential for processed flexible endoscopes to be contaminated by water droplets.12,13,16,22,23,27
IX.b. Flexible endoscopes should be stored in accordance with the endoscope and storage cabinet manufacturers’ IFU. [5: Benefits Balanced with Harms]
Following the manufacturers’ IFU helps ensure safe and effective storage of endoscopes.
The collective evidence shows that optimal storage of flexible endoscopes facilitates drying, decreases the potential for contamination, and provides protection from environmental contaminants.69,85,288
A wide variety of storage cabinets are available.20 Drying cabinets include a drying system that circulates HEPA-filtered air through the cabinet while filtered air under pressure is forced through the endoscope channels.69,276,278 The internal and external surfaces of the endoscope are continuously dried, suppressing bacterial growth.12,20,69,276,277 Studies related to the efficacy of drying cabinets compared with other methods of storage showed that drying cabinets effectively limited bacterial proliferation during storage.276–278,283
In a quasi-experimental study to determine whether bacterial growth occurred in flexible endoscopes during a 72-hour storage period in a drying cabinet, Foxcroft et al276 processed 55 endoscopes, sampled the endoscopes, stored 40 of the endoscopes in a drying cabinet designed for horizontal storage of the endoscopes, and placed 15 of the endoscopes in an open storage cabinet in the endoscopy unit designed for vertical storage of the endoscopes. Each endoscope in the drying cabinet was connected individually to the HEPA-filtered air source. The cabinet was opened eight times daily to simulate normal use. At the end of the 72-hour storage period, the endoscopes were removed and sampled.
The researchers found that of a total of 64 samples collected from the endoscopes stored in the drying cabinet, only one sample (taken immediately after processing) showed bacterial growth (1 CFU coagulase-negative Staphylococcus). The researchers theorized this was likely the result of laboratory contamination since no other cultures from the endoscope were positive. Of the 44 samples collected from the endoscopes stored in the open cabinet, only one sample (taken immediately after processing) showed bacterial growth (1 CFU Streptococcus, 1 CFU Propionbacterium). The researchers also placed culture plates in the storage cabinets to evaluate and compare environmental contaminants within the cabinets. They found that the culture plates from the drying cabinet had significantly fewer organisms detected than the culture plates placed in the open cabinet. The researchers concluded that a 72-hour storage time did not result in increased bacterial counts in any of the stored endoscopes.276
Grandval et al283 evaluated the microbial levels of endoscopes after clinical use and processing, followed by 72 hours of storage in
a drying cabinet designed for horizontal storage of the endoscopes (Group 1; n = 41 [colonoscopes = 13; gastroscopes = 21; duodenoscopes = 7]),
a dedicated storage cabinet designed for vertical storage of the endoscopes without daily disinfection (Group 2; n = 41 [colonoscopes = 17; gastroscopes = 17; duodenoscopes = 7]), and
a dedicated storage cabinet designed for vertical storage of the endoscopes with daily disinfection (Group 3; n = 41 [colonoscopes = 20; gastroscopes = 15; duodenoscopes = 6]).
The researchers found that 100% of the Group 1 endoscopes had a contamination level consistent with the preset target level (< 5 CFU/endoscope), and 56% of these (n = 23) were completely free of contamination. Of the Group 2 and 3 endoscopes, 88% (n = 36) had a contamination level consistent with the preset target level. Of the Group 2 endoscopes, 41% (n = 17) were completely free of contamination, and of the Group 3 endoscopes, 61% (n = 25) were completely free of contamination. The researchers concluded that the use of a drying cabinet was the most effective method for maintaining microbial loads within the preset target level.283
In a quasi-experimental study of the efficacy of a drying cabinet, Pineau et al277 artificially contaminated one colonoscope, one gastroscope, and one enteroscope with P aeruginosa; stored them first inside and then outside of a drying cabinet designed for vertical storage of the endoscopes; and then sampled the endoscopes at 12, 24, 28, and 72 hours. The results showed that when the endoscopes were stored in the drying cabinet, microbial contamination levels were lower than the number of bacteria initially introduced. The researchers theorized that the level would continue to decrease considerably thereafter. For endoscopes stored outside of the drying cabinet, microbial levels were stable or increased. These data demonstrated the advantages of drying cabinets in limiting bacterial proliferation in the internal channels of endoscopes during storage.
Wardle278 conducted a quasi-experimental study to determine whether gastroscopes and colonoscopes stored in a drying cabinet designed for vertical storage of the endoscopes grew microorganisms in the channels within 72 hours. The researcher evaluated the microbial levels of two gastroscopes and six colonoscopes after clinical use and processing followed by 72 hours of storage in a drying cabinet. The results showed there was no microbial growth in any of the endoscopes. The researcher concluded that flexible endoscopes could be stored in the drying cabinet and used without reprocessing for up to 72 hours but speculated that because of the effectiveness of the cabinet, the endoscopes could be safely used after storage for up to one week.
IX.b.2. If a drying cabinet is not available, flexible endoscopes may be stored in a closed cabinet with HEPA-filtered air that provides positive pressure and allows air circulation around the flexible endoscopes.1,13,19,27,65,85 [3: Moderate Evidence]
Ventilation promotes continued drying of the endoscope. Using HEPA-filtered air may help prevent bacterial growth in the endoscope. Positive pressure may help prevent contamination of stored endoscopes.
IX.c. Flexible endoscopes that have been mechanically processed should be stored in a cabinet that is either
○ designed and intended by the cabinet manufacturer for horizontal storage of flexible endoscopes or
[1: Strong Evidence]
Some drying cabinets are designed by the manufacturer for horizontal storage of flexible endoscopes. Using a cabinet of sufficient height, depth, and width helps prevent damage that might occur from one endoscope hitting another.16 Hanging flexible endoscopes vertically helps prevent coiling or kinking of the endoscope.12,17,65
Leaving valves open and removable parts detached facilitates drying of the endoscope.85 Insufficient drying creates an environment conducive to microbial growth and promotes the formation of biofilm.82 Storing removable parts with the endoscope helps prevent loss and facilitates traceability.13,22
Alfa et al131 surveyed 37 hospitals across Canada and collected samples from the biopsy channel of duodenoscopes to assess processing practices and evaluate levels of bioburden in patient-ready duodenoscopes. The researchers found that 43% of centers (n = 16) were compliant with national processing guidelines. All of the samples with low levels of organisms (< 200 CFU/mL) had gram-positive organisms, whereas the samples with more than 200 CFU/mL had predominantly gram-negative organisms. S maltophilia was the most common organism (ie, in six of eight samples). The researchers suggested that this was likely caused by growth of water-related organisms resulting from removable parts being left on the endoscope during storage.
After identifying two incidents in which used, contaminated flexible endoscopes were returned to the clean storage area without HLD, Nomides et al289 created a visual cue that would readily identify endoscopes that had been processed and were ready for patient use. Infection prevention and sterile processing team members worked with a manufacturer to develop a green locking tie that was applied to the endoscopes after processing. The tie prevented the endoscope from being used until removal by the user.289
Personnel who processed flexible endoscopes were educated about the new system and the use of locking ties was implemented in all areas where endoscopes were processed. Endoscopes with the locking tie were readily identified as processed and ready for patient use. If there was no tie on the endoscope, it was processed and a tie was applied before storage. After implementation of this system, 94% of the endoscopy suites were compliant, and no additional incidents of using contaminated endoscopes were identified. The authors concluded that the use of a distinct, visual cue was an effective way to identify processed endoscopes and improve patient safety.
IX.f. Flexible endoscopes and storage cabinets should be visually inspected for cleanliness before endoscopes are placed into or removed from storage.13
○ If there is any evidence of contamination of the endoscope (eg, soil, moisture), the endoscope should be reprocessed before use.13
○ If there is any evidence of contamination of the cabinet (eg, wet spots, soil, fecal odor), all endoscopes in the cabinet should be removed and reprocessed and the cabinet should be cleaned.
[2: High Evidence]
Reprocessing endoscopes that could be contaminated helps ensure they are safe for use. Visible soil in the storage cabinet may indicate that one or more of the stored endoscopes is contaminated. Soil in the cabinet may contaminate endoscopes stored in the cabinet.13
IX.g. Personnel should wear clean, low-protein, powder-free, natural rubber latex gloves or latex-free gloves when handling processed flexible endoscopes and when transporting them to and from the storage cabinet. [2: High Evidence]
Sterile gloves are not required for handling processed flexible endoscopes unless the endoscope is intended to be placed on a sterile field.
Wearing clean gloves may lessen contamination of processed flexible endoscopes by the hands of personnel.69 Using low-protein, powder-free natural rubber latex gloves or latex-free gloves can minimize latex exposure and the risk of reactions in both health care workers and patients.42 Studies related to storage of flexible endoscopes have confirmed endoscope contamination from the hands of personnel and environmental surfaces.279–282,284,286,287
Muscarella290 described the case of a processed endoscope randomly selected from an endoscope storage cabinet for surveillance purposes that yielded positive growth for both patient-borne and environmental bacteria. To investigate the potential for disease transmission, a second colonoscope was sampled immediately after use (ie, the positive control), and a third colonoscope that had been sterilized with ethylene oxide was also sampled (ie, the negative control). Environmental surfaces were sampled, as were the hands and fingernails of personnel who handled the endoscopes. The investigator found that the bacteria from the insertion tube of the negative control and contaminated colonoscope yielded S aureus identical to the strain cultured from the fingernails of a newly hired team member. These results suggested that the team member’s hands and fingernails were the source of the bacteria and contamination of the colonoscope after processing. The investigator recommended that personnel wear clean gloves when handling processed endoscopes to prevent contamination of endoscopes before they are used on patients.
IX.h. A multidisciplinary team that includes infection preventionists, endoscopy and perioperative RNs, endoscopy processing personnel, endoscopists, and other involved personnel should establish a policy to determine the maximum storage time that processed flexible endoscopes are considered safe to use without reprocessing. [3: Moderate Evidence]
The collective evidence regarding the maximum safe storage time for processed endoscopes is inconclusive. Recommendations from professional organizations for maximum storage times for flexible endoscopes are not in agreement; recommended storage times range from three hours to one month (Table 4).
