Gastroscopy-associated transmission of extended-spectrum beta-lactamase-producing Pseudomonas aeruginosa

Efficacy of spray flushing in the reprocessing of flexible endoscopes: A randomized controlled trial

BACKGROUND

Commonly used cleaning brushes in the reprocessing of flexible endoscopes often cause damage within the working channels.

AIM

To develop a spray flushing system to achieving effective cleaning of the working channels while minimizing damage.

METHODS

This prospective study included 60 used endoscopes and 60 Teflon tubes randomly divided into a control group (n = 30) and an experimental group (n = 30). The material of Teflon tubes was the same as that of the endoscope working channel. Endoscopes in the control group were manually cleaned using traditional cleaning brushes, while those in the experimental group were cleaned using the newly developed spray flushing system. ATP levels, cleanliness, and microbiological testing of the working channels were measured. Additionally, Teflon tubes in the control group underwent 500 passes with a cleaning brush, while those in the experimental group were subjected to the spray flushing system, and channel damage was evaluated.

RESULTS

The ATP levels (RLU) in the two groups were 32.5 (13-66) and 26 (16-40), respectively (P > 0.05). Cleanliness scores were 1.5 (1-2) and 1 (1-2), respectively (P > 0.05). Debris was found in 73.3% of the control group, which was significantly higher than 46.7% in the experimental group (P < 0.05). Microbiological tests for both groups yielded negative results. Teflon tube damage in the control group was rated at 4 (4-5.25), which was significantly higher than in the experimental group 4 (3-4) (P < 0.01).

CONCLUSION

The spray flushing system demonstrated superior efficacy in removing debris and resulted in less damage to the endoscope working channels compared with traditional cleaning brushes.

Endoscope channel drying, storage, and conditions after reprocessing: How safe are they in clinical practice?

INTRODUCTION AND AIMS

Adequate drying and proper storage of flexible endoscopes are essential for maintaining quality in their reprocessing. The aim of the present study was to evaluate the drying stages, storage, and channel conditions of endoscopes through borescope inspection.

MATERIAL AND METHODS

The personnel responsible for endoscope reprocessing were interviewed. Storage conditions at 10 endoscopy facilities were inspected and an internal examination of the channels and ports of the stored equipment was carried out, utilizing a borescope. A total of 74 stored endoscope channels were evaluated.

RESULTS

Only 10% of the facilities inspected utilized transport cases for storage and only 10% had rooms exclusively used for storage. Sixty percent of the facilities did not perform any shelf-life control. All the channels evaluated were scratched and fluids were present on 69% of them.

CONCLUSIONS

Endoscope reprocessing can be improved through the implementation of drying and storage control and validation tools, as well as the use of borescopes and periodic clinical audits.

Evaluation of a novel disposable endoscope for retroflexed endoscopic rubber band ligation of internal hemorrhoids: a randomized pilot study

PURPOSE

Retroflexed endoscopic rubber band ligation (ERBL) for treating Grade II and III internal hemorrhoids using disposable endoscopes has not been previously assessed. We therefore compared the safety and effectiveness of ERBL for internal hemorrhoids using novel disposable endoscopes versus traditional reusable endoscopes.

METHODS

This prospective randomized controlled trial involved 42 patients who underwent ERBL for Grade II and III internal hemorrhoids using either a disposable endoscope (n = 21) or a reusable endoscope (n = 21). Safety was assessed by the incidence of equipment failure, device-related adverse events, and in-procedure stability of vital signs. Effectiveness was assessed by the postoperative therapeutic effect, feasibility of retroflexed ERBL, and incidence of complications.

RESULTS

In terms of safety, no life-threatening events, equipment failure, or device-related adverse effects occurred during the procedures in either group. The rate of diastolic blood pressure stability was significantly different between the two groups (P = .049), but the rates of systolic blood pressure and heart rate stability were similar. In terms of effectiveness, the therapeutic effects on postoperative Day 30 were similar in both groups. Image clarity and endoscopic flexibility in the disposable endoscope group were mildly inferior to those in the reusable endoscope group, but without statistical significance. Matching between the endoscope and ligating device was 100% in both groups. The incidence of complications on postoperative Days 1 and 10 was not significantly different between the two groups.

CONCLUSION

Compared with reusable endoscopes, disposable endoscopes are equally safe, feasible, and reliable in ERBL for internal hemorrhoids.

