Recommendations and guidelines for endoscope reprocessing: Current position statement of digestive endoscopic society of Taiwan

Reprocessing of gastrointestinal (GI) endoscopes and accessories is an essential part of patient safety and quality control in GI endoscopy centers. However, current endoscopic reprocessing guidelines or procedures are not adequate to ensure patient-safe endoscopy. Approximately 5.4 % of the clinically used duodenoscopes remain contaminated with high-concern microorganisms. Thus, the Digestive Endoscopy Society of Taiwan (DEST) sets standards for the reprocessing of GI endoscopes and accessories in endoscopy centers. DEST organized a task force working group using the guideline-revision process. These guidelines contain principles and instructions of step-by-step for endoscope reprocessing. The updated guidelines were established after a thorough review of the existing global and local guidelines, systematic reviews, and health technology assessments of clinical effectiveness. This guideline aims to provide detailed recommendations for endoscope reprocessing to ensure adequate quality control in endoscopy centers.

Alcohol flush does not aid in endoscope channel drying but may serve as an adjunctive microbiocidal measure: A new take on an old assumption

BACKGROUND

Alcohol is perceived to aid flexible endoscope channel drying, however we previously showed alcohol increased the time required to dry some channels with forced air versus water alone. Yet, alcohol may prevent microorganism outgrowth during storage. Drying endoscope channels has been shown to prevent outgrowth, but it is unknown if incomplete drying (<10 µL remaining) provides similar protection.

METHODS

Endoscope channel test articles were used to determine the efficacy of 70%-30% alcohol flush for prevention of Pseudomonas aeruginosa outgrowth and drying efficiency. For non-alcohol flushed channels, the impact of forced air drying on outgrowth of P. aeruginosa was determined.

RESULTS

Alcohol flush (70%-30%) prevented outgrowth with little to no recovery of P. aeruginosa during ambient storage. 70% alcohol increased channel drying time by 1.5 or 3-fold compared to 50% alcohol or water, respectively. Forced air drying of non-alcohol flushed channels greatly reduced the initial contamination level and prevented outgrowth. Incomplete drying of contaminated channels was akin to no application of forced air. Applying forced air for more time than necessary to remove residual liquid did not completely eliminate the low level recovery of P. aeruginosa.

CONCLUSIONS

Flushing with reduced concentrations of alcohol may provide a strategy to prevent microbial outgrowth while reducing drying time.

How effective are the alcohol flush and drying cycles of automated endoscope reprocessors? Stripped endoscope model

BACKGROUND

Effective drying of the internal channels of endoscopes is essential to prevent the growth of water-borne pathogens and to assure adequate sterilization with vaporized hydrogen peroxide or ethylene oxide. The aim of this study was to evaluate the dryness of endoscopes after a routine disinfection process in an automated endoscope reprocessor.

METHODS

Stripped endoscopes (SE) that allow for visual inspection of the inside channels were reprocessed per protocol in a large urban medical center, with a 3-minute or 10-minute air flush following reprocessing. SE was hung and observed for any water within the channels after reprocessing and after a week of ambient storage. Ready-for-use endoscopes were also randomly spot-checked for moisture visually and with moisture detection paper.

RESULTS

All SE were grossly wet after HLD with a 3-minute air flush, despite alcohol flush and drying cycle. The 10-minute air flush was effective at drying the biopsy/suction channel, but not the air/water channels. Hanging had limited effect, being most effective in the biopsy/suction channels. Of the 77 ready-for-use respiratory and gastrointestinal endoscopes assessed, 37 (48.1%) showed evidence of retained moisture.

CONCLUSIONS

Air flush cycles commonly used in the final steps of automated endoscope reprocessing may not adequately dry endoscope channels, particularly the narrower diameter air/water channels. An extended 10-minute air flush appears effective at drying the larger biopsy/suction channel, but has limited effect on the air/water channels.