There is limited evidence to definitively establish the length of time that processed flexible endoscopes remain safe for use during storage. Studies have shown that when correctly processed, flexible endoscopes may be safe to use for 48 hours to 56 days after processing.279,280,282,284–287 There are benefits to reducing unnecessary processing that include reduced processing costs (eg, personnel, processing supplies), reduced wear and tear on the endoscope and processing equipment, and lower replacement and repair costs.280,286 Safe storage times may be affected by factors unique to the facility including the type of endoscopes processed and stored, processing effectiveness (eg, level of residual contamination), storage conditions (eg, restricted access, drying cabinet, HEPA-filtered air), compliance with manufacturers’ IFU (ie, endoscope, mechanical processor, storage cabinet), frequency of use, and patient population.22
In a nonexperimental study to evaluate the survival of aerobic bacteria and fungi in gastrointestinal endoscopes that were processed after routine procedures and stored in an endoscope cabinet over the weekends, Alfa et al285 tested all channels from 20 flexible gastrointestinal endoscopes (ie, five gastroscopes, nine colonoscopes, six duodenoscopes) used at an endoscopy clinic. The endoscopes were sampled for the presence of bacteria and fungi every Monday morning during a seven-month period. Bacteria and fungi were detected in 50.1% (n = 192) of the 383 channels tested. Of the 141 endoscopes tested, 14.1% (n = 20) had detectable microbial growth in at least one channel. The researchers concluded that with correct processing and drying, flexible endoscopes were safe to use for 48 to 72 hours after processing.
Osborne et al284 conducted a prospective, observational study to determine a safe shelf life for flexible endoscopes in a four-suite gastroenterology unit. All flexible endoscopes in active clinical use (ie, 23 endoscopes) during a three-week period were sampled before storage and when removed from storage (N = 194). The median shelf life ranged from 5.27 hours to 165.35 hours. The researchers found that 15.5% of samples were culture-positive (n = 30); however, only 0.5% were positive for pathogenic microorganisms (n = 1). The researchers concluded that when processed and stored correctly, the endoscopes were safe to use for at least 120 hours.
Rejchrt et al279 evaluated the bacterial load of gastroscopes, duodenoscopes, and colonoscopes stored in a dust-proof cabinet for five days. After clinical use, the endoscopes were cleaned at the point of use, manually cleaned, mechanically processed without an alcohol flush, sampled, and then stored hanging vertically in the cabinet. The researchers sampled the endoscopes for aerobic and anaerobic bacteria, including bacterial spores, and for Candida species after five days of storage. The results showed that all endoscopes were culture-negative after processing. A total of 135 samples were obtained after storage, four of which were positive for normal skin flora (Corynebacterium pseudo-diphteriae, S epidermidis). Notably, these samples were taken from the external surface of the endoscopes. All of the samples from the internal channels of the endoscopes were negative.
In a second phase of the study, 10 endoscopes were mechanically processed and stored in a dust-proof cabinet for five days and then sampled. All 10 samples were culture-negative. The researchers concluded that when correctly processed and stored, flexible endoscopes were safe to use for up to five days without reprocessing.279
Riley et al287 conducted a nonexperimental, simulated study to establish an acceptable duration of storage before reprocessing for flexible colonoscopes processed with a liquid chemical sterilant. The researchers artificially contaminated all channels of a colonoscope with S aureus, P aeruginosa, and B subtilis. The endoscope was manually cleaned, sampled, processed, and stored by hanging vertically in a ventilated endoscope storage cabinet. The endoscope was sampled five times after 24 hours of storage and five times after 168 hours of storage. The results showed no growth at 24 hours. At 168 hours, there was no bacterial growth on four of five occasions (80%) and sparse growth (< 5 CFU/mL) of two non-test organisms (ie, coagulase-negative Staphylococcus [skin flora], Micrococcus species [skin and environmental flora]). The researchers theorized that the presence of the organisms was not a result of inadequate processing but of contamination during testing procedures or storage. The researchers concluded that when correctly processed and stored, flexible endoscopes were safe to use for a period of seven days before reprocessing.
In a multiphase study to assess the microbiological load of endoscopes after HLD, Vergis et al280 evaluated four duodenoscopes and three colonoscopes. In Phase 1, the endoscopes were sampled daily after HLD for a period of two weeks. This process was repeated in Phase 2. In Phase 3, the endoscopes were sampled daily after HLD for a period of seven days. The researchers found that in Phase 1, six of 70 samples (8.6%) were culture-positive. No cultures were positive in Phase 2. In Phase 3, one endoscope had a positive culture for S epidermidis, a low-virulence skin organism. The researchers concluded that with correct processing and storage, flexible endoscopes were safe to use for a period of at least seven days and possibly up to 14 days before reprocessing.
Brock et al286 conducted a prospective, observational study to demonstrate whether flexible endoscopes were safe to use after storage for as long as 21 days before reprocessing. The researchers tested four duodenoscopes, two gastroscopes, and four colonoscopes. Immediately after use, the endoscopes were precleaned at the point of use, leak tested, manually cleaned, mechanically processed, flushed with alcohol, dried, sampled, and stored in a dust-free endoscope storage cabinet until removed for sampling at seven, 14, and 21 days. Notably, the cabinet was also used for storing endoscopes in active clinical use and was left open during the day but closed at night for security.
The results showed there were 33 positive cultures from 28 of the 96 sites tested, resulting in a 29.2% overall contamination rate. Of the culture-positive samples, 29 were typical skin or environmental contaminants, and thus clinically insignificant. Four potential pathogens were sampled that included Enterococcus, C parapsilosis, alpha-hemolytic Streptococcus, and Aureobasidium pullulans; however, the researchers theorized they were likely clinically insignificant as each was only recovered at one time point at one site and all grew in low concentrations. There were no true pathogenic isolates. The researchers concluded that correctly processed and stored flexible endoscopes were safe to use for a period of 21 days before reprocessing.286
Saliou and Baron291 responded that the level of bacterial colonization in the study might have been underestimated by the researchers’ use of sterile water for culture sampling. Brock et al291 responded that the sampling methods they used were acceptable and were recommended by professional organizations such as ESGE, the CDC, and the Gastroenterological Society of Australia.
In a quasi-experimental study to examine bacterial growth in colonoscopes after various storage times, Ingram et al282 sampled four new colonoscopes for anaerobic and aerobic bacteria after processing and after storage for three, five, seven, 14, 21, 28, 42, and 56 days. The colonoscopes were stored vertically in an open-air storage area. The results showed that none of the endoscopes were culture-positive after three, five, or seven days of storage. After 14 days of storage, one of the endoscopes had fewer than 2 CFU of S epidermidis and Staphylococcus hominis, both common skin flora. The only other microbial growth was ≤ 1 CFU of S epidermidis noted in one of the endoscopes after 42 days of storage. None of the endoscopes had bacterial growth at 56 days. The researchers concluded that when correctly processed and stored, the period of time for which flexible endoscopes were considered safe to use before reprocessing could be extended to 56 days; however, further research examining viral and fungal growth on stored endoscopes was warranted.
Schmelzer et al292 conducted a systematic review to evaluate the evidence related to endoscope storage time and included 10 studies that measured the length of endoscope storage time and microbial growth. They concluded that flexible endoscopes were safe to use for a period of seven days before reprocessing; however, the acceptable length of storage was dependent on effective processing, thorough drying, controlled storage, and microbiological surveillance.
IX.h.1. The multidisciplinary team should establish a policy for removing and reprocessing the endoscope before use if the maximum storage time has been exceeded. [5: Benefits Balanced with Harms]
IX.i. Storage cabinets used for flexible endoscopes should be cleaned and disinfected with an EPA-registered hospital-grade disinfectant when visibly soiled and on a regular (eg, daily, weekly) basis.13,15,16,65 [2: High Evidence]
Visible soil in the storage cabinet may contaminate endoscopes stored in the cabinet.13 Areas and equipment that are not cleaned according to a schedule may be missed during routine cleaning procedures and become environmental reservoirs for dust, debris, and microorganisms.
IX.i.1. A multidisciplinary team that includes infection preventionists, endoscopy and perioperative RNs, endoscopy processing personnel, endoscopists, and other involved personnel should should establish a policy to determine the cleaning frequency of the storage cabinet. [5: Benefits Balanced with Harms]
Facilities with high volumes of endoscopy procedures will require more frequent cleaning of the storage cabinet.
IX.j. Sterilized items (eg, biopsy forceps) should be stored in a sterile storage area and in accordance with the AORN Guideline for Sterilization.256 [4: Limited Evidence]
The health care organization should maintain records of flexible endoscope processing and procedures.
Records provide data for the identification of trends and demonstration of compliance with regulatory requirements and accreditation agency standards.
Highly reliable data collection is necessary to demonstrate the health care organization’s progress toward quality care outcomes.293 Effective management and collection of health care information that accurately reflects the patient’s care, treatment, and services is a regulatory requirement294–297 and an accreditation agency standard for both hospitals298,299 and ambulatory settings.299–306
X.a. Records related to flexible endoscope processing should include the
○ disposition of defective items or equipment,3 and
[2: High Evidence]
Records of flexible endoscope processing enable traceability in the event of a processing failure.13,20,69,77,84 Records of endoscopes, mechanical processors or sterilizers, and processing solutions provide a source of evidence for review during investigation of clinical issues, including infections and pseudo-infections.44 Records of water systems, endoscopes and accessories, and processing equipment maintenance provide evidence of maintenance,69 compliance with manufacturers’ IFU, and information that may be useful in determining the need for repair or replacement. Records of repairs may help to identify trends in endoscopes and processing equipment damage and help to define practices that may reduce damage.
X.b. Records related to flexible endoscope procedures should include the
[2: High Evidence]
X.c. Records should be maintained for a time period specified by the health care organization.77 [4: Limited Evidence]
Personnel with responsibility for processing flexible endoscopes should receive initial and ongoing education and complete competency verification activities related to processing flexible endoscopes.
Initial and ongoing education of endoscopy personnel facilitates the development of knowledge, skills, and attitudes that affect safe patient care. It is the responsibility of the health care organization to provide initial and ongoing education and to verify the competency of its personnel307; however, the primary responsibility for maintaining ongoing competency remains with the individual.308
Competency verification activities provide a mechanism for competency documentation and help verify that personnel processing flexible endoscopes and accessories understand the principles and processes necessary for effective processing and reducing the risk of infection from flexible endoscopes and mechanical processors.
Ongoing development of knowledge and skills and documentation of personnel participation is a regulatory requirement294–297 and an accreditation agency standard for both hospitals309,310 and ambulatory settings.310–316
XI.a. The health care organization should establish education and competency verification activities for its personnel and determine intervals for education and competency verification related to processing flexible endoscopes and accessories. [4: Limited Evidence]
Education and competency verification needs and intervals are unique to the facility and to its personnel and processes.
To determine whether deficiencies existed in the processing of contaminated flexible sigmoidoscopes in family practice and internal medicine offices and whether education of office personnel resulted in a correction of identified deficiencies, Jackson and Ball317 conducted a prospective review of processing before and after an educational course. A total of 25 persons from 19 offices (ie, 14 family practice, five internal medicine) attended one of three separate educational sessions. The course included both didactic and hands-on instruction. The instructor was a certified gastroenterology RN with infection prevention experience.
