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Complete Summary

GUIDELINE TITLE

WGO-OMGE practice guideline: endoscope disinfection.

BIBLIOGRAPHIC SOURCE(S)

  • World Gastroenterology Organisation (WGO-OMGE). WGO-OMGE practice guideline: endoscope disinfection. Paris (France): World Gastroenterology Organisation (WGO-OMGE); 2005 Dec 14. 23 p. [15 references]

GUIDELINE STATUS

This is the current release of the guideline.

COMPLETE SUMMARY CONTENT

 
SCOPE
 METHODOLOGY - including Rating Scheme and Cost Analysis
 RECOMMENDATIONS
 EVIDENCE SUPPORTING THE RECOMMENDATIONS
 BENEFITS/HARMS OF IMPLEMENTING THE GUIDELINE RECOMMENDATIONS
 IMPLEMENTATION OF THE GUIDELINE
 INSTITUTE OF MEDICINE (IOM) NATIONAL HEALTHCARE QUALITY REPORT CATEGORIES
 IDENTIFYING INFORMATION AND AVAILABILITY
 DISCLAIMER

SCOPE

DISEASE/CONDITION(S)

Pathogenic organism transmission or infections related to endoscopy

GUIDELINE CATEGORY

Prevention

CLINICAL SPECIALTY

Family Practice
Gastroenterology
Infectious Diseases
Internal Medicine
Pathology
Preventive Medicine

INTENDED USERS

Advanced Practice Nurses
Allied Health Personnel
Hospitals
Nurses
Physician Assistants
Physicians
Public Health Departments

GUIDELINE OBJECTIVE(S)

To provide practice guidelines for endoscope disinfection

TARGET POPULATION

Patients undergoing endoscopy

INTERVENTIONS AND PRACTICES CONSIDERED

  1. Endoscope cleaning using ultrasonic techniques, detergents
  2. Endoscope disinfection using disinfectants (e.g., glutaraldehyde, orthophthalaldehyde, peracetic acid, electrolyzed acid water); manual disinfection; automatic reprocessing
  3. Endoscope sterilization and storage
  4. Personnel training

MAJOR OUTCOMES CONSIDERED

  • Safety and efficacy of endoscopic disinfection
  • Incidence of pathogen transmission

METHODOLOGY

METHODS USED TO COLLECT/SELECT EVIDENCE

Hand-searches of Published Literature (Primary Sources)
Searches of Electronic Databases

DESCRIPTION OF METHODS USED TO COLLECT/SELECT THE EVIDENCE

World Gastroenterology Organization's (WGO's) Graded Evidence System

WGO's Grading Evidence System is built to help National Societies of Gastroenterology and all those interested in the practice and research of gastroenterology keep track of the literature in topics covered by WGO Guidelines.

Evidence is classified into three categories:

  • Systematic reviews, consensus statements, meta-analyses, evidence-based practice guidelines
  • Clinical trials
  • Other reading

The following journals are scanned for new evidence:

  • Gastroenterology
  • Annals of Internal Medicine
  • Hepatology
  • GUT
  • Journal of Hepatology
  • Alimentary Pharmacology & Therapeutics
  • American Journal of Gastroenterology
  • Inflammatory Bowel Disease
  • Gastrointestinal Endoscopy
  • Journal of Pediatric Gastroenterology & Nutrition
  • Digestion
  • Scandinavian Journal of Gastroenterology
  • European Journal of Gastroenterology and Hepatology
  • Digestive Diseases and Sciences
  • Endoscopy
  • Journal of Gastroenterology and Hepatology
  • Digestive Surgery
  • Digestive Diseases

Plus a selection from the general journals:

  • New England Journal of Medicine
  • JAMA
  • Lancet
  • BMJ
  • Nature
  • Science

Coverage

Graded Evidence is an iterative process—and for that reason need not be so concerned with searching both Medline, Embase and Biosis for example. All top gastrointestinal (GI) journals are covered by both Medline and Embase and in single one-off complex searches unique citations in one or the other are often due either to differences in database currency or differences in coverage of less important journals. In addition to cost issues, the generous republishing and copyright policies of the US National Library of Medicine (NLM) make Medline the preferred choice.