Microbiological surveillance post-reprocessing of flexible endoscopes used in digestive endoscopy: a national study

INTRODUCTION

Microbiological surveillance of endoscopes is a safety measure for verifying the quality of reprocessing procedures and identifying contaminated devices, but duodenoscope-related outbreaks are still reported.

AIM

To assess the effectiveness of duodenoscope reprocessing procedures in Italy.

METHODS

Between December 2019 and April 2020, data obtained from microbiological surveillance post-reprocessing in 15 Italian endoscopy units were collected. Sampling was carried out after reprocessing or during storage in a cabinet. In keeping with international guidelines and the Italian position paper, the micro-organisms were classified as high-concern organisms (HCOs) and low-concern organisms (LCOs).

FINDINGS

In total, 144 samples were collected from 51 duodenoscopes. Of these, 36.81% were contaminated: 22.92% were contaminated with HCOs and 13.89% were contaminated with LCOs [2.08% with an LCO load of 11-100 colony-forming units (CFU)/device and 0.69% with an LCO load of >100 CFU/device]. The contamination rate was 27.5% in samples collected after reprocessing, 40% in samples collected during storage in a cabinet that was compliant with EN 16442:2015 (C-I), and 100% in samples collected during storage in a cabinet that was not compliant with EN 16442:2015 (NC-I). The respective HCO rates were 15.00%, 27.27% and 66.67%. Correlation between LCO contamination and storage time was demonstrated (Spearman's rho=0.3701; P=0.0026). The Olympus duodenoscope TJFQ180V demonstrated the lowest rate of contamination (29.82%), although the contamination rate was 100% for duodenoscopes stored in an NC-I cabinet.

CONCLUSION

Microbiological surveillance, along with strict adherence to reprocessing protocols, may help to detect endoscope contamination at an early stage, and reduce the risk of duodenoscope-associated infections.

Efficacy of flexible endoscope drying using novel endoscope test articles that allow direct visualization of the internal channel systems

BACKGROUND

Thorough drying of flexible endoscope channels has been identified as an essential reprocessing step. Yet, instructions are not specific on how to dry endoscopes. There is lack of data supporting efficacy of current drying practices, due to limitations in determining channel dryness.

METHODS

Novel endoscope test articles were used to evaluate the effectiveness of alcohol flush and hanging in an ambient endoscope storage cabinet. Prepared test articles were hung in a storage cabinet for 5 days and visually inspected for residual liquid. The procedure for preoperative inspection of endoscopic systems was performed to determine the procedure's efficacy for removing residual liquid. Then, testing was performed to assess the impact of pressure, residual liquid type and route of air application on time to dry using compressed air.

RESULTS

Alcohol flush followed by hanging in an ambient storage cabinet was not effective for drying endoscope channels, and residual liquid was not completely removed after performing the steps of the preoperative inspection of endoscopic channels. The factors impacting effective compressed air drying were channel dependent. For some channels, alcohol increased the time to dry.

CONCLUSIONS

Endoscope drying is complex; borescope evaluation does not ensure a dry device.

Microbiological surveillance of endoscopes and implications for current reprocessing procedures adopted by an Italian teaching hospital

BACKGROUND

Hospital acquired infections have been associated with the contamination of flexible endoscopes caused by a failure of the reprocessing procedure. Microbiological surveillance of endoscope reprocessing is valuable for assessing contamination by pathogens. The aim of this study is to evaluate microbiological contamination of endoscopes after reprocessing, and the involvement of reprocessing procedures adopted in endoscopy units of an Italian teaching-hospital.

METHODS

The study was carried out, on several dates in 2014, in 11 endoscopic operation units equipped with 100 endoscopes (18 bronchoscopes, 41 gastroduodenoscopes, 29 colonoscopes, 12 laryngoscopes) and 9 Automated Endoscope Reprocessors. Presence/absence of common pathogens and indicator micro-organisms (including multi-drug resistant bacteria) and Total Microbiological Count (TMC) were obtained from the biopsy channels of endoscopes after reprocessing, from final rinse water of automated endoscope reprocessors and from tap water applying standard microbiological culture methods. Following the European Guidelines for quality assurance in reprocessing, the post-reprocessing criteria were "absence of indicator micro-organisms and absence of TMC in samples obtained from endoscopes' channels".