The researchers reviewed standards published by the SGNA, the Association for Professionals in Infection Control and Epidemiology (APIC), the ASGE, and the CDC, and selected 17 common standards as those most critical to effective endoscope processing. All of the participants completed a questionnaire based on the 17 standards before the course and again two months after the course. The researchers found that before the educational course, the 19 offices had between four and 11 deficiencies per office, with an average of 6.8 deficiencies per office. After the educational course, deficiencies ranged from zero to eight, with an average of 0.9 deficiencies per office. The researchers concluded that before the educational course, personnel from the family practice and internal medicine offices were insufficiently educated to perform flexible endoscope processing and that endoscopes were not being processed in accordance with standards. However, after the educational course, personnel processed the endoscopes according to the standards.
Lunn et al318 reported their experience with endoscope repairs before and after implementing an educational program designed to improve handling of flexible endoscopes and equipment. The authors retrospectively reviewed the cost of endoscope repair in the three years preceding and in the five years following an educational program that included both didactic and hands-on components. The authors found that the cost of repairs during the three years before the educational program averaged $42 per procedure ($62.18 in 2015 US dollars). After the educational program, the repair costs dropped dramatically to $8 per procedure ($10.63 in 2015 US dollars). These reduced costs were realized despite an average 10% increase in the number of procedures being performed each year. The authors concluded that an educational program was effective in decreasing the costs of endoscope and equipment repairs.
XI.b. Education and competency verification activities related to processing flexible endoscopes and accessories should include
○ maintaining records of processing and procedures for traceability12; and
[2: High Evidence]
Providing education and verifying competency helps reduce the risk of processing errors.66
XI.c. Personnel should receive education and complete competency verification activities before new flexible endoscopes, accessories, cleaning and processing solutions, equipment, or procedures are introduced. [5: Benefits Balanced with Harms]
Receiving education and completing competency verification activities before new endoscopes, accessories, cleaning and processing solutions, equipment, or procedures are introduced helps ensure safe practices in the endoscopy suite.
Policies and procedures for processing flexible endoscopes should be developed, reviewed periodically, revised as necessary, and readily available in the practice setting in which they are used.
Policies and procedures assist in the development of patient safety, quality assessment, and performance improvement activities. Policies and procedures also serve as operational guidelines used to minimize patients’ risk for injury or complications, standardize practice, direct personnel, and establish continuous performance improvement programs. Policies and procedures establish authority, responsibility, and accountability within the practice setting.
Having policies and procedures that guide and support patient care, treatment, and services is a regulatory requirement294–297 and an accreditation agency standard for both hospitals319,320 and ambulatory settings.312,320–326
XII.a. Policies and procedures related to processing flexible endoscopes should address
○ controlling and maintaining an environment that supports processing actions30;
○ precleaning at the point of use12;
○ leak testing12;
○ manual cleaning12;
○ HLD, liquid chemical sterilization, packaging, and sterilization12;
○ maintaining records of processing and procedures for traceability12; and
[3: Moderate Evidence]
Effective processing of flexible endoscopes and accessories begins with clear and detailed policies and procedures.
XII.b. The manufacturers’ IFU should be readily available to and followed by the personnel responsible for processing flexible endoscopes. The manufacturer’s IFU should be reviewed periodically, and processing practices should comply with the most current IFU. [4: Limited Evidence]
Instructions for use identify the validated processes necessary to achieve effective processing.77 Manufacturers may make modifications to their IFU when new technology becomes available, when regulatory requirements change, or when modifications are made to a device.
XII.c. Policies and procedures for managing loaned endoscopes, accessories, and equipment should be developed in accordance with the AORN Guideline for Cleaning and Care of Surgical Instruments.58 [4: Limited Evidence]
The systematic management of loaned instrumentation reduces loss and helps ensure effective processing through increased collaboration, communication, and accountability.58
The health care organization’s quality management program should evaluate processing of flexible endoscopes.
Quality assurance and performance improvement programs can facilitate the identification of problem areas and assist personnel in evaluating and improving the quality of patient care and formulating plans for corrective action. These programs provide data that may be used to determine whether an individual organization is within benchmark goals, and if not, to identify areas that may require corrective action. A quality management program provides a mechanism to evaluate effectiveness of processes, compliance with manufacturer’s IFU, endoscopy processing policies and procedures, and function of equipment.
Collecting data to monitor and improve patient care, treatment, and services is a regulatory requirement294–297 and an accreditation agency standard for both hospitals327–334 and ambulatory settings.332–345
XIII.a. The quality assurance and performance improvement program for processing flexible endoscopes should include
○ periodically reviewing and evaluating processing activities to verify compliance or to identify the need for improvement,
○ identifying corrective actions directed toward improvement priorities, and
○ taking additional actions when improvement is not achieved or sustained.
[3: Moderate Evidence]
Reviewing and evaluating quality assurance and performance improvement activities may identify failure points that contribute to errors in processing flexible endoscopes and help define actions for improvement and increased competency.85 Taking corrective actions may improve patient safety by enhancing understanding of the principles of and compliance with best practices for processing flexible endoscopes.
Evans346 described a quality improvement initiative undertaken to improve processing of flexible cystoscopes following anecdotal reports of an increased incidence of urinary tract infections after cystoscopy procedures. The author first conducted a literature search to determine best practices for processing flexible cystoscopes. She reviewed the manufacturer’s IFU to ensure cystoscopes were being processed in a manner consistent with the IFU, conducted a gap analysis to identify problematic areas, and developed a plan to address them. She then shadowed clinical personnel for two days and conducted interviews to ensure that personnel understood and adhered to best practices for effective processing. The author developed a process improvement tool to audit compliance, and provided remediation on an ongoing basis as needed. The quality improvement process was successful in improving processing of flexible cystoscopes and enhancing patient safety.
XIII.b. Personnel participating in endoscopy procedures or responsible for processing flexible endoscopes and accessories should participate in ongoing quality assurance and performance improvement activities related to processing flexible endoscopes by identifying processes that are important for
○ monitoring quality,
○ developing strategies for compliance,
○ establishing benchmarks to evaluate quality indicators,
○ collecting data related to the levels of performance and quality indicators,
○ evaluating practice based on the cumulative data collected,
○ taking action to improve compliance, and
○ assessing the effectiveness of the actions taken.
[2: High Evidence]
Participating in ongoing quality assurance and performance improvement activities is a primary responsibility of endoscopy personnel engaged in practice.307
XIII.c. The health care organization should monitor compliance with the use of PPE in the endoscopy suite. [3: Moderate Evidence]
In a survey commissioned by the Disinfection Management Committee of the Korean Society of Gastrointestinal Endoscopy, Park et al190 assessed compliance of 100 nurses and nursing assistants from the endoscopy units of eight secondary or tertiary Korean hospitals with Korean national guidelines for processing flexible endoscopes. The researchers found that the activity with the lowest compliance was wearing protective eyewear, with only 32% of respondents complying; 72% complied with wearing surgical masks, and 80% complied with wearing gloves. The researchers concluded that education combined with periodic surveillance could improve compliance.
Angtuaco et al347 conducted a survey of 250 gastroenterologists and gastrointestinal endoscopy nurses from the American Board of Internal Medicine and the SGNA to determine and compare compliance with standard precautions and the use of PPE. A total of 77 gastroenterologists and 157 gastrointestinal endoscopy nurses responded to the survey. The results of the survey showed that
○ 32% of the gastroenterologists (n = 25) and 50% of the nurses (n = 79) washed their hands before and after contact with patients.
○ 5% of the gastroenterologists (n = 4) and 30% of the nurses (n = 47) wore gloves during patient contact.
○ 14% of the gastroenterologists (n = 11) and 21% of the nurses (n = 33) wore face shields during procedures.
○ 29% of the gastroenterologists (n = 22) and 46% of the nurses (n = 72) wore protective gowns during procedures.
When asked to provide an assessment of their own compliance with standard precautions and use of PPE, 45% of gastroenterologists (n = 35) and 60% of nurses (n = 94) reported that they always complied. The researchers concluded that compliance with standard precautions for both groups was low, but was greater for the nurses than for the gastroenterologists.347
In a survey of 300 randomly selected gastrointestinal endoscopy units in Spain to assess compliance with occupational risk prevention measures, Baudet et al348 received responses from 196 units (65%). The researchers found that personnel in
○ 19% of the units (n = 38) wore protective eyewear,
○ 99% of the units (n = 195) wore gloves,
○ 46% of the units (n = 90) wore masks, and
○ 21% of the units (n = 42) wore protective gowns.
The researchers concluded that compliance with occupational risk prevention measures in Spain was lacking and improvement was needed.
XIII.d. A multidisciplinary team that includes facility engineers, endoscopy processing personnel, infection preventionists, and other involved personnel should establish a policy to determine processes for monitoring and auditing facility water quality to ensure compliance with requirements for endoscope processing as specified in the endoscope, processing equipment, and processing products manufacturers’ IFU. Water quality and water filtration systems should be assessed at established intervals119,213,214,216,247,349–358 and after major maintenance to the water supply system.359 [1: Strong Evidence]
Water quality varies seasonably and after water-source maintenance. Periodic testing can indicate whether the chemical combination used to condition the water used for endoscope processing requires adjusting.119 Water-quality checks measure objective performance criteria (eg, pH, hardness) that have a direct effect on the outcomes.119 The quality of the water is a consideration when determining the necessary level of filtration.119,215,353,354,357,359–362 The need for repairs or modifications to the water treatment system can be identified from a water-quality check.119 Monitoring water quality also assists in determining the performance of the filters and whether replacement is necessary.353,356,358 Failing to regularly replace filters may result in bacterial growth on the filter and contamination of the water supply.354,356 Contamination of the water supply may increase the patient’s risk for infection. Monitoring water quality provides an opportunity for controlling exposure of the endoscope to waterborne contamination and subsequent exposure of patients to potential pathogens.214,358,361,363
Quality processes can be enhanced by audits that are conducted on a regular basis.119,358,362 Regular monitoring and auditing of water quality may help prevent incidents related to contaminated water,247,349,350,352,353,362,364 including infection365 and pseudo-infection.213–216,356,357,359,360
Rossetti et al357 reported 16 isolates of Mycobacterium gordonae from 267 patients undergoing bronchoscopy procedures. This finding was significant because in the previous seven years only one isolate of M gordonae was found among 1,368 patients. The investigators found there had been a failure in water filter replacement and water system maintenance. Replacement of the water filters and restoration of periodic assessment of water quality ended the pseudo-infections.