Search Strategies

Search strategies for each topic are based on a combination of controlled access and free text terms. The strategies aim for "precision" rather than "sensitivity." Busy gastroenterologists probably prefer very precise search strategies in top GI journals and thus make sure every major article is found. The WGO Graded Evidence works along the lines of PUBMED Medline "Clinical queries" features. Precise searches only find relevant information. Indexing errors may still be responsible for irrelevant or duplicate records. Case studies and animal studies are not usually included.

Finding Evidence

True evidence-based searches require a deeper understanding of databases and search strategies not necessary for our purpose. WGO Global Guidelines are not systematic reviews. The WGO Library adheres to the Cochrane Collaboration's views that a searcher has to work through a hierarchy of evidence as follows.

As you move down the hierarchy you are more likely to find "opinion" instead of evidence.

NUMBER OF SOURCE DOCUMENTS

  • 4 meta-analyses, systematic reviews, and practice guidelines
  • 9 other readings

METHODS USED TO ASSESS THE QUALITY AND STRENGTH OF THE EVIDENCE

Expert Consensus

RATING SCHEME FOR THE STRENGTH OF THE EVIDENCE

Not applicable

METHODS USED TO ANALYZE THE EVIDENCE

Review
Review of Published Meta-Analyses

DESCRIPTION OF THE METHODS USED TO ANALYZE THE EVIDENCE

Not stated

METHODS USED TO FORMULATE THE RECOMMENDATIONS

Not stated

RATING SCHEME FOR THE STRENGTH OF THE RECOMMENDATIONS

Not applicable

COST ANALYSIS

A formal cost analysis was not performed and published cost analyses were not reviewed.

METHOD OF GUIDELINE VALIDATION

Not stated

DESCRIPTION OF METHOD OF GUIDELINE VALIDATION

Not applicable

RECOMMENDATIONS

MAJOR RECOMMENDATIONS

Endoscope Cleaning

General Procedures

Endoscope cleaning consists of the mechanical cleaning of internal and external surfaces. This includes brushing and flushing of internal channels with sterile, filtered or drinking-quality water and detergent.

Preliminary cleaning should be started before the endoscope is detached from the light source/videoprocessor. As soon as the endoscope has been removed from the patient begin reprocessing, observing the following steps:

  • clear gross debris by sucking detergent through the working channel (250 ml/min)
  • ensure the working channel is not blocked
  • irrigate the air and water channels with water checking for blockages
  • expel any blood, mucus or other debris
  • wipe down the insertion shaft
  • check for bite marks or other surface irregularities
  • detach the endoscope from the light source/videoprocessor
  • transfer the endoscope to a reprocessing room with atmospheric extraction facilities
  • conduct a leakage test daily to check the integrity of all channels before reprocessing

The next stage involves the dismantling of detachable parts of the endoscope whereby valves and water bottle inlets are removed and detachable tips taken off the insertion tube. Rubber biopsy valve caps are discarded if breached. Water bottles and suction/air-water valves should be autoclaved.

All exposed internal and external surfaces should then be manually cleaned and rinsed according to the following recommendations:

  • use a low-foaming detergent specifically designated for medical instrument cleaning
  • use the appropriate dilution according to the manufacturer's instructions
  • flush and brush all accessible channels to remove all organic (e.g. blood, tissue) and other residues with a disposable brush-tipped wire designed for this purpose
  • use brushes of the appropriate size for the endoscope channel, parts, connectors and openings; bristles should have contact with all surfaces
  • repeatedly actuate the valves during cleaning to facilitate access to all surfaces
  • clean the external surfaces and components of the endoscope with a soft cloth, sponge or brush
  • subject reusable endoscopic accessories and endoscope components to ultrasonic cleaning to remove material from hard-to-clean areas
  • dispose of all cleaning items

If some of the above steps are not feasible due to limited resources, consider the following alternatives:

  • cleaning with a non-enzymatic detergent
  • cleaning very carefully with soap and water of acceptable quality as the minimum standard
  • using sterile, filtered, drinking-quality or boiled water

Do not use tap water unless it is of drinking-water quality.