RESULTS

A total of 180 samples were collected (143 endoscopes, 25 Automated Endoscope Reprocessors and 12 water supply). Compliance to the European Guidelines was achieved for 112 out of the 180 (62.2%) samples analyzed. Presence of indicator micro-organisms (mainly Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa and other Gram-negative non-fermenting bacteria) was found in 51 out of 143 endoscopes (35.7%). Multi-drug resistant bacteria were also found. Presence of pathogen micro-organisms was statistically associated with the increase of TMC level, but not with time after reprocessing.

CONCLUSION

The study provides information about the microbiological quality of endoscope reprocessing procedures adopted by different endoscopic operation units. The high prevalence of contaminated endoscopes provides evidence of the need to improve the quality of reprocessing.

Novel Algorithms for Reprocessing, Drying and Storing Endoscopes

After outbreaks of duodenoscope-transmitted infection with multidrug-resistant organisms, it has become clear that institutions must optimize their endoscope reprocessing programs. Standard endoscope reprocessing practices may not represent the ideal approach for preventing transmission of infection related to endoscopy. We discuss multiple approaches to enhance and optimize reprocessing, drying, and storage of standard duodenoscopes. The optimal enhanced duodenoscope reprocessing modality remains to be determined. Acknowledging the challenges and limitations in effectively reprocessing duodenoscopes, the FDA issued a safety communiqué recommending transitioning to either single use disposable duodenoscopes or duodenoscopes with innovative designs that allow more effective reprocessing.

Methods for Endoscope Reprocessing

Over the past 2 decades, in hospital centers worldwide, there have been numerous outbreaks of multidrug-resistant organisms that have since been attributed to endoscopic transmission of the infections between patients, primarily from duodenoscopes. These outbreaks have focused the attention of endoscope manufacturers, professional societies, and regulatory agencies on improving the reprocessing of these devices. The key steps in this process are point-of-use precleaning, leak testing, manual cleaning, high-level disinfection, and finally drying and storage. The promise of these initial efforts suggest that the aim of minimizing and ultimately eliminating events of endoscope-/duodenoscope-associated transmission of infectious organisms between patients can be achieved.

SpyGlass application for duodenoscope working channel inspection: Impact on the microbiological surveillance

BACKGROUND

Patient-ready duodenoscopes were designed with an assumed contamination rate of less than 0.4%; however, it has been reported that 5.4% of clinically used duodenoscopes remain contaminated with viable high-concern organisms despite following the manufacturer’s instructions. Visual inspection of working channels has been proposed as a quality control measure for endoscope reprocessing. There are few studies related to this issue.

AIM

To investigate the types, severity rate, and locations of abnormal visual inspection findings inside patient-ready duodenoscopes and their microbiological significance.

METHODS

Visual inspections of channels were performed in 19 patient-ready duodenoscopes using the SpyGlass visualization system in two endoscopy units of tertiary care teaching hospitals (Tri-Service General Hospital and National Taiwan University Hospital) in Taiwan. Inspections were recorded and reviewed to evaluate the presence of channel scratches, buckling, stains, debris, and fluids. These findings were used to analyze the relevance of microbiological surveillance.

RESULTS

Seventy-two abnormal visual inspection findings in the 19 duodenoscopes were found, including scratches (n = 10, 52.6%), buckling (n = 15, 78.9%), stains (n = 14, 73.7%), debris (n = 14, 73.7%), and fluids (n = 6, 31.6%). Duodenoscopes > 12 mo old had a significantly higher number of abnormal visual inspection findings than those ≤ 12 mo old (46 findings vs 26 findings, P < 0.001). Multivariable regression analyses demonstrated that the bending section had a significantly higher risk of being scratched, buckled, and stained, and accumulating debris than the insertion tube. Debris and fluids showed a significant positive correlation with microbiological contamination (P < 0.05). There was no significant positive Spearman’s correlation coefficient between negative bacterial cultures and debris, between that and fluids, and the concomitance of debris and fluids. This result demonstrated that the presence of fluid and debris was associated with positive cultures, but not negative cultures. Further multivariate analysis demonstrated that fluids, but not debris, is an independent factor for bacterial culture positivity.