Rosengarten et al215 reported a cluster of Burkholderia cepacia pseudo-infections associated with a contaminated mechanical processor in a bronchoscopy unit. Bronchoalveolar lavage samples obtained from three patients on three consecutive days grew organisms identified as B cepacia on culture; however, there were no clinical manifestations of infection in any of the patients. All of the patients had been examined with the same bronchoscope. Examination of the mechanical processor revealed that the 0.2-micrometer bacteria-retentive filter on the water supply line was missing, and this missing filter was the probable cause of the cluster of pseudo-infections. The mechanical processor was thoroughly cleaned and disinfected, and the missing filter was replaced. Subsequent samples were negative for B cepacia. The investigators concluded that a failure to follow the manufacturer’s IFU by not installing the 0.2-micrometer filter had enabled bacteria to enter the mechanical processor and contaminate it and the bronchoscopes.
Chroneou et al213 described a pseudo-outbreak of M chelonae in bronchoalveolar lavage fluid that was traced to a contaminated mechanical processor. The investigators obtained environmental samples from 17 different components of the processor, from the brushes used to clean the bronchoscopes, and from the utility water used to rinse the bronchoscopes. The investigators found the source of the outbreak was a filtration system malfunction that occurred because of a failure to change the water filters on schedule. It was not clear who had the responsibility for changing the filters at the scheduled time. Developing a process to ensure the water filters were changed on a monthly basis and assigning this responsibility to biomedical personnel eliminated the pseudo-outbreak strain.
XIII.e. A multidisciplinary team that includes facility engineers, endoscopy processing personnel, infection preventionists, and other involved personnel should collaborate with manufacturer service personnel to determine schedules for preventive maintenance of flexible endoscopes, mechanical processors, and other equipment (eg, the drying cabinet) used for processing flexible endoscopes. [2: High Evidence]
A regular program of preventative maintenance helps identify and mitigate potential risks.22 Mechanical processors that are not maintained or functioning correctly may cause processing failures of flexible endoscopes and increase the risk for transmission of infection.209,218,367 Schlenz and French209 reported an outbreak of multidrug-resistant P aeruginosa infection involving 11 patients, eight of whom had undergone bronchoscopy procedures with two of three facility bronchoscopes that had been processed in a malfunctioning mechanical processor. There were no maintenance records, and no maintenance had been performed on the processor since its purchase one year previously. The tubing, filter, and pump system had to be replaced before the processor was free of Pseudomonas species. The bronchoscopes had likewise not been maintained and required replacement parts. The investigators concluded that regular, controlled, professional maintenance of mechanical processors and bronchoscopes was necessary for safe, effective processing of flexible endoscopes.
In a study to monitor the quality of gastrointestinal endoscope processing, Chiu et al367 randomly sampled flexible endoscopes immediately after completion of mechanical processing. During the study, the researchers found that the endoscopes processed in one particular mechanical processor were culture-positive in spite of manual cleaning and mechanical processing. The service representative discovered that a relief valve from the mechanical processor was damaged and loose. After the valve was replaced, subsequent cultures were negative. The researchers recommended that mechanical processors undergo preventive maintenance at least every three to six months.
Méan et al218 reported an incident involving 72 patients who underwent endoscopy procedures. The endoscopes used during the procedures were mechanically processed in a malfunctioning mechanical processor. The malfunction was reported by a nurse who became alarmed when the processor printed a validation ticket even though there was no cleaning solution in the mechanical processor. The processing failure was caused by a malfunction of the sensor whose function was to control the level of cleaning solution in the processor. An undetermined number of cleaning cycles had been skipped; however, the manual cleaning and HLD cycles were completed correctly. The investigators concluded that this incident highlighted the importance of regular preventive maintenance for mechanical processors.
Regular maintenance and replacement of endoscope lumens contaminated with biofilm may help to prevent transmission of infection.368 In some cases, outbreaks of infection136,217,365,369,370 and pseudo-infection368 transmitted via flexible endoscopes were only stopped when the scope was sent to the manufacturer for repair and replacement of the lumen.368
DiazGranados et al371 reported a cluster of 12 patients with respiratory cultures positive for P aeruginosa, 11 of whom had undergone bronchoscopy with the same bronchoscope. Processing procedures were reviewed by the infection prevention team and found to be acceptable. Despite appropriate processing, P aeruginosa was recovered from the bronchoscope. The investigators found that the bronchoscope had been in use for 16 months, and during that time, regular visual inspections and leak testing had been performed. The bronchoscope had been submitted to the manufacturer for repair three times but not for preventive maintenance, and the last repair was performed eight months before the pseudo-outbreak. The bronchoscope was sent to the manufacturer who found multiple defects including kinking of the forceps channel tube, damage to the bending section sheath cover, pinching of the insertion tube, and peeling of the light-guide tube coating. The investigators concluded that regular preventive maintenance inspections were necessary to prevent similar occurrences.
Corne et al368 investigated an outbreak of P aeruginosa infections (n = 9) and pseudo-infections (n = 7). Inspection of the internal channels of the involved bronchoscopes revealed large surface defects in the internal channels. The researchers theorized the defects were caused by biopsy forceps. The breaches in the internal channels prevented effective cleaning and processing of the endoscopes even though processing personnel adhered to the manufacturer’s IFU. The outbreaks were controlled when the manufacturer replaced the inner channels of the bronchoscopes and the facility began using single-use biopsy forceps. The investigators concluded that the outbreaks emphasized the need to establish maintenance procedures for detecting damage to the internal channels of flexible bronchoscopes.
Qiu et al369 investigated a duodenoscope that was manually cleaned and mechanically processed multiple times but continued to be culture-positive for P aeruginosa. The duodenoscope was sent to the manufacturer, who replaced the internal lumens of the device. Thereafter, the duodenoscope was culture-negative.
Zweigner et al217 reported an outbreak of carbapenem-resistant K pneumoniae involving eight patients. A review of the processing procedures did not identify any deviations from the manufacturer’s IFU. The outbreak ended when the bronchoscopes associated with the infections (n = 2) were submitted to the manufacturer who found defects in the internal channels of both endoscopes. The investigators concluded that the outbreak underlined the importance of regular preventive maintenance for flexible endoscopes.
In a CDC Epidemic Intelligence Service370 investigation to review a duodenoscope-associated cluster of carbapenem-resistant Bacteriaceae infections in which no breaches in processing or device defects were identified to explain transmission, the investigators returned all duodenoscopes with positive cultures (n = 8) to the manufacturer for assessment. Only one duodenoscope was returned because it was not functioning correctly. The remaining seven duodenoscopes were returned as part of the investigation and had no obvious defects or functional issues. They had undergone and passed leak tests after each use and were functioning without any noticeable problems.
The manufacturer identified critical repair issues in all eight duodenoscopes that included cracks, leak test failures, frayed bending sections, and other issues related to biopsy forceps passage (eg, breaches in the biopsy channel). Notably, there was no preventive maintenance schedule recommended by the manufacturer. The investigators concluded that the lack of preventive maintenance was concerning. A process for the manufacturer to regularly inspect and service duodenoscopes was established that included random selection of duodenoscopes that were then sent to the manufacturer at predetermined intervals.370
Damage may occur with repetitive use of endoscopes that suggests a need for limiting the duration a reusable device is used.372 Lee et al372 conducted a quasi-experimental study to compare differences in surface alterations between not-aged and simulated-aged samples of endoscope materials. The researchers inoculated the samples with E coli, P aeruginosa, and Mycobacterium terrae artificial test soil, and then exposed the endoscope materials to identical processing conditions. The researchers found significantly more abrasions, cracks, and holes in the aged samples. They concluded that surface alterations on the samples of the endoscope material increased during repetitive use and processing. The possibility of accumulation of microorganisms and organic substances increased accordingly, and this also increased the risk of infection transmission.
XIII.e.2. The frequency of preventive maintenance should be based on variables that are unique to the facility.366 [2: High Evidence]
Variables unique to the facility, such as the type of endoscopes that are used, the amount of use of the endoscopes, the type of damage that occurs to the endoscope, the thoroughness of the cleaning processes, the implements that are used to clean the endoscopes, the type of water used in the facility, and other factors may affect the need to increase or decrease the frequency of preventative maintenance.
XIII.e.3. Mechanical processors should be tested for performance on installation; at regular, established intervals (eg, daily, weekly); after major repairs; and after changes in programmed parameters (eg, temperature, cycle time).21,58 [2: High Evidence]
Testing the function of mechanical processors confirms the equipment is operating correctly. Effective processing is dependent on correctly functioning equipment.
Preventive maintenance requires special skills and knowledge that includes systematic inspection, testing, measurement, adjustment, detection, parts replacement, and correction of device or equipment malfunction either before it occurs or before it develops into major failure. Having qualified personnel perform preventive maintenance increases the probability that repair and service will be performed correctly.58
XIII.f. Manual cleaning of flexible endoscopes should be verified using cleaning verification tests when new endoscopes are purchased and at established intervals (eg, after each use, daily). [3: Moderate Evidence]
The collective evidence shows that manual cleaning is a learned skill subject to human error.373 Cleaning verification tests are used to verify the ability of the cleaning process to remove, or reduce to an acceptable level, the organic soil and microbial contamination that occurs during use of a reusable device.77,374 Cleaning verification tests include adenosine triphosphate (ATP) and chemical reagent tests for detecting clinically relevant soils (eg, protein, carbohydrate). Periodic verification of cleaning effectiveness may help reduce errors in manual cleaning and improve effectiveness.90,183,373 No single method of cleaning verification has been established as a standard for assessing the outcome of endoscope processing.45
Efficacy of cleaning has traditionally been evaluated visually; however, visual inspection alone, even with magnification, is not sufficient to determine cleanliness of complex devices such as flexible endoscopes.12,90,374,375 Visual inspection is subjective. Infectious microorganisms are not visible to the naked eye. It is also not possible to visually inspect the lumens of flexible endoscopes.12,90,374 Residual soil may remain and prevent effective subsequent HLD or sterilization.375
There is a need for rapid testing methods to detect residual soil and verify the adequacy of manual cleaning.376 Although no studies have been conducted linking clinical outcomes with using monitors for cleaning verification,377 auditing the manual cleaning of flexible endoscopes provides an objective method for verifying cleanliness and helps ensure that insufficiently cleaned flexible endoscopes are recleaned before HLD or sterilization.90,183,377,378
Alfa et al252 conducted a quasi-experimental study to determine the type and amount of soil found in various types of flexible endoscopes before and after cleaning. The researchers’ intent was that the determination of expected soil levels would help establish parameters for worst-case soil cleaning efficacy benchmarks. The researchers assessed suction channels from 10 bronchoscopes, 10 duodenoscopes, and 10 colonoscopes immediately after use for levels of bilirubin, hemoglobin, protein, sodium ion, carbohydrate, endotoxin, and viable bacteria. An additional set of endoscope suction channels (ie, 10 bronchoscopes, 10 duodenoscopes, 10 colonoscopes) were evaluated for the same components after manual cleaning but before mechanical processing for subsequent clinical use. The researchers found the worst-case soil levels in the suction channels were
○ protein: 115 µg/cm2,
○ sodium ion: 7.4 micromole/cm2,
○ hemoglobin: 85 µg/cm2,
○ bilirubin: 299 nanomole/cm2,
○ carbohydrate: 29.1 µg/cm2,
○ endotoxin: 9852 EU/cm2, and
○ bacteria: 7.1-log10 CFU/cm2.