Ultrasonic Cleaning

Ultrasonic cleaning of reusable endoscopic accessories and components may be needed to remove material from hard-to-clean areas. The same detergent must be used for ultrasonic cleaning as for manual cleaning. The recommendations are as follows:

  • a non-foaming detergent should be used which is appropriate for both manual cleaning and ultrasonic cleaning
  • enzymatic detergent solutions should preferably be used
  • the specific contact time recommended by the manufacturer for enzymatic detergents should be observed
  • inhalation of enzyme-containing detergent aerosols and thus the risk of anaphylactic reactions should be minimized by covering the detergent container

Detergents

For the cleaning of endoscopes detergents with or without enzymes, and detergents containing antimicrobial substances may be used. Use of non-foaming detergents is recommended. Foaming can inhibit good fluid contact with device surfaces, and prevent a clear field of vision during the cleaning process with a risk of injury to personnel.

The detergent selected should effectively loosen organic and non-organic material so that the flushing action of the detergent fluid and subsequent rinsing water removes the unwanted material.

Detergents may contain the following substances with properties supporting the cleaning action:

  • surfactants which reduce surface tension thus facilitating removal of debris
  • activated H2O2 which effectively loosens debris at room temperature
  • proteases which break protein debris into smaller, more soluble subunits
  • amylase which catalyses the breakdown of starch
  • lipase which breaks up fat-containing debris
  • quaternary ammonium compounds, biguanidine, alcohols or aldehydes

Other active substances recommended for cleaning include amine compounds or glucoprotamine, peracetic acid and hydrogen peroxide.

Detergents containing aldehydes should not be used for cleaning as they denature and coagulate protein. Likewise detergents based on amine compounds or glucoprotamine in combination with glutaraldehyde for disinfection should not be used as chemical reactions may result in formation of colored residues.

Enzymatic detergents should be discarded after each use as these products are not microbicidal and will not retard microbial growth. In Europe detergents commonly used may contain antimicrobial substances which reduce the risk infection to reprocessing personnel, but they do not replace disinfection.

Enzymes generally function more effectively at temperatures above room temperature (>20-22°C) and should be used in accordance with the manufacturer's recommendations.

Endoscope Disinfection

General Procedures

Disinfection of endoscopes should be performed in dedicated rooms by trained staff at the beginning and at the end of each patient list, as well as between patients. The European practice of disinfecting endoscopes just before patient use is not always practiced or recommended in other countries. However, reprocessing the endoscope immediately after use is a commonly accepted standard. An exception can be made when the endoscope is stored in a clean environment.

Recommendations for effective disinfection with a liquid chemical germicide include:

  • using an automatic endoscope reprocessor
  • performing disinfection in a dedicated area with atmospheric extraction facilities
  • flushing high-level disinfectant or chemical sterilant throughout the endoscope at the correct temperature and for the correct duration
  • concluding disinfection by rinsing with sterile or filtered water or alcohol
  • drying each endoscope properly with forced air

For the protection of staff during the disinfection procedure the following apparel or equipment is recommended:

  • long-sleeved waterproof gowns which are changed between patients
  • gloves long enough to cover the forearms
  • goggles to prevent conjunctival irritation and protect from splashes
  • disposable charcoal-impregnated face masks to reduce inhalation of vapor
  • an approved vapor respirator available for spillage or other emergencies

There are various classes of disinfectants available. Chemical sterilants are strong disinfectants that kill all microorganisms, including spores, after prolonged exposure; the exposure times recommended by the manufacturer and in the scientific literature should be adhered to. After shorter exposure periods of up to 45 minutes chemical sterilants kill all microorganisms except large numbers of bacterial spores.