CONCLUSION

In patient-ready duodenoscopes, scratches, buckling, stains, debris, and fluids inside the working channel are common, which increase the microbiological contamination susceptibility. The SpyGlass visualization system may be recommended to identify suboptimal reprocessing.

Multidisciplinary and Multisociety Practice Guideline on Reprocessing Flexible Gastrointestinal Endoscopes and Endoscopic Accessories

The area of endoscopic application has been continuously expanded since its introduction in the last century and the frequency of its use also increased stiffly in the last decades. Because gastrointestinal endoscopy is naturally exposed to diseased internal organs and contact with pathogenic materials, endoscopy mediated infection or disease transmission becomes a major concern in this field. Gastrointestinal endoscopy is not for single use and the proper reprocessing process is a critical factor for safe and reliable endoscopy procedures. What needed in these circumstances is a practical guideline for reprocessing the endoscope and its accessories which is feasible in the real clinical field to guarantee acceptable prevention of pathogen transmission. This guideline contains principles and instructions of the reprocessing procedure according to the step by step. And it newly includes general information and updated knowledge about endoscopy-mediated infection and disinfection. Multiple societies and working groups participated to revise; Korean Association for the Study of the Liver, the Korean Society of Infectious Diseases, Korean College of Helicobacter and Upper Gastrointestinal Research, the Korean Society of Gastroenterology, Korean Society of Gastrointestinal Cancer, Korean Association for the Study of Intestinal Diseases, Korean Pancreatobiliary Association, the Korean Society of Gastrointestinal Endoscopy Nurses and Associates and Korean Society of Gastrointestinal Endoscopy. Through this cooperation, we enhanced communication and established a better concordance. We still need more researches in this field and fill up the unproven area. And our guidelines will be renewed accordingly.

Procedures in endoscope reprocessing and monitoring: an Italian survey

BACKGROUND

The high diffusion of endoscopes worldwide and the need for effective reprocessing methods requested the development of guidelines and implementation of surveillance procedures at local level.

STUDY DESIGN

In order to collect data on everyday's practice and adherence to available guidelines, endoscopy units from different public institutions were surveyed using a dedicated questionnaire.

METHODS

Between July and November 2015 a survey was carried in 12 main hospitals from 10 different Italian regions, involving 22 endoscopy units. The state of the art of national and international guidelines was investigated to compare the protocols adopted at local level.

RESULTS

In all the surveyed hospitals, the reprocessing activity is based on pre-established protocols in adherence with principal guidelines. Enzymatic detergents, which are recommended by the international guidelines, are used in 55.6% of units and peracetic acid is currently the most widely used chemical disinfectant. Discrepancies were observed in the application of periodic quality controls.

CONCLUSION

Updated guidelines are generally applied in reprocessing practice. Quality controls may represent a critical issue to improve effectiveness and surveillance. The whole of acquired data can promote a positive trend towards the application of best practices.

The validity of adenosine triphosphate measurement in detecting endoscope contamination

BACKGROUND

Endoscopic procedures are vital to gastrointestinal disease diagnosis and management, but risk infection transmission. In Australia, endoscopes undergo monthly-to-quarterly microbiological testing, to prevent patient infection. Endoscopes are used more frequently, meaning contamination may not be detected by this surveillance before infection transmission occurs.

AIM

To evaluate the use of adenosine triphosphate (ATP) measurement, alongside standard microbiological cultures, in detecting endoscope contamination before high-level disinfection. Using these results, we also aimed to confirm the efficacy of manual cleaning in reducing levels of ATP and cfu/mL.