The Evolution of Spinal Endoscopy: Design and Image Analysis of a Single-Use Digital Endoscope Versus Traditional Optic Endoscope

Spinal endoscopy has evolved significantly since its inception, offering minimally invasive solutions for various spinal pathologies. This study introduces a promising innovation in spinal endoscopy-a single-use digital endoscope designed to overcome the drawbacks of traditional optic endoscopes. Traditional endoscopes, despite their utility, present challenges such as fragility, complex disinfection processes, weight issues, and susceptibility to mechanical malfunctions. The digital endoscope, with its disposable nature, lighter weight, and improved image quality, aims to enhance surgical procedures and patient safety. The digital endoscope system comprises a 30-degree 1000 × 1000 pixel resolution camera sensor with a 4.3 mm working channel, and LED light sources replacing optical fibers. The all-in-one touch screen tablet serves as the host computer, providing portability and simplified operation. Image comparisons between the digital and optic endoscopes revealed advantages in the form of increased field of view, lesser distortion, greater close-range resolution, and enhanced luminance. The single-use digital endoscope demonstrates great potential for revolutionizing spine endoscopic surgeries, offering convenience, safety, and superior imaging capabilities compared to traditional optic endoscopes.

Effect of a disposable endoscope precleaning kit in the cleaning procedure of gastrointestinal endoscope: A multi-center observational study

BACKGROUND

Precleaning is a key step in endoscopic reprocessing.

AIM

To develop an effective and economic endoscope cleaning method by using a disposable endoscope bedside precleaning kit.

METHODS

Altogether, 228 used gastrointestinal endoscopes were selected from five high-volume endoscopy units and precleaned by a traditional precleaning bucket (group T) or a disposable endoscope bedside precleaning kit (group D). Each group was further subdivided based on the replacement frequency of the cleaning solution, which was replaced every time in subgroups T1 and D1 and every several times in subgroups Ts and Ds. The adenosine triphosphate (ATP) level and residual proteins were measured three times: Before and after precleaning and after manual cleaning.

RESULTS

After precleaning, the precleaning kit significantly reduced the ATP levels (P = 0.034) and has a more stable ATP clearance rate than the traditional precleaning bucket. The precleaning kit also saved a quarter of the cost of enzymatic detergent used during the precleaning process. After manual cleaning, the ATP levels were also significantly lower in the precleaning kit group than in the traditional precleaning bucket group (P < 0.05). Meanwhile, the number of uses of the cleaning solution (up to four times) has no significant impact on the cleaning effect (P > 0.05).

CONCLUSION

Considering its economic cost and cleaning effect, the use of a disposable endoscope bedside precleaning kit can be an optimal option in the precleaning stage with the cleaning solution being replaced several times in the manual cleaning stage.

New Hydrogels Nanocomposites Based on Chitosan, 2-Formylphenylboronic Acid, and ZnO Nanoparticles as Promising Disinfectants for Duodenoscopes Reprocessing

New hydrogels nanocomposites, based on iminoboronate hydrogels and ZnO nanoparticles (ZnO-NPs), were obtained and characterised in order to develop a new class of disinfectants able to fight the nosocomial infections produced by duodenoscopes investigation procedures. The formation of the imine linkages between chitosan and the aldehyde was demonstrated using NMR and FTIR spectroscopy, while the supramolecular architecture of the developed systems was evaluated via wide-angle X-ray diffraction and polarised optical microscopy. The morphological characterisation of the systems via scanning electron microscopy revealed the highly porous structure of the materials, in which no ZnO agglomeration could be observed, indicating the very fine and homogenous encapsulation of the nanoparticles into the hydrogels. The newly synthetised hydrogels nanocomposites was proven to have synergistic antimicrobial properties, being very efficient as disinfectants against reference strains as: Enterococcus faecalis, Klebsiella pneumoniae, and Candida albicans.

Evaluation of cold atmospheric plasma for the decontamination of flexible endoscopes

BACKGROUND

Despite adherence to standard protocols, residues including live microorganisms may remain on the various surfaces of reprocessed flexible endoscopes. Prions are infectious proteins notoriously difficult to eliminate.

AIM

We tested the potential of cold atmospheric plasma (CAP) for the decontamination of flexible endoscope various surfaces, measuring total proteins and prion-residual infectivity as an indicator of efficacy.