Other disinfectants may be biocidal for mycobacteria, vegetative bacteria, most viruses and most fungi, but do not necessarily kill bacterial spores. Some disinfectants kill most vegetative bacteria, some fungi and some viruses within 10 minutes.

Germicides differ markedly among themselves primarily in their antimicrobial spectrum and rapidity of action.

It is important to note that an alcohol flush should not be used as an alternative to disinfection as alcohol is expensive and hazardous to use.

Disinfectants

The ideal disinfectant is effective against a wide range of organisms, including blood-borne viruses and prion proteins; compatible with endoscopes, accessories and endoscope reprocessors; non-irritant and safe for users; and permits environmentally friendly disposal.

Disinfectants must be used at the correct temperature, and in accordance with the manufacturer's instructions and current recommendations in the literature. The disinfectants should be tested regularly with test strips and/or kits provided by manufacturers to ensure optimal activity of the products.

Factors influencing the choice of disinfectant include:

  • dilution process
  • stability of the solution
  • number of reuses possible
  • direct cost
  • indirect costs (e.g., appropriate automatic endoscope reprocessor, storage space, conditions for use, staff protection measures)

Refer to Section 5.3 of the original guideline document for a detailed discussion of the advantages and disadvantages of specific disinfectants, including glutaraldehyde, orthophthalaldehyde (OPA), peracetic acid, electrolyzed acid water (EAW).

Manual Disinfection

In manual disinfection the endoscope and endoscope components should be completely immersed in high-level disinfectant/sterilant, ensuring that all channels are perfused. (Any non-immersible gastrointestinal endoscopes should already have been removed from circulation.) At least once a day the water bottle and its connecting tube should be sterilized - these are used for cleaning the lens and irrigation during endoscopy. If possible, the water bottle should be filled with sterile water.

The value of simple soap and water should not be overlooked.

Automatic Reprocessing

In automatic endoscope reprocessing (AER) the endoscope and endoscope components are placed in the reprocessor, and all channel connectors attached according to AER and endoscope instructions. AER ensures exposure of all internal and external surfaces to a disinfectant or chemical sterilant. If an AER cycle is interrupted, disinfection or sterilization cannot be assured and the entire process should be repeated.

Refer to Section 5.5. of the original guideline document to see bulleted lists of the advantages and disadvantages of automatic reprocessing compared to manual reprocessing.

Careful maintenance is the key to effective and safe automatic reprocessing.

Water used for rinsing in automatic endoscope reprocessors should be maintained free of microorganisms and other particles by means of bacterial filters, biocides or other methods. If the local supply delivers hard water, water softeners should be used. Samples of final rinse water from the automatic reprocessor should be subjected to microbiological testing at least weekly.

Importance of Rinsing and Drying

Endoscopes are generally not dried between consecutive examinations. The drying process is designed to prevent growth of microorganisms during storage. The final drying steps greatly reduce the possibility of recontamination of the endoscope with waterborne microorganisms. Alcohol drying can be hazardous. It should be noted that in many guidelines an alcohol flush for drying is considered unnecessary if the drying process is carried out properly.

The recommended steps are as follows:

  • after disinfection, rinse the endoscope and flush the channels with water to remove the disinfectant/sterilant
  • discard the rinse water after each use/cycle
  • flush the channels with 70-90% ethyl alcohol or isopropyl alcohol
  • dry with compressed air

The disinfectant or chemical sterilant must be rinsed from the internal and external surfaces of the endoscope. If tap water is used, a flush with 70% alcohol should be performed. Caution is necessary using alcohol due to the risk of explosion.

Sterilization

Sterilization is used primarily for processing endoscope accessories and is accomplished by either physical or chemical methods. It is important to note that the term 'sterilization' should not be equated with 'disinfection', and that there is no such state as 'partially sterile'.

