Copyright ©2014 Baishideng Publishing Group Inc.
World J Gastrointest Endosc. Sep 16, 2014; 6(9): 390-406
Published online Sep 16, 2014. doi: 10.4253/wjge.v6.i9.390
Table 1 Typical sequence of steps for manual and automatic reprocessing of flexible endoscopes including the typical duration of the various cleaning steps
Manual processingAutomatic processing
Pre-cleaning the outer surface with a detergent-soaked single-use gauze and rinsing all channels with the cleaning agent, usually for 2 min
Brush-cleaning all accessible channels with a suitable brush, usually for 3 min
Chemical cleaning; filling all channels with the cleaning agent, allowing the cleaning agents to persist inside the channel for approximately 5 min
Rinsing, usually for 1 min
Final rinsing
Table 2 Outbreaks and pseudo-outbreaks reported in connection with biofilm or peracetic acid-based processing of flexible endoscopes
Number/type of infection(s)Pathogen(s)Type of endoscopic procedureReason for outbreak / pseudo-outbreakPeracetic acid-based formulations were used forRef.
None (pseudo-outbreak)Pseudomonas aeruginosaGastroscopy, bronchoscopySuboptimal duration of glutaraldehyde application during disinfection; “resistance” to glutaraldehyde may have been enhanced by manual cleaning with peracetic acid-based disinfectant[214]Cleaning step[202]
2: infection (not further specified)3: colonizationOXA-48 Klebsiella pneumoniaeBronchoscopyA problem with the washer disinfector or the cleaning procedure was assumed as the reasonCleaning step and disinfection step (Gastmeier P, personal communication)[203]
4: pneumonia (3 cases); colonization (1 case)MDR Pseudomonas aeruginosaGastroscopyInsufficient initial cleaning, shortening of the immersion time and brushing time, insufficient channel flushing, and inadequate drying prior to storageDisinfection step[124]
4: bacteraemia, biliary tract infection, respiratory tract infection9: colonisationKPC-2 Klebsiella pneumoniaeDuodenoscopyContaminated duodenoscope; reason for outbreak: inadequate cleaningDisinfection step[204]
8: bloodstream infection4: biliary tract infection4: colonizationESBL Klebsiella pneumoniae (CTX-M-15)ERCPInsufficient manual cleaning, insufficient drying after processingDisinfection step[125]
3: sepsisPseudomonas aeruginosaERCPPresence of biofilm on undamaged channelsDisinfection step (Kovaleva J; personal communication)[205]
5: infection (not further specified) 9: colonizationOXA-48 Klebsiella pneumoniaeDuodenoscopyOne endoscope had probably a defect resulting in insufficient disinfectionDisinfection step (Gastmeier P, personal communication)[203]
18: pulmonary infection (4 cases, one of them died); colonization (14 cases)Imipenem-resistant Pseudomonas aeruginosaBronchoscopyIncorrect connectors joining the bronchoscope suction channel to the STERIS SYSTEM 1 processor“Automatic processing”[206]
2: bacteremia and biliary tract infection 4: colonizationKPC-2 Klebsiella pneumoniaeGastroscopyDelayed pre-wash resulting in drying of the gastroscope; short drying period after the peracetic acid treatment resulting in incomplete drying“Wash”[207]
Table 3 Adverse effects after processing with peracetic acid after endoscopy
Number of casesType of reactionPossible explanationRef.