After cleaning, the levels of protein, endotoxin, and sodium ion were reduced five- to ten-fold. Carbohydrate and bilirubin were reduced to undetectable levels. The average load of viable bacteria was reduced from between 3-log10 to 5-log10 CFU/cm2. Residual hemoglobin was only detectable in bronchoscopes. The researchers concluded the data demonstrated that cleaning reduced or eliminated many components of organic soil, but a substantial amount of viable bacteria and protein may still remain on the endoscope.252
In a study to evaluate contamination of patient-used endoscopes using visual inspection and rapid cleaning verification tests and to determine which testing instruments and methods could be used for quality improvement initiatives related to flexible endoscope processing, Visrodia et al375 sampled endoscopes used for gastrointestinal procedures after precleaning at the point of use and after manual cleaning. During 37 examinations of 12 endoscopes, the researchers visually inspected 121 endoscope components and conducted 249 rapid cleaning verification tests. The researchers found that regardless of whether there was visible soil on the endoscope after precleaning at the point of use, all endoscopes had high levels of ATP and detectable blood or protein. Although there was no visible soil on any of the endoscopes after manual cleaning, 82% had at least one positive cleaning verification test. The researchers concluded that relying solely on visual inspection after manual cleaning and before HLD was insufficient to ensure processing effectiveness. The researchers theorized that using more than one cleaning verification testing method may be necessary to ensure contamination is consistently detected before endoscopes are processed and used on patients.
In a quasi-experimental study to determine whether colonoscope and gastroscope contamination that occurred during clinical use persisted despite processing in accordance with US guidelines, Ofstead et al379 performed microbiological cultures and rapid cleaning verification tests for ATP, protein, hemoglobin, and carbohydrate residue during 60 examinations of 15 endoscopes (ie, two new and 13 patient-used [ie, seven colonoscopes, six esophagogastroduodenoscopes without elevator channels]). Benchmarks were set at ATP < 200 relative light units (RLU), protein 120 µg/ml, carbohydrate 210 µg/ml, and hemoglobin 0.25 µg/ml. The researchers assessed endoscope contamination immediately after point-of-use precleaning, manual cleaning, HLD, and overnight storage. The researchers found that
○ after point-of-use precleaning, 13 of 13 endoscopes (100%) had detectable protein, hemoglobin, and ATP, and 12 of 13 (92%) harbored viable microorganisms.
○ after manual cleaning, 12 of 13 endoscopes (92%) had protein or ATP exceeding the benchmarks and six endoscopes (46%) had at least one positive culture.
○ after HLD, eight of 11 endoscopes (73%) were positive for contamination exceeding benchmarks, and viable microorganisms were found on seven endoscopes (64%).
○ after overnight storage, nine of 11 endoscopes (82%) were positive, and one of 11 (9%) harbored microorganisms.
Viable microorganisms were recovered from patient-ready endoscopes after all processing steps including HLD. The researchers concluded that despite processing in accordance with US guidelines, viable microorganisms persisted on patient-used flexible endoscopes, and this suggested that current guidelines might not be sufficient to ensure successful processing. The results of the study also suggested that rapid cleaning verification tests were valid and reliable and that it might be beneficial to test for both protein and ATP because one was often present without the other. Assessing the efficacy of manual cleaning using rapid cleaning verification tests allowed processing personnel to be immediately informed when test results exceeded established benchmarks. Endoscopes could then be recleaned before HLD or sterilization.379
Hansen et al380 compared ATP testing with microbiological culturing by examining 108 flexible endoscopes (ie, 40 gastroscopes, eight duodenoscopes, 42 bronchoscopes, 18 colonoscopes) after processing. Benchmarks for positive ATP were set at < 30 RLU and < 100 RLU based on the manufacturer’s IFU. The researchers considered all microbiological growth to be positive, regardless of the species or number of CFU. The researchers found that 26% of the endoscopes had bacterial growth (n = 28 [ie, nine gastroscopes, one duodenoscope, 13 bronchoscopes, five colonoscopes]). Using < 30 RLU as the benchmark, 62% of the endoscopes were positive for ATP (n = 67 [ie, 25 gastroscopes, six duodenoscopes, 24 bronchoscopes, 12 colonoscopes]). Using < 100 RLU as the benchmark, 19% were positive for ATP (n = 21; [ie, seven gastroscopes, one duodenoscope, eight bronchoscopes, five colonoscopes]). The researchers concluded that it was beneficial to implement ATP testing as a method to identify ineffective cleaning of flexible endoscopes and the need for recleaning before HLD or sterilization.
XIII.f.1. A multidisciplinary team that includes infection preventionists, endoscopists, endoscopy processing personnel, and other involved individuals should establish the type of cleaning verification test to be performed. [2: High Evidence]
There are a number of tests that can be used to assess cleaning efficacy.90,373,378,381 Chemical tests involve the use of a reagent and observing for a color change that indicates the presence of organic markers such as protein or blood.90,373,381
In a dual phase (ie, simulated-use, in-use) study to validate the use of an audit tool composed of reagent test strips in 43 endoscopy clinics across Canada, Alfa et al381 collected samples from 30 patient-used endoscopes (ie, 10 colonoscopes, 10 duodenoscopes, 10 gastroscopes) and tested them for residual protein, carbohydrate, and hemoglobin using the audit tool test strips. The test strips had three reagent pads designed to rapidly detect organic residuals of protein, carbohydrate, and hemoglobin after manual cleaning. The researchers confirmed that the audit tool flagged endoscopes with residual protein, hemoglobin, or carbohydrate.373 In the second phase of the study, the researchers sent prototype testing kits to 44 endoscopy clinics in 23 health care facilities across Canada and conducted a survey to obtain feedback from processing personnel using a 5-point analog rating scale. The results of the survey showed that processing personnel valued the audit tool and thought it was important for confirming the adequacy of manual cleaning. Respondents also thought the test was easy to use, that it should be used on some endoscopes daily, and that it should be part of the quality assurance program for the endoscopy unit.381
Quantitative tests provide a measurement against which cleaning results can be compared.90 Adenosine triphosphate bioluminescence is an example of a quantitative test.378 The item to be tested is swabbed to collect ATP, the swab is inserted into a reaction tube, and the ATP on the swab reacts with the chemicals in the reaction tube.58 The reaction tube is then inserted into a hand-held luminometer that converts the ATP released from microorganisms or human cells into a light signal, which is measured in RLU.58
Obee et al374 conducted a nonexperimental study to compare the efficacy of endoscope processing using microbiological surveillance and ATP bioluminescence. Following visual observation of manual cleaning, the researchers sampled eight different areas on 63 gastrointestinal endoscopes (N = 504) before, during, and after processing. The benchmarks for positive results were set at ATP > 500 RLU and microbiological culture ≥ 3 CFU/sample. The researchers found that a total of 32 cultures (6.3%) and 95 ATP tests (18.8%) were positive; however, after processing, only three cultures (0.6%) and one ATP test (0.2%) were positive. The researchers concluded that ATP provided a rapid means of assessing the efficacy of manual cleaning before HLD.
In a prospective study carried out in a gastrohepatology unit to evaluate using ATP bioluminescence to verify manual cleaning of flexible endoscopes, Fernando et al382 obtained samples from the lumens of endoscopes and tested the endoscopes using ATP in 120 endoscopic procedures. The samples were obtained before the procedure, after the procedure, after manual cleaning, and after mechanical processing. The ATP benchmark was set at < 100 RLU. If the after-processing benchmark was exceeded, the endoscope was reprocessed and retested. The researchers found the average RLU reading before the procedure was 48 RLU. After the procedure, the average reading was 124,052 RLU. After manual cleaning the average reading was 1,423 RLU, and after mechanical processing, the average reading was 144 RLU. The corresponding culture results before the procedure were all negative. After the procedure, only four cultures were negative. After manual cleaning, 26 cultures were negative, and after mechanical processing, all cultures were negative. Twenty-one (18%) of the post-mechanical processing cultures were initially positive; however, after reprocessing, the cultures were negative. The researchers concluded that ATP testing had the potential to play an important role in verifying that flexible endoscopes had been effectively processed and were safe to use. They posited that because the results were available so rapidly, the test could be easily performed before every procedure.
In a nonexperimental study to evaluate ATP, microbial load, and protein as potential indicators of gastrointestinal endoscope cleanliness, Fushimi et al383 sampled exterior surfaces and interior suction/accessory channels of 12 endoscopes used in 41 patients. The researchers found that before cleaning, the ATP levels were 10,417 RLU from the exterior surfaces and 30,281 RLU from the channels. After cleaning, these values decreased to 82 RLU and 104 RLU, respectively. Before cleaning, the microbial load was 5,143 CFU/sample exterior and 95,827 CFU/sample channels. After cleaning, the microbial load was 1 CFU/sample exterior and 104 CFU/sample channels. Before cleaning, the protein level was 36 µg/sample channels; after cleaning, the level was 20 µg/sample. There was a significant change in ATP and microbial load; however, the decrease in protein levels was not significant. The researchers concluded that ATP measurement provided a reliable, rapid, and practical assessment of endoscope cleanliness for routine monitoring in the clinical setting.
In a quasi-experimental, three-phase study, Sciortino et al384 investigated and evaluated the use of a portable luminometer system for detecting contamination after cleaning and HLD of flexible endoscopes. In Phase 1, the researchers conducted a microbiological analysis of 15 endoscopes (ie, five processed, one cleaned, nine contaminated). The researchers found that the five processed endoscopes were culture-negative. The other 10 endoscopes were culture-positive. Notably, the internal channel of one of the culture-positive endoscopes was visibly contaminated with feces, yet had been cleaned but not disinfected for patient use.