Steam under pressure, dry heat, ethylene oxide gas, hydrogen peroxide, gas plasma, and liquid chemicals are the principal sterilizing methods used in healthcare facilities. When chemicals are used for the purpose of destroying all forms of microbiological life, including fungal and bacterial spores, they are referred to as chemical sterilants. These same germicides may also be used for shorter exposure periods in the disinfection process (high-level disinfection).

Flexible endoscopes do not tolerate high processing temperatures (> 60°C) and cannot be autoclaved or disinfected using hot water or subatmospheric steam. They may be sterilized, however, provided they have been thoroughly cleaned and the manufacturer's processing criteria are fulfilled. Although the value of sterilization would seem to be obvious, there is no evidence available indicating that sterilization of flexible endoscopes improves patient safety by reducing the risk of transmission of infection.

Accessories

Disposable accessories should not generally be used more than once. If they are to be used more than once due to limited resources, it is imperative that they are subjected to a complete cleaning, disinfection and sterilization cycle between each use. The steps involved are summarized as follows:

dismantle → brush → flush → dry

Good quality water (sterile, filtered or drinking-quality) and a disinfectant solution, or at least a soap detergent, should be used.

  • Consider whether legal implications allow re-use
  • If local regulations allow reuse, arrange for reprocessing with optimal efficacy
  • Consider the implications for manufacturer guarantees

Endoscopic accessories that penetrate the mucosal barrier (e.g. biopsy forceps, guidewires, cytology brushes, other cutting instruments) should be either used once only or cleaned ultrasonically or mechanically and then sterilized or autoclaved between each patient use. Endoscope accessories that are not passed through the working channel of the endoscopes (such as water bottles and bougies) are normally reusable and should be autoclaved for 20 minutes at 134°C. Rubber valves should be changed after the passage of biopsy forceps, guidewires and/or other accessories.

Endoscope Storage

Colonized water or residual moisture can be a source of microorganisms, and proper drying will remove any moisture from internal and external surfaces of the endoscope. Drying of endoscopes especially prior to prolonged storage decreases the rate of bacterial colonization. Forced air drying adds to the effectiveness of the disinfection process.

The following are recommendations for storage:

  • ensure proper drying prior to storage
  • hang preferably in a vertical position to facilitate drying
  • remove caps, valves and other detachable components according to the manufacturer's instructions
  • uncoil insertion tubes
  • protect endoscopes from contamination by placing a disposable cover over them
  • use a well ventilated room or cabinet for reprocessed endoscopes only
  • clearly mark which endoscopes have been reprocessed

It is important to avoid contamination of disinfected endoscopes by contact with the environment or by prolonged storage in an area that may promote pathogen growth. Special storage cabinets are available that decrease the risk of post-disinfection contamination.

Quality Assurance

Personnel Training

All healthcare personnel in an endoscopy unit should receive training in standard infection control measures, including those designed to protect both patients and healthcare workers.

CLINICAL ALGORITHM(S)

None provided

EVIDENCE SUPPORTING THE RECOMMENDATIONS

TYPE OF EVIDENCE SUPPORTING THE RECOMMENDATIONS

The type of evidence supporting the recommendations is not specifically stated for each recommendation.

BENEFITS/HARMS OF IMPLEMENTING THE GUIDELINE RECOMMENDATIONS

POTENTIAL BENEFITS

Prevention of pathogenic organism transmission during endoscopy and the subsequent development of infection

POTENTIAL HARMS

Adverse effects of disinfectants

IMPLEMENTATION OF THE GUIDELINE

DESCRIPTION OF IMPLEMENTATION STRATEGY

An implementation strategy was not provided.

IMPLEMENTATION TOOLS

Foreign Language Translations

For information about availability, see the "Availability of Companion Documents" and "Patient Resources" fields below.