METHODS

New PTFE endoscope channels and metal test surfaces spiked with test soil or prion-infected tissues were treated using different CAP-generating prototypes. Surfaces were then examined for the presence of residues using very sensitive fluorescence epi-microscopy. Prion residual infectivity was determined using the wire implant animal model and a new, more sensitive cell infectivity assay.

FINDINGS

A CAP jet applied perpendicularly at close range on flat test surfaces removed soil within 3 minutes but left microscopic residues and failed to eliminate prion infectivity according to the wire implant animal assay. The longitudinal gas flow from CAP prototypes developed for the treatment of long channels led to the displacement and sedimentation of residual soil towards the distal end, when applied alone. Observations of the plasma inside glass tubes showed temporal and spatial heterogeneity within a limited range. After standard enzymatic manual pre-wash, "CAP-activated" gas effluents prevented prion transmission from treated endoscope channels according to our prion infectivity cell assay.

CONCLUSION

CAP shows promising results as a final step for surgical surfaces decontamination. Optimising CAP delivery could further enhance CAP efficacy, offering a safe, chemical-free alternative for the reprocessing of all luminal flexible endoscope surfaces.

Criteria for the Use, Processing, and Disposal of Flexible Endoscope Cleaning Brushes

Objectives: To ensure effectiveness in the endoscope channel cleaning process, using functional brushes that are in good condition is necessary. This study sought to identify the criteria for acquiring, using, and disposing of cleaning brushes at endoscopy facilities in Brazil. We further sought to evaluate the conditions of the cleaning brushes in use in the facilities. Methods: This cross-sectional study was conducted between July 2021 and January 2022. Personnel responsible for processing endoscopes were interviewed regarding the use, processing, and disposal of flexible endoscope cleaning brushes. In addition, the brushes used to clean the equipment were inspected. Results: All participants interviewed reported the practice of brushing endoscope channels. Of them, 60% noted the use of disposable brushes, with 40% using reusable brushes. None of the facilities interviewed reported discarding disposable brushes after use. The protocols for disposal of brushes included disposing due to bristle wear (70%), disposal at the end of the day (20%), and an absence of disposal protocols (10%). In addition, 30% of facilities did not clean the bristles before reintroducing them into the channel/lumen, and no facility had an established routine for cleaning brushes between uses. Inspection of brushes revealed that only 20% of facilities had new brushes with no signs of wear or damage. Conclusion: The use of inappropriate brushes/sponges for cleaning endoscope channels and the lack of criteria for the reuse and disposal of brushes increases the risk of cross-contamination, internal damage to channels, and biofilm formation.

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.

Evaluation of the Application Effect of a New Anti-reflux Water Injection Tube Device in the Prevention of the Contamination of Endoscopy Water Injection Bottles

BACKGROUND

Water delivery tube reflux during gastrointestinal endoscopy examination is widespread and it is the leading cause of water injection bottle pollution.

AIM

To evaluate the application effect of a new anti-reflux water injection tube device in preventing the contamination of endoscopy water injection bottles.

METHODS

A total of 520 cases received gastrointestinal endoscopy examination were included. Patients were randomly divided into the experimental and control group. The experimental group used the anti-reflux injection tube device to assist with water injection, and the control group used the ordinary delivery tube. After every five cases of gastrointestinal endoscopy, water from the injection bottles was collected. Visual inspection, crystalline violet staining, microbial culture, and microbial species analysis were performed to analyze the contamination state of the water samples.

RESULTS

The contamination rate in the experimental group was 5.66%, significantly lower than 76.47% in the control group. Crystalline violet staining confirmed that microorganisms existed in contaminated water samples. Microbiological culture results showed that the experimental group's undetectable rate of bacteria and fungi was 100%, significantly higher than that of the control group (19.61% for bacteria and 25.49% for fungi). The mean values of the total bacterial and fungal colonies of the control samples were 9.80 × 10⁶ cfu/ml and 9.18 × 10⁶ cfu/ml, respectively. The microbial species in the contaminated samples of the control group were Pseudomonas aeruginosa, Escherichia coli, and Proteus mirabilis.

CONCLUSION

The anti-reflux water injection tube device can effectively prevent the contamination of the endoscopy water injection bottles caused by the reflux of the ordinary water supply tube.