In Phase 2, the researchers examined 31 endoscopes and tested them before cleaning, after cleaning, after HLD, and after storage at one- to two-week intervals. The researchers found that of the 31 endoscopes tested, eight (25.8%) were sterile (0 RLU; < 1 CFU), 12 (38.7%) were clean (< 5,000 RLU; < 50 CFU), and 11 (35.5%) were contaminated (> 5,000 RLU; > 50 CFU).384
In Phase 3, the researchers tested 63 endoscopes that had been processed and stored for reuse. The results showed that none of the endoscopes were sterile, 10 (15.9%) were clean, and 53 (84.1%) were contaminated.384
The researchers found that the storage room was moist and humid, and there was an open window 16 ft from the storage cabinet. The researchers observed there were disadvantages of ATP testing that included a lack of specificity for certain pathogenic microorganisms. In addition, the swab did not reach into crevices and could not be used deep inside internal channels without potential damage to the endoscope. Regardless, the researchers concluded that application of the ATP test was beneficial because it enabled monitoring of processing problems that could be addressed and immediately corrected.384
In response to a study by Visrodia et al375 that supported the use of rapid cleaning verification tests, Whiteley et al385 criticized ATP systems because of the lack of correlation between ATP and specific pathogens of concern and because of the measurement variability between commercially branded devices. In reply, Visrodia et al386 countered that their research375 had shown that flexible endoscopes with and without visually apparent organic soil had high levels of blood, protein, and ATP. The intent of their study was to identify methods for rapidly evaluating the effectiveness of manual cleaning in the clinical setting. The ATP testing system provided a numerical result reflecting the amount of ATP present, and these data can assist in quality monitoring of flexible endoscope processing and help ensure the adequacy of manual cleaning before mechanical processing.
There are quantitative tests that can be used for cleaning verification testing of other residual soils, including
total organic carbon.90
Quantitative testing can be used as part of a quality monitoring program to observe for trends and to monitor performance of a manual or a mechanical process.58 Readings that trend lower indicate effective cleaning, whereas readings that trend higher may indicate a need for improved manual cleaning processes.58 Further research is warranted.
XIII.f.2. The multidisciplinary team should establish the benchmarks for the cleaning verification tests to be performed. [2: High Evidence]
Standards for clinically significant levels of residual soil remaining after cleaning are lacking,90 and this lack of widely accepted residual soil benchmarks has limited the implementation of rapid cleaning verification testing.373,377,378,387
Manufacturers may establish quantitative benchmarks for cleaning verification tests to measure manual cleaning of flexible endoscopes.58 Endoscopes not meeting this reference point after manual cleaning require recleaning before HLD or sterilization.58 However, variability has been identified as a concern in the use of hand-held ATP monitors, and this variability is greatest at the boundary between acceptable and unacceptable cleanliness verification.388 Variability may also lead to poor repeatability.388 The RLU reading scale has not been quantified against a known standard and therefore cannot be calibrated, diminishing inter-brand compatibility.388 An additional concern is the risk for random error, which may be undetectable in single monitoring samples.388
Whiteley et al388 investigated the reliability of ATP bioluminometers and documented precision and variability measurements using known and quantitative standard methods. The researchers subjected four commercially branded ATP bioluminometers to known quantities of various bacteria in suspension cultures. The researchers found that the variability of commercial ATP bioluminometers was unacceptably high. They concluded that the advantages of the ATP rapid response test were undermined by the imprecision of the instrument.
However, studies have demonstrated the adequacy of an ATP benchmark of < 200 RLU for ATP252,378,387 for both manual387 and pump-assisted manual cleaning.389 In a simulated-use, quasi-experimental study to validate the use of ATP for monitoring manual cleaning of flexible endoscopes, Alfa et al387 contaminated all channels of a duodenoscope with artificial test soil containing 106 CFU of P aeruginosa and E faecalis. Residual levels of ATP, protein, hemoglogin, and bioburden were calculated from an uncleaned, partially cleaned, and fully cleaned duodenoscope. The benchmarks for clean were set at ATP < 200 RLU, protein < 6.4mg/cm2, hemoglobin < 2.2 mg/cm2, and bioburden < 4-log10 CFU/cm2. The researchers found that the benchmarks for protein, hemoglobin, and bioburden were met if ATP < 200 RLU was achieved. The researchers concluded that effectively cleaned flexible endoscopes would have < 200 RLU of ATP.
In a quasi-experimental study to determine whether the published benchmarks252,378,387 for protein (< 6.4 µg/cm2), bioburden (< 4-log10 CFU/cm2), and ATP (< 200 RLU) were relevant for pump-assisted manual cleaning, Alfa et al389 sampled the suction biopsy channel of patient-used endoscopes after precleaning at the point of use (ie, 10 colonoscopes, 10 duodenoscopes, 10 gastroscopes) and after pump-assisted manual cleaning (ie, 20 colonoscopes, 20 duodenoscopes, 20 gastroscopes) and then tested them for protein, bioburden, and ATP levels. The researchers found that after pump-assisted manual cleaning, 25% of gastroscopes (n = 5) exceeded the ATP benchmark, whereas all duodenoscopes (n = 20) and colonoscopes (n = 20) were below the benchmark level. The protein and bioburden residuals were also consistently lower than existing benchmarks after pump-assisted cleaning. The researchers concluded that the benchmark for protein could be lowered to < 2 µg/cm2, and the benchmark for bioburden could be lowered to < 2-log10 CFU/cm 2, for pump-assisted manual cleaning; however, the ATP benchmark of < 200 RLU was still adequate.
XIII.f.3. The multidisciplinary team should evaluate the need to implement protocols for cleaning verification testing of flexible duodenoscopes with elevator channels. [2: High Evidence]
Duodenoscopes with elevator channels pose a particular challenge for cleaning because of the design of the intricate distal end that provides access to the pancreatic and bile ducts. Even in cases where processing personnel performed all required processing steps, multidrug-resistant microorganisms have been transmitted to patients via flexible endoscopes, resulting in colonization, infection, or death.137,170,171
Alfa et al378 conducted a quasi-experimental study to verify that the ATP benchmark of < 200 RLU was achievable in a busy endoscopy clinic. The researchers sampled all channels from patient-used colonoscopes (n = 20) and duodenoscopes (n = 20) after manual cleaning and tested them for residual ATP. Benchmarks for achieving adequate cleaning were set at ATP < 200 RLU, protein < 6.4 µg/cm2, and bioburden < 4-log10 CFU/cm2. The researchers found that 96% (115 of 120) of manually cleaned endoscopes met the ATP benchmark of < 200 RLU. All 120 endoscopes tested had protein and bioburden levels lower than the benchmark levels. The researchers recommended the use of ATP testing after manual cleaning as an audit tool to confirm adequacy of cleaning. Notably, the five endoscopes that exceeded benchmark levels were duodenoscopes with elevator channels. The researchers suggested these data indicated that the elevator channel required additional monitoring to verify cleaning adequacy.
Bommarito et al390 tested three types of flexible endoscopes (ie, 30 duodenoscopes, 116 gastroscopes, 129 colonoscopes) with ATP at five different hospitals, and determined the number of cleaning failures using < 200 RLU as the benchmark. The researchers observed that the failure rates in the manual cleaning step was highest for duodenoscopes (33%; n = 10) and gastroscopes (24%; n = 28), and lowest for colonoscopes (3%; n = 4). The researchers suggested that a more rigorous protocol was needed for manual cleaning of upper gastrointestinal endoscopes, and cleaning verification testing helped ensure cleaning effectiveness.
XIII.g. A multidisciplinary team that includes infection preventionists, endoscopists, endoscopy processing personnel, microbiologists, laboratory personnel, risk managers, and other involved individuals should evaluate the need to implement a program for regular microbiologic surveillance cultures of flexible endoscopes and mechanical processors. [2: High Evidence]
The collective evidence regarding the need for routine microbiological surveillance cultures is inconclusive. Routine microbiological surveillance culturing of flexible endoscopes after processing, during storage, or before use has not been advised in current US guidelines. The CDC,45 APIC,1 and the “Multisociety guideline on reprocessing flexible endoscopes”44 representing ASGE, the Society for Healthcare Epidemiology of America (SHEA), AORN, and APIC do not recommend routine microbiologic sampling of flexible endoscopes except when focused microbiologic testing is indicated as a result of clinical or epidemiologic findings that suggest endoscopy-related transmission of infection.
A program of regular microbiological surveillance culturing of flexible endoscopes and mechanical processors is advised in the processing guidelines of several international organizations, including the combined Gastroenterological Society of Australia (GESA), Gastroenterological Nurses College of Australia (GENCA), and Australian Gastrointestinal Endoscopy Association (AGEA)15 the combined ESGE and European Society of Gastroenterology and Endoscopy Nurses and Associates (ESGENA) committee,391 and the Steering Group for Flexible Endoscope Cleaning and Disinfection (SFERD).21 However, there are variances among the recommendations.
Routine surveillance microbiological culturing is supported in the literature as an effective method for monitoring the effectiveness and quality of processing, reinforcing best practices, evaluating the effectiveness of corrective interventions, and detecting endoscopes requiring service.93,183,281,367,392–400
Chiu et al401 assessed the effectiveness of mechanical processing of double-balloon enteroscopes by collecting and analyzing samples before and after processing of oral and anal route enteroscopes. Before processing, the positive culture rate was 83.9% (26 of 31) for the oral route enteroscopes, and 100% (26 of 26) for the anal route enteroscopes. After processing, the positive culture rate was 12.9% (four of 31) for the oral route enteroscopes, and 19.2% (five of 26) for the anal route enteroscopes. The researchers concluded that surveillance culture monitoring was an effective method for assessing the effectiveness of HLD of double-balloon enteroscopes.
In a nonexperimental study to evaluate the quality of gastrointestinal endoscope processing and the advantages of microbiological culture surveillance of flexible endoscopes, Saviuc et al393 conducted a retrospective analysis of the results of endoscope sampling performed from October 1, 2006, to December, 31, 2014, in a gastrointestinal unit of a French teaching hospital equipped with 89 flexible endoscopes and three mechanical processors. The compliance rate was defined as the proportion of results that met target (< 5 CFU and absence of indicator microorganisms) and alert (≤ 5 to ≤ 25 CFU and absence of indicator microorganisms). Indicator microorganisms included Enterobacteriaceae, Pseudomonas, S maltophilia, S aureus, Acinetobacter, and Candida. A total of 846 samples were taken, and the researchers found the overall compliance rate was 86% (n = 728). A total of 14% (n = 118) samples carried indicator microorganisms. The researchers concluded that microbiological surveillance was indispensable for monitoring processing, reinforcing good practices, and detecting endoscopes in need of service.
Bisset et al402 monitored patient-ready endoscopes during an 80-week period to determine the efficacy of decontamination procedures in a busy endoscopy center. The researchers sampled the internal surface of the endoscopes from 1,376 upper gastrointestinal procedures and 987 lower gastrointestinal procedures after mechanical processing. The researchers found that both gastroscopes (1.8%; n = 25) and colonoscopes (1.9%; n = 19) were equally likely to grow bacteria, with all numbers of bacteria < 10 organisms/mL. A change in procedure to processing endoscopes with the buttons attached to the endoscope resulted in a cluster of culture-positive results. No clinically untoward consequences were observed, but the researchers concluded that cultures after changes in protocols were necessary to confirm that the change in protocol did not alter processing effectiveness.