METHODS

Seventeen in-clinical-use gastroscopes and 24 in-clinical-use colonoscopes from the Liverpool Hospital Endoscopy unit were sampled across three separate cleaning stages before high-level disinfection. Colony counts and ATP measurements were then performed on these samples.

FINDINGS

The correlation between the cfu/mL and RLU of samples collected from colonoscopes was 0.497 (95% confidence interval: 0.28-0.66; P < 0.0001). The correlation between cfu/mL and RLU for samples collected from gastroscopes was 0.377 (0.08-0.61; P = 0.0138). RLU and cfu/mL values were shown to fall significantly (P < 0.005) following precleaning and manual cleaning.

CONCLUSION

There was a significant correlation between ATP and cfu/mL measured from samples collected before high-level disinfection. Precleaning and manual cleaning were shown to reduce ATP and microbiological load significantly. ATP measurement can be performed within minutes with little training and produces results that are easy to interpret. These findings warrant further research on the utility of ATP measurement as a screening tool for detecting endoscope contamination after high-level disinfection.

Reusable endoscopic water bottles: is daily renewal really necessary?

Most guidelines recommend replacing endoscopic water bottles at least daily with newly sterilized or high-level disinfected water bottles. All these recommendations, however, are mainly based on expert opinions and outbreak reports. We tested the water quality from water bottles used in a gastrointestinal endoscopy unit where water bottles were used up to five days. The results show that the reuse of water bottles for more than one day is inadequate. The expert opinion in favour of changing water bottles daily rather than after five days is a sensible and safer option.

Korean Society of Gastrointestinal Endoscopy Guidelines for Endoscope Reprocessing

The Korean Society of Gastrointestinal Endoscopy (KSGE) issued guidelines for endoscope reprocessing for the first time in 1995, and the version of the guidelines was updated in August 2009, August 2012, and March 2015. Guidelines for endoscope reprocessing should be revised continuously, because new disinfectants and devices are developed and introduced. The current official version of the KSGE guidelines for endoscope reprocessing is explained herein to assist the reader in understanding the KSGE requirements for cleaning and disinfecting endoscopes.

Current Issues in Duodenoscope-Associated Infections: Now Is the Time to Take Action

A duodenoscope has a very complex structure that contains many small parts which make reprocessing more challenging. The difficulty in cleaning duodenoscopes contributes to a higher risk of infection than that of conventional gastrointestinal endoscopes. However, a duodenoscope shares similar disinfection process with other gastrointestinal endoscopes. Recent outbreaks of carbapenem-resistant Enterobacteriaceae (CRE) infections associated with duodenoscopes used for endoscopic retrograde cholangiopancreatography procedures have raised many concerns worldwide. Duodenoscope-associated infections involving CRE or other multidrug-resistant bacteria pose a great threat to patients undergoing procedures using duodenoscopes and should be dealt with a great concern. Updated guidelines regarding cleaning and disinfection of duodenoscope needs to be developed urgently to prevent transmission of infection and ensure patient safety. Meanwhile, healthcare staff should pay special attention to thorough cleaning and disinfection of duodenoscopes.

Persistent contamination on colonoscopes and gastroscopes detected by biologic cultures and rapid indicators despite reprocessing performed in accordance with guidelines

BACKGROUND

Pathogens have been transmitted via flexible endoscopes that were reportedly reprocessed in accordance with guidelines.

METHODS

Researchers observed reprocessing activities to ensure guideline compliance in a large gastrointestinal endoscopy unit. Contamination was assessed immediately after bedside cleaning, manual cleaning, high-level disinfection, and overnight storage via visual inspection, aerobic cultures, and tests for adenosine triphosphate (ATP), protein, carbohydrate, and hemoglobin.