Life Cycle Assessment of Reusable and Disposable Cystoscopes: A Path to Greener Urological Procedures

BACKGROUND

The environmental impact of reusable and disposable devices is unclear; reuse is expected to reduce the carbon footprint, but the environmental impact of reprocessing of reusable devices is increasingly being questioned.

OBJECTIVE

The aim was to provide the first rigorous life cycle assessment of reusable and disposable flexible cystoscopes.

DESIGN, SETTING, AND PARTICIPANTS

We performed a life cycle assessment of reusable flexible cystoscopes and the aS4C single-use cystoscope (aScope; Ambu, Ballerup, Denmark). For the aScope, the complete lifespan of the scope was evaluated, including raw material extraction, material formulation, component production, product assembly, distribution, transportation after use, and final disposal. For reusable cystoscopes, we limited our analysis to their reprocessing, using a model consisting of standard high-level disinfection with peracetic acid. The environmental impact was evaluated by an independent third-party consulting company APESA (Technopole Hélioparc, Pau, France) dedicated to such risk assessments.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The environmental footprint of both cystoscopes was assessed using five environmental impact categories, namely, climate change, mineral resource depletion, ecotoxicity, acidification, and eutrophication. To perform the life cycle assessment, Simapro v9.3.3 software was used and the Ecoinvent v3.5 database was employed as the primary life cycle inventory database. A Monte Carlo analysis was used to account for the inherent uncertainty in life cycle inventory data and the variability in material and energy consumption for each type of flexible cystoscope.

RESULTS AND LIMITATIONS

By only comparing the disinfection reprocessing of reusable cystoscopes with the complete lifespan of the single-use cystoscope, the use of the aScope would allow a reduction of at least 33% in the climate change category, 50% in the mineral resources' depletion category, 51% in the ecotoxicity category, 71% in the acidification category, and 49% in the eutrophication category. Our results cannot be generalized to all health care facilities as we studied only one type of reprocessing method and one disposable flexible cystoscope.

CONCLUSIONS

Disinfection reprocessing of reusable cystoscopes was found to have a significantly larger environmental footprint and impact than the whole lifespan of the single-use cystoscope aScope.

PATIENT SUMMARY

Using a cradle-to-grave life cycle analysis, we showed that the environmental footprint of a flexible cystoscopy procedure can be reduced by using a disposable cystoscope instead of a reusable cystoscope.

Cost and Environmental Impact of Disposable Flexible Cystoscopes Compared to Reusable Devices

Objectives: To quantify the environmental impact and costs associated with flexible cystoscopy procedures from an institutional perspective, with particular attention for the comparison between disposable and reusable cystoscopes. Materials and Methods: This is a single-center retrospective study, including all flexible cystoscopies performed between 2020 and 2021 using reusable or single-use devices. The Ambu aS4C single-use cystoscope (Ballerup, Denmark) gradually replaced the reusable device in our center, with exclusive use from October 2021. Reprocessing costs for reusable cystoscopes were evaluated using a micro-costing approach. The environmental impact of reusable and disposable cystoscopes was assessed by the amount of waste and water consumed for each procedure. Results: A total of 1578 flexible cystoscopies using reusable cystoscopes were performed in 2020, and 550 cystoscopies were performed using the Ambu aS4C cystoscope from October 2021 to February 2022. The cost of flexible cystoscopy with a reusable and a disposable endoscope was €196 and €192, respectively. The amount of waste generated by reprocessing reusable and disposable cystoscopes was 800 and 200 g per procedure, respectively. Water consumption for sterilization of the reusable cystoscope was 60 L per procedure, whereas no water consumption was required with the Ambu aS4C cystoscope. A 100% Ambu aS4C cystoscope use would reduce waste generation and water consumption by 946.8 kg and 94.68 m3 per year. Conclusion: In this study, implementing a strategy of using 100% disposable cystoscopes was associated with similar costs and reduced waste generation and water consumption compared to reusable devices. Future studies are needed to compare the carbon footprint of these devices, through a comprehensive and rigorous life cycle assessment from manufacturing to recycling.

Disposable versus reusable gastroscopes: a prospective randomized noninferiority trial

BACKGROUND AND AIMS

Disposable gastroscopes have recently been developed to eliminate the risk of infection transmission from contaminated reusable gastroscopes. We compared the performance of disposable and reusable gastroscopes in patients undergoing gastroscopy.