10ColitisUnclear, reprocessing with PAA, but afterwards channels were flushed with hydrogen peroxide[210]
1ColitisPAA residues in the biopsy suction channel[215]
2ColitisDefect of automatic rinsing of a channel[216]
1ColitisChannel not flushed[217]
1ColitisInadequate rinsing of a channel[212]
No number providedPseudolipomatosisAir channels not rinsed[218]
4ColitisProgramming error in the automatic disinfection device, related to the air/water channels[219]
12Colonic mucosal pseudolipomatosisRinsing was not done as recommended[220]
Table 4 Overview of evidence-based guidelines for processing flexible endoscopes, focusing on the use of peracetic acid during the cleaning step
InstitutionGuidelinesYearUse of peracetic acid for cleaning
AORNRecommended practices for cleaning and processing endoscopes and endoscope accessories[221,222]2012No recommendation
APICAPIC guidelines for infection prevention and control in flexible endoscopy. Association for Professionals in Infection Control[223]2000No recommendation
APSICThe ASEAN Guidelines for disinfection and sterilization of instruments in health care facilities[224]2012No recommendation
ASGEMultisociety guidelines on reprocessing flexible gastrointestinal endoscopes: 2011[225,226]2011No recommendation
BC Ministry of HealthBest Practice Guidelines For Cleaning, Disinfection and Sterilization of Critical and Semi-critical Medical Devices[227]2011No recommendation
BSGBSG Guidelines for Decontamination of Equipment for Gastrointestinal Endoscopy[228]2008No recommendation
CDCGuidelines for Disinfection and Sterilization in Healthcare Facilities, 2008[229]2008No recommendation
ESGE/ESGENA1ESGE/ESGENA Technical Note on Cleaning and Disinfection[230]2003Recommended
ESGE/ESGENAESGE-ESGENA guideline: Cleaning and disinfection in gastrointestinal endoscopy, update 2008[231]2008No recommendation
HPSEndoscope Reprocessing: Guidance on the Requirements for Decontamination Equipment, Facilities and Management[232]2007No recommendation
JGETSGuidelines for cleaning and disinfecting endoscopes - Second edition[233]2004No recommendation
Public Health Agency of CanadaInfection Prevention and Control Guideline for Flexible Gastrointestinal Endoscopy and Flexible Bronchoscopy[234]2010No recommendation
RKI2Hygiene requirements for reprocessing of medical devices[235]2001No recommendation
RKIHygiene requirements for reprocessing of medical devices[236]2012Not recommended
SGNAStandards of Infection Control in Reprocessing of Flexible Gastrointestinal Endoscopes[237]2013No recommendation
WGO/OMEDWGO/OMED Practice Guideline Endoscope Disinfection[238]2005Recommended
WGO/WEOEndoscope disinfection - a resource-sensitive approach[239]2011No recommendation
Table 5 Effects and possible outcomes of peracetic acid use for cleaning flexible endoscopes
Characteristic, reason for cleaning stepEffect of peracetic acidPossible outcome, compared with classical cleaning
Removal of biofilmVariable1Insufficient removal of biofilm
Fixation of biofilmPossible1Fixation of biofilm to variable degrees
Removal of dried bloodPartial removal1Insufficient removal of dried blood
Fixation of dried bloodVery likelyFixation of dried blood to variable degrees
Fixation of brain tissueVery likelyStrong fixation of nerve tissue, including prions
Adaptation of microorganisms surviving the cleaning stepLikely, especially in gram-negative bacteriaInsufficient efficacy of disinfection step, persistence of pathogens, beginning of biofilm formation
Cross-resistance to other biocidal compounds as a result of exposure to sublethal peracetic acid concentrationsPossibleInsufficient efficacy of disinfection step, persistence of pathogens, beginning of biofilm formation
Table 6 Practical tips to ensure optimal cleaning of flexible endoscopes
Clinical practice tipMajor advantageRef.
Clean promptly after useNo drying of organic material such as blood[77,207]
Follow the instructions of the endoscope manufacturer as closely as possible (e.g., type of brush or cleaning adapter)Optimum cleaning of an entire channel
Prefer washer disinfectors with a monitoring system indicating channel blockageA blocked channel cannot be cleaned adequately and is immediately identified; targeted brush cleaning may be necessary
Do not switch off the monitoring system for detection of blocked channelsChannels may be blocked and inadequately cleaned; personnel may not detect blocked channels with all possible implications for patient safety
Support by gastroenterologistIt is strongly recommended that the clinician fully understands the cleaning and disinfection steps and does not inhibit his or her staff's ability to perform them correctly[240]
Allow external audits by local health authorities on the quality of processing including cleaningImplementation of guidelines may be more successful if the local health authorities visit the endoscopy units and compare current practices with the relevant guidelines. This effect seems to be more easily achieved in in-patient rather than in out-patient endoscopy units[241-243]