Routine microbiological surveillance may also help to identify the source of contamination and rectify processing methods to prevent transmission of infection.367,394,398,400 Tunuguntla and Sullivan394 performed 300 cultures at three- to six-month intervals on 12 flexible endoscopes between 1994 and 2003. In 1995, they found that all but two endoscopes were culture-positive for Pseudomonas species ranging from 1,000 CFU/mL to 7,000 CFU/mL. The culture-positive endoscopes were reprocessed and recultured, but again were culture-positive for Pseudomonas with CFU ranging from 20,000 CFU/mL to 75,000 CFU/mL. The authors then investigated the water source and mechanical processors and found that one of the processors was culture-positive for 50,000 CFU/mL of Pseudomonas due to a contaminated water source. The contaminated mechanical processor was replaced and the water source was changed, resulting in negative cultures. The authors theorized that these deficiencies in processing might have led to patient infection and would not have been detected except for routine culture surveillance.
Microbiological sampling of rinse water used during mechanical processing may reduce the risk of patient infection or pseudo-infection from waterborne bacteria.247
In a literature review to determine the need for microbiological culturing of rinse water used in mechanical processors, Muscarella247 discussed the regulatory requirement403,404 and recommendations45,77,256 for validating the sterilization process using biological indicators to ensure that conditions for sterilization have been achieved and the similar need for verifying that utility water passed through water filtration systems, such as those connected to mechanical processors used for flexible endoscopes, is cultured. The filtered water used to rinse the endoscope may be labeled “sterile” or “bacteria free”; however, there is no way to know whether the rinse water actually meets this claim if it is not routinely sampled. Routine sampling of the rinse water may also provide information about the effectiveness of the water filtration system.
Endoscopes are complex devices. There may be debris and bacterial growth in inaccessible portions of the endoscope. Viruses such as hepatitis B and C and HIV cannot be cultured using standard methods.138 Commonly used disinfectants may inhibit cultures. There may be false-positive results from contaminated equipment or skin. A negative culture does not guarantee that the scope has been adequately processed. Surveillance cultures of processed endoscopes have not been validated by correlating viable counts on an endoscope with infection after an endoscopic procedure.44,45 Notably, the false-positive rate, the false-negative rate, and the limits of detection also have not been established.138 The sensitivity of routine cultures may be unreliable for detecting the organisms associated with outbreaks.
Between May and November 2013, three patients at a Wisconsin medical center were identified as having NDM-1 carbapenem-resistant E coli after undergoing ERCP procedures with the same duodenoscope. Smith et al174 observed the endoscope processing procedures and found no lapses. The investigators obtained three cultures from the duodenoscope: one sonication culture, one brush culture with the elevator channel open, and one brush culture with the elevator channel closed. Despite these measures, the duodenoscope was culture-negative; however, the evidence was sufficiently strong to implicate the duodenoscope as the mode of transmission. The investigators concluded that it was questionable whether routine surveillance cultures would have led to an earlier identification of endoscope colonization since the NDM-1-producing E coli was not able to be isolated from the implicated duodenoscope.
Kola et al146 reported an outbreak of CRKP in a German university hospital associated with a contaminated duodenoscope. Between December 2012 and January 2013, CRKP was cultured from 12 patients staying on four different wards. Molecular typing confirmed the close relation between all 12 isolates. Six of the patients were from the same ward; they were immediately transferred to separate rooms and placed on contact precautions. The remaining six patients had all undergone ERCP procedures using the same duodenoscope. Culturing of the duodenoscope did not recover CRKP. The investigators reviewed processing procedures for the duodenoscope and could find no deviations from the manufacturer’s IFU; however, they did obtain positive cultures for Enterococci, which they suggested was indicative of insufficient cleaning. The investigators concluded that although culturing of the duodenoscope did not recover CRKP, it did not exclude it as the vehicle of transmission. They theorized that flushing the channels with normal saline may not have been sensitive enough to reveal the contamination, particularly after the endoscope had been processed several times before sampling, as it was in this case.
Fraser et al405 conducted a case-control study following an outbreak of multidrug-resistant P aeruginosa sepsis in five patients who underwent ERCP procedures with the same duodenoscope. The endoscope, which was on loan from the manufacturer, had been processed and cultured with negative results one month earlier before being put into clinical use. The investigators concluded that the organism that caused the outbreak had most likely been transmitted from patient to patient by the loaned endoscope. In an attempt to prevent such an outbreak, endoscopes at the facility had been cultured quarterly before the outbreak; however, the outbreak occurred despite a negative surveillance culture of the implicated endoscope. The investigators suggested that routine cultures were not helpful in preventing the outbreak and were therefore of no benefit. They theorized that the endoscopist's awareness of the potential for opportunistic infection following ERCP procedures was more valuable than routine endoscope surveillance cultures.
The use of surveillance cultures is confounded by the delay in feedback and the frequent isolation of nonpathogenic organisms resulting from environmental contamination.44,93 The need to quarantine flexible endoscopes until the culture results have been obtained may not allow for rapid reuse of the tested endoscope and could also lead to delays in patient care.138
Microbiological culturing is resource-intensive, and requires additional expenditures for microbiological testing and time for personnel to collect and process samples.138,367,406 Culturing for bacterial load is impractical for many endoscopy centers that may not have access to microbiology laboratories.138 Implementing a recommendation for routine surveillance cultures may require that some facilities outsource culture testing to qualified microbiologists. This could be quite costly, and it might also be difficult for facilities to find a laboratory that is willing to perform the necessary culture testing. Outsourcing surveillance culturing to environmental or contract laboratories may also lead to uncertainty in interpretation of results.138
Gillespie et al407 conducted a review of microbiological testing conducted between January 1, 2002, and December 31, 2006, at two health campuses in Southern Australia in which, together, more than 3,500 endoscopic procedures were performed annually. Bronchoscopes, duodenoscopes, and mechanical processors were microbiologically sampled every four weeks. Gastroscopes and colonoscopes were cultured every three months. Positive cultures were investigated and followed up by the endoscopy and infection prevention teams. Costs for processing team members to sample the endoscopes were calculated at weekend pay rates because the samples were obtained outside of normal operating hours. Time to sample was calculated at 22 minutes per sample and $10.54 ($AUD 15) per hour. During the five-year period, 2,374 microbiological tests were undertaken. The annual cost of microbiological testing was $14,109.55 ($AUD 20,080). The total cost of testing over five years was $70,547.75 ($AUD 100,400). In 2015, this would equate to a sampling cost of $12.53 ($AUD 17.83) per hour, an annual cost of $83,885.55 ($AUD 119,369.14), and a five-year cost of $419,427.75 ($AUD 596,845.70).
XIII.g.1. The multidisciplinary team should establish the methods and frequencies for microbiological surveillance culturing of flexible endoscopes and mechanical processors. [2: High Evidence]
Standards for performing microbiological cultures, including the frequency of testing and the interpretation of results have not been determined.44,45,93,183,367,399 A protocol for culturing and a sampling method has not yet been validated.93,399 Different techniques may be required for different portions of the endoscope. For example, a swab-rinse technique may be recommended for sampling exterior surfaces and the distal opening of the suction/biopsy channel port.93 A flush/brush/flush technique with rinsing through the channels using a sterile fluid and sterile cleaning brush to obtain samples through the biopsy port may be recommended for sampling the interior surface of the endoscope channels.93 A flush technique may be recommended when brushing the channel lumens is not possible.93
Anterograde sampling, where the last-rinse water from the endoscope is collected inside the mechanical processor at the distal end of the endoscope, or retrograde sampling, where the suction/biopsy channel and the air/water channel are each manually flushed with sterile fluid from the distal to the proximal end, may be recommended.93 Collection of microbiological samples requires the use of sterile technique and this may be difficult when culturing a long, flexible instrument.407 It may be necessary to have more than one person perform the collection to prevent contamination. Developing effective standardized procedures for obtaining the cultures, as well as the actions to be implemented based on the results of the cultures, is challenging.
In a five-year (ie, February 2006 to January 2011) prospective quasi-experimental study to assess the effectiveness of HLD by comparing cultured samples from biopsy channels of gastrointestinal endoscopes and the internal surfaces of mechanical processors, Chiu et al392 collected rinse samples from 420 biopsy channels (ie, 300 gastroscopes, 120 colonoscopes) and swab samples from mechanical processors and examined them for the presence of aerobic and anaerobic bacteria and mycobacteria. The researchers found the number of culture-positive samples obtained from the biopsy channels (13.6%; 57 of 420) was significantly higher than that obtained from the mechanical processors (1.7%; seven of 420). In addition, the number of culture-positive samples obtained from the biopsy channels of gastroscopes (10.7%; 32 of 300) and colonoscopes (20.8%; 25 of 120) was significantly higher than those obtained from the mechanical processors used for HLD of gastroscopes (2.0%; six of 300) and the mechanical processors used for HLD of colonoscopes (0.8%; one of 120).
The researchers concluded that culturing rinse samples from biopsy channels provided a better indication of the effectiveness of HLD of gastrointestinal endoscopes than culturing swab samples from the inner surfaces of mechanical processors. They recommended using rinse samples for performing regular surveillance monitoring of flexible endoscopes. Lu et al408 described the same study but concluded that swab culturing was also a useful method for monitoring the contamination level of the mechanical processor and the effectiveness of the HLD process.392
Because of a severe outbreak of K pneumoniae producing extended-spectrum ß-lactamase that occurred in 16 patients undergoing ERCP procedures in a hospital in France between December 2008 and August 2009, Aumeran et al55 observed duodenoscope processing procedures. They found that the duodenoscopes were not fully dried before they were stored. The investigators hypothesized that bacteria was introduced into the channels of the duodenoscope during the procedures, and despite repeated cleaning and disinfection, the contamination persisted because the moisture remaining in the endoscope channels created conditions favorable to the persistence and growth of the involved organism. The infection was transmitted to 12 patients. Surveillance cultures of the endoscopes were repeatedly negative during the outbreak, but the epidemic strain was finally isolated by flushing and brushing the duodenoscope channels.
In an expert opinion piece, Muscarella409 discussed the limitations of surveillance culturing demonstrated by the Aumeran report55 and the false-negative result that erroneously confirmed the endoscope was safe for patient use. Only when the sampling technique was modified to include brushing of the endoscope’s suction channel in addition to flushing it was the effectiveness of sampling sufficient to culture the outbreak strain. Recovery of bacteria from a sampled channel confirms that the sampling technique effectively recovered microorganisms from the endoscope (ie, a true positive result), whereas non-recovery does not necessarily confirm effective processing.