RESULTS

All colonoscopes and gastroscopes were reprocessed in accordance with guidelines during the study. Researchers collected and tested samples during 60 encounters with 15 endoscopes. Viable microbes were recovered from bedside-cleaned (92%), manually cleaned (46%), high-level disinfected (64%), and stored (9%) endoscopes. Rapid indicator tests detected contamination (protein, carbohydrate, hemoglobin, or ATP) above benchmarks on bedside-cleaned (100%), manually cleaned (92%), high-level disinfected (73%), and stored (82%) endoscopes. Visible residue was never observed on endoscopes, but it was often seen on materials used to sample endoscopes. Seven endoscopes underwent additional reprocessing in response to positive rapid indicators. Control endoscope channels were free of biologic residue and viable microbes.

CONCLUSION

Despite reprocessing in accordance with US guidelines, viable microbes and biologic debris persisted on clinically used gastrointestinal endoscopes, suggesting current reprocessing guidelines are not sufficient to ensure successful decontamination.

Correlation between the growth of bacterial biofilm in flexible endoscopes and endoscope reprocessing methods

BACKGROUND

The purpose of this article was to investigate bacterial biofilm formed on endoscopes and to explore the possible correlation between endoscope reprocessing procedures and bacterial biofilm growth on endoscope channels.

METHODS

Sixty-six endoscope suction and biopsy channels and 13 water and air channels were collected from 66 hospitals throughout China. Scanning electron microscopy was used to observe biofilm growth on the internal surface of these channels. Questionnaires were mailed to 66 endoscopy centers to investigate reprocessing procedures for endoscopes.

RESULTS

Obvious biofilm growth was detected on 36 suction and biopsy channels (36/66, 54.6%) and 10 water and air channels (10/13, 76.9%). The percentage of manual cleaning in group B (n = 36, without detection of biofilms) was 92.3% (33/36), whereas it was 50.0% (15/30) in group A (n = 30, with detection of biofilms). Follow-up of group A (n = 30) showed that no biofilm was detected, whereas biofilm was detected in group B. The difference was statistically significant (P = .001). The proportion of detergent reuse in group B was 92.3% (33/36), and it was 61.5% in group A (18/30) (P = .005). The proportion of alcohol-air drying in group B was 38.9% (14/36), and it was 76.7% (23/30) in group A (P = .002).

CONCLUSION

The formation of endoscopic biofilm during clinical practice may be related to reuse of detergent, manual cleaning, and incomplete drying.

Comparison on the Efficacy of Disinfectants Used in Automated Endoscope Reprocessors: PHMB-DBAC versus Orthophthalaldehyde

BACKGROUND/AIMS

Since endoscopes are reusable apparatus classified as semicritical item, thorough reprocessing to achieve high-level disinfection is of utmost importance to prevent spread of infection. To improve disinfection efficacy and safety, disinfectants and endoscope reprocessors are continuously evolving. This study aimed to compare the efficacy of the combination of polyhexamethylenebiguanide hydrochloride-alkyldimethylbenzylammonium chloride (PHMB-DBAC) and orthophthalaldehyde (OPA) used respectively in ultrasonographic cleaning incorporated automated endoscope reprocessors: COOLENDO (APEX Korea) or OER-A (Olympus Optical).

METHODS

A total of 86 flexible upper endoscopes were randomly reprocessed with either COOLENDO/PHMB-DBAC or OER-A/OPA. Culture samplings were done at two sites (endoscope tip and working channel) which were later incubated on blood agar plate. Bacterial colonies were counted and identified.

RESULTS

The culture-positive rate at the endoscope tip and working channel was 0% and 2.33% for COOLENDO/PHMB-DBAC and 4.65% and 0% for OER-A/OPA. Staphylococcus hominis was cultured from one endoscope reprocessed with COOLENDO/PHMB-DBAC and Pseudomonas putida was isolated from two endoscopes reprocessed with OER-A/OPA.

CONCLUSIONS

The reprocessing efficacy of COOLENDO/PHMB-DBAC was non-inferior to that of OER-A/OPA (p=0.032; confidence interval, -0.042 to 0.042). During the study period, significant side effect of PHMB-DBAC was not observed.