METHODS

Patients requiring gastroscopy were randomized to either the disposable or reusable digital gastroscope group. The primary endpoint was the success rate of photographing customary anatomic sites, with a noninferiority margin of -8%. Secondary endpoints were technical performance factors such as gastroscope imaging quality, maneuverability, gastroscopy completion rate, device failure/defect rate, operating time, and safety. Data were analyzed using the Newcombe-Wilson score method and Fisher exact 2-tailed t test.

RESULTS

Of 110 patients, 55 were treated using disposable gastroscopes and 55 using reusable gastroscopes. The success rate for capturing images of customary anatomic sites was 100% in both groups. The average imaging quality score was significantly lower (37.02 ± 3.09 vs 39.47 ± 1.92, P < .001) and the operating time significantly longer (P < .001) in the disposable gastroscope group. No significant differences in maneuverability, gastroscopy completion rate, device failure/defect rate, operating time, or safety were found between the 2 groups.

CONCLUSIONS

Given the overall safety profile and similar technical performance, disposable gastroscopes represent an alternative to reusable gastroscopes for routine examination, bedside first aid, and some certain circumstances.

Gastrointestinal endoscope contamination rates - elevators are not only to blame: a systematic review and meta-analysis

Background and study aims  Duodenoscopes that are contaminated due to inadequate reprocessing are well-documented. However, studies have demonstrated poor reprocessing of other kinds of endoscopes as well, including echoendoscopes, gastroscopes, and colonoscopes. We estimated the contamination rate beyond the elevator of gastrointestinal endoscopes based on available data. Methods  We searched PubMed and Embase from January 1, 2010 to October 10, 2020, for studies investigating contamination rates of reprocessed gastrointestinal endoscopes. A random-effects model was used to calculate the contamination rate of patient-ready gastrointestinal endoscopes. Subgroup analyses were conducted to investigate differences among endoscope types, countries, and colony-forming unit (CFU) thresholds. Results  Twenty studies fulfilled the inclusion criteria, including 1,059 positive cultures from 7,903 samples. The total contamination rate was 19.98 % ± 0.024 (95 % confidence interval [Cl]: 15.29 %-24.68 %; I ²  = 98.6 %). The contamination rates of colonoscope and gastroscope channels were 31.95 % ± 0.084 and 28.22 % ± 0.076, respectively. Duodenoscope channels showed a contamination rate of 14.41 % ± 0.029. The contamination rates among studies conducted in North America and Europe were 6.01 % ± 0.011 and 18.16% ± 0.053 %, respectively. The contamination rate among studies using a CFU threshold > 20 showed contamination of 30.36 % ± 0.094, whereas studies using a CFU threshold < 20 showed a contamination rate of 11 % ± 0.026. Conclusions  On average, 19.98 % of reprocessed gastrointestinal endoscopes may be contaminated when used in patients and varies between different geographies. These findings highlight that the elevator mechanism is not the only obstacle when reprocessing reusable endoscopes; therefore, guidelines should recommend more surveillance of the endoscope channels as well.

Contaminated flexible endoscopes: Review of impact of channel sampling methods on culture results and recommendations for root-cause analysis

Recently, infection transmission risk associated with contaminated, patient-ready flexible endoscopes has attracted attention. Outbreaks of multidrug-resistant organisms resulting in infection and/or colonization have been particularly concerning. Recent CDC and FDA recommendations focus on reducing "exogenous" infection transmission and specifically recommend that endoscopy sites have quality systems in place for endoscope reprocessing. Another key recommendation is the culture of patient-ready endoscopes to detect contamination with organisms of concern. Remaining gaps in the guidelines include ensuring that optimal endoscope-channel sample methods are used and ensuring effective root-cause analysis and remediation when contamination is detected. In this review, we summarize the critical aspects of endoscope sample collection and present a practical approach to root-cause analysis and remedial action plans.

Gastrointestinal Endoscopy-Associated Infections: Update on an Emerging Issue

Over 17.7 million gastrointestinal (GI) endoscopic procedures are performed annually, contributing to 68% of all endoscopic procedures in the United States. Usually, endoscopic procedures are low risk, but adverse events may occur, including cardiopulmonary complications, bleeding, perforation, pancreatitis, cholangitis, and infection. Infections after the GI endoscopies most commonly result from the patient's endogenous gut flora. Although many studies have reported infection after GI endoscopic procedures, a