INSTITUTE OF MEDICINE (IOM) NATIONAL HEALTHCARE QUALITY REPORT CATEGORIES

IOM CARE NEED

Staying Healthy

IOM DOMAIN

Effectiveness
Safety

IDENTIFYING INFORMATION AND AVAILABILITY

BIBLIOGRAPHIC SOURCE(S)

  • World Gastroenterology Organisation (WGO-OMGE). WGO-OMGE practice guideline: endoscope disinfection. Paris (France): World Gastroenterology Organisation (WGO-OMGE); 2005 Dec 14. 23 p. [15 references]

ADAPTATION

Not applicable: The guideline was not adapted from another source.

DATE RELEASED

2005 Dec 14

GUIDELINE DEVELOPER(S)

World Gastroenterology Organisation - Medical Specialty Society

SOURCE(S) OF FUNDING

World Gastroenterology Organisation (WGO-OMGE)

GUIDELINE COMMITTEE

Guidelines Committee

COMPOSITION OF GROUP THAT AUTHORED THE GUIDELINE

Committee Members: M. Fried, Switzerland (Chairman); G. Krejs, Austria (Vice-Chairman); R. Allan, UK; F. Bazzoli, Italy; D. Bjorkman, USA; D. Chen, Taiwan; A. Elewaut, Belgium; M. Farthing, United Kingdom; S. Fedail, Sudan; J. Garisch, South Africa; A. Gangl, Austria; S. Hamid, Pakistan;  J. Heathcote, Canada; R. Hunt, Canada; Y. Hutin, WHO, Switzerland; D. LaBrecque, USA; S.K. Lam, Hong Kong; D. Lavanchy, WHO, Switzerland; G. Lindberg, Sweden; P. Malfertheiner, Germany; J. Malagelada, Spain; R. Saenz-Fuenzalida, Chile; N. Sato, Japan; M. Shah, Kenya; P. Sharma, USA; J. Sollano, Phillippines; O.O. Thomsen, Denmark; A. Thomson, Canada; H. Yu Liu, China; N. Vakil, USA

Ex Officio Members: G.N.J. Tytgat (or Vice President); H. Cohen (or his Deputy); J. Geenen (or his Deputy)

Review Team: Professor J F Rey (co-chairman), France; Professor D Bjorkman (co-chairman), USA; Mrs D Duforest-Rey, France; Professor A Axon, United Kingdom; Professor R Saenz, Chile; Professor M. Fried, Switzerland; Professor T Mine, Japan; Professor K Ogoshi, Japan; Dr. J.H. Krabshuis

FINANCIAL DISCLOSURES/CONFLICTS OF INTEREST

Not stated

GUIDELINE STATUS

This is the current release of the guideline.

GUIDELINE AVAILABILITY

Electronic copies: Available from the World Gastroenterology Organisation (WGO-OMGE) Web site.

Print copies: Available from the World Gastroenterology Organisation (WGO-OMGE), c/o Medconnect GMBH, Brünnsteinster. 10, 81541 Munich, Germany

AVAILABILITY OF COMPANION DOCUMENTS

PATIENT RESOURCES

None available

NGC STATUS

This NGC summary was completed by ECRI on May 3, 2007.

COPYRIGHT STATEMENT

The copyright of these Guidelines is retained by WGO-OMGE. Users may download or print copies for their own use and may photocopy guidelines for the purpose of producing local protocols. However, republishing any guideline or part of any guideline, in any form, without specific authorisation from WGO-OMGE is specifically prohibited. Permission to reproduce or republish WGO-OMGE Guidelines or excerpts from Guidelines can be obtained from MEDCONNECT, WGO-OMGE Executive Secretariat, Brünnsteinstraße 10, 81514 Munich, Germany. WGO-OMGE does not endorse in any way derivative or excerpted materials based on these Guidelines and it cannot be held liable for the content or use of any such adapted products. Although every effort has been made to ensure the accuracy and completeness of these electronic WGO-OMGE Guidelines, WGO-OMGE cannot accept any responsibility for errors or omissions and assumes no responsibility or liability for loss or damage resulting from the use of information contained in these Guidelines.

DISCLAIMER

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