Recommendations regarding the frequency of surveillance conflict. The ESGEESGENA391 recommends periodic microbiological surveillance of endoscopes, mechanical processors, and the water used in endoscopy concurrently, at intervals no greater than three months.44 The GESA and the GENCA15 recommend sampling of mechanical processors, duodenoscopes, bronchoscopes, and ultrasound instruments at four-week intervals, and sampling of all other gastrointestinal endoscopes at three-month intervals. The SFERD21 recommends microbial testing of water following installation of mechanical processors or water treatment systems, and additionally recommends quarterly testing and testing following incidents or after process-altering repairs. The SFERD recommends annual microbiological culturing of endoscopes and mechanical processors as well as supplemental culturing of loaned endoscopes and culturing of endoscopes and mechanical processors following repair, outbreak, or when deemed necessary by supervisory personnel.
XIII.g.2. The multidisciplinary team should establish benchmarks for microbial levels in flexible endoscope channels and mechanical processors. [3: Moderate Evidence]
Correlations with patients’ clinical outcomes is preferred for validation of benchmarks for microbial levels in flexible endoscope channels; however, this type of validation is difficult to perform. The introduction of low-virulence microorganisms to the gastrointestinal tract does not necessarily mean that the patient will have clinical symptoms or develop an infection. In a non-experimental study to define a realistic benchmark for residual microbial levels that could be achieved 99% of the time in a routine clinical setting, Alfa et al285 tested all channels of 20 flexible gastrointestinal endoscopes (ie, five gastroscopes, nine colonoscopes, six duodenoscopes) used at an endoscopy clinic. The endoscopes were sampled for the presence of bacteria and fungi every Monday morning during a seven-month period. Bacteria and fungi were detected in 5.7% (n = 22) of the 383 channels tested. Of the 141 endoscopes tested, 14.1% (n = 20) had detectable microbial growth in at least one channel. The samples from only two channels grew > 100 CFU/mL of bacteria. The researchers recommended that < 100 CFU/mL be used as a clinically relevant benchmark for the number of bacteria detected from processed endoscopes.
XIII.g.3. The multidisciplinary team should evaluate the need to implement a program for regular microbiological culturing of duodenoscopes.138 [3: Moderate Evidence]
Routine or periodic surveillance culturing may help to assess the adequacy of duodenoscope processing and identify duodenoscopes with persistent contamination despite processing in accordance with the manufacturer’s IFU.138,410
The ECRI recommends performing baseline cultures on all duodenoscope channels and elevator mechanisms using a media specific for carbapenem-resistant Enterobacteriaceae followed by regular surveillance culturing for carbapenem-resistant Enterobacteriaceae as well as quarantining cultured duodenoscopes until negative results are received. The ECRI further recommends that if current resources will not allow for culturing each duodenoscope after each use, weekly culturing may be considered. If cultures are positive, the ECRI recommends reprocessing and repeat culturing, and if the repeat culture is positive, permanently removing the endoscope from service or sending it back to the manufacturer for additional assessment.411
The CDC has provided interim guidance for performing culture surveillance for bacterial contamination of duodenoscopes or other endoscopes that have an elevator mechanism (eg, endoscopic ultrasound) after processing.410,412,413 The CDC guidance is intended to supplement and not replace or modify manufacturer recommended processing procedures.410 The interim protocol provided by the CDC may change as new information becomes available.410
XIII.g.4. Duodenoscopes with positive cultures of ≤ 10 CFU of low-concern organisms should be considered in the context of typical culture results at the facility.410 [3: Moderate Evidence]
Small numbers (< 10 CFU) of low-concern organisms (ie, organisms less often associated with disease and potentially a result of contamination of cultures during collection), such as coagulase-negative staphylococci (excluding Staphylococcus lugdunensis, Bacillus species, and diptheroids) might occasionally be detected. Levels of low-concern organisms can vary depending on the processing procedures in the facility.410
XIII.g.5. Duodenoscopes with positive cultures of any quantity of high-concern organisms should be taken out of service and corrective actions initiated that may include
quarantining the duodenoscope, reprocessing it, and repeating post-processing cultures until it is culture-negative410;
reviewing the manufacturer’s IFU to ensure compliance with processing procedures410;
notifying infection prevention and other relevant personnel to initiate corrective actions, as necessary410;
following the manufacturer’s IFU for having the duodenoscope evaluated for defects410; or
reviewing positive cultures among affected patients to determine whether other clusters of pathogens could have been transmitted.410
[3: Moderate Evidence]
Positive cultures of organisms of high concern (ie, organisms more often associated with disease), such as gram-negative bacteria (eg, E coli, K pneumoniae, Enterobacteriaceae, P aeruginosa), S aureus, and Enterococcus necessitate corrective actions.410
XIII.g.6. If a cluster of suspected or confirmed endoscopy-related infections is identified, the infection preventionist should initiate an investigation in consultation with a health care epidemiologist and the multidisciplinary team.3,12,17 [3: Moderate Evidence]
Initiating an investigation helps determine possible routes of infection and end further transmission.
Weber and Rutala416 proposed a 15-step sequential approach to assist health care facilities in evaluating and managing potential failures of processing semicritical and critical items that includes
confirming failure of processing;
immediately removing from service any potentially incorrectly processed semi-critical or critical item;
not using a questionable mechanical processor until correct functioning has been restored;
informing key stakeholders;
conducting a thorough evaluation to determine the cause of the processing failure;
preparing a list of potentially exposed patients;
assessing whether the processing failure increased the patients’ risk for infection;
informing an expanded list of stake-holders of the processing failure;
developing a hypothesis for the processing failure and initiating corrective action;
developing a method to assess potential adverse patient events;
considering notifying appropriate state and federal authorities;
considering patient notification;
if patients are notified, considering whether they require medical evaluation for possible postexposure therapy with anti-infectives or additional follow-up to detect infection and offering it, if warranted;
developing a detailed plan to prevent similar failures in the future; and
performing an after-action report.
XIII.g.7. If a breach in protocol for endoscope processing is recognized, the infection preventionist, epidemiologist, and multidisciplinary team should perform an assessment and investigation to determine whether patient notification is required, and if so, how patients will be notified and followed.17,78 [3: Moderate Evidence]
Health care facilities have an ethical obligation to inform affected patients in a timely manner when a significant breach in processing occurs.414 Prompt notification allows patients to take precautions to minimize the risk of transmitting the infection to others and allows for early serologic testing.414 Where a breach in processing has been determined to pose a negligible patient risk, health care providers have to consider the ethical issue of a patient’s right to know compared with the potential for causing unnecessary patient distress in a situation where the risk for infection may be very small.414–416 Reporting a processing-related outbreak may also cause patients to avoid potential life-saving endoscopic procedures because of an unwarranted fear of infection.414
XIII.h. Adverse events should be reported and documented according to the health care organization’s policy and procedure and should be reviewed for potential opportunities for improvement. [5: Benefits Balanced with Harms]
Reports of adverse events and near misses can be used to identify actions that may prevent similar occurrences and reveal opportunities for improvement.
XIII.h.1. Near misses (ie, unplanned events that do not result in injury) should be investigated and corrective action taken to prevent serious adverse events. [5: Benefits Balanced with Harms]
XIII.h.2. Reports regarding device malfunction leading to serious injury or death should be submitted to MedWatch: The FDA Safety Information and Adverse Event Reporting Program.418 [5: Benefits Balanced with Harms]
The FDA uses medical device reports to monitor device performance, detect potential device-related safety issues, and contribute to risk-benefit assessments of suspected device-associated deaths, serious injuries, or malfunction. The MAUDE (ie, Manufacturer and User Facility Device Experience) database houses reports submitted to the FDA by mandatory reporters (ie, manufacturers, importers, device user facilities) and voluntary reporters (ie, health care professionals, patients, consumers).418
Mandatory reporters are required to submit reports when they become aware of information that reasonably suggests that one of their marketed devices may have caused or contributed to a death or serious injury or has malfunctioned and that the malfunction of the device would be likely to cause or contribute to a death or serious injury if the malfunction were to recur.418 Voluntary reporters are required to submit reports when they become aware of information that reasonably suggests a device may have caused or contributed to a death or serious injury of a patient.418
Editor’s note: Teflon is a registered trademark of the Chemours Co, Wilmington, DE.
Sharon A. Van Wicklin, MSN, RN, CNOR, CRNFA(E), CPSN-R, PLNC
Senior Perioperative Practice Specialist
AORN Nursing Department
Ramona Conner, MSN, RN, CNOR
Editor-in-Chief, Guidelines for Perioperative Practice
AORN Nursing Department
Cynthia Spry, MA, MS, RN, CNOR(E), CSPDT
New York, New York
The authors and AORN thank Marie A. Bashaw, DNP, RN, NEA-BC, CNOR, Assistant Professor, Wright State University College of Nursing and Health, Dayton, Ohio; Cori L. Ofstead, MSPH, President and CEO, Ofstead & Associates, Inc, St Paul, Minnesota; John E. Eiland, RN, MS, Senior Research Associate, Ofstead & Associates, Inc, St Paul, Minnesota; Judith Goldberg, DBA, MSN, RN, CNOR, CSSM, CHL, CRCST, Director, Patient Care Services, Perioperative and Procedural Services, Lawrence + Memorial Hospital, New London, Connecticut; Sheryl P. Eder, MSN, RN, CNOR, CRCST, Director, Sterile Processing Department, LeeSar Regional Service Center, Fort Myers, Florida; Angela Hewitt, MD, MS, Associate Professor, Division of Infectious Diseases, Associate Medical Director, Department of Infection Control and Epidemiology, Associate Medical Director, Nebraska Biocontainment Unit, Director, Infectious Diseases Outpatient Clinics, University of Nebraska Medical Center, Omaha; Heather A. Hohenberger, BSN, RN, CIC, CNOR, CPHQ, Quality Improvement Consultant, Perioperative Services, Indiana University Health, Indianapolis; and Donna Ford, MSN, RN-BC, CNOR, CRCST, Nursing Education Specialist, Mayo Clinic, Rochester, Minnesota, for their assistance in developing this guideline.
Originally published February 1993, AORN Journal.
Revised November 1997; published January 1998. Reformatted July 2000.
Revised November 2002; published in Standards, Recommended Practices, and Guidelines, 2003 edition.
Reprinted February 2003, AORN Journal.
Revised November 2008; published in Perioperative Standards and Recommended Practices, 2009 edition.
Reformatted September 2012 for publication in Perioperative Standards and Recommended Practices, 2013 edition.
Minor editing revisions made in November 2014 for publication as Guideline for Cleaning and Processing Flexible Endoscopes and Endoscope Accessories in Guidelines for Perioperative Practice, 2015 edition.
Revised February 2016 for publication in Guidelines for Perioperative Practice, 2016 edition.
Minor editing revisions made in October 2016 for publication in Guidelines for Perioperative Practice, 2017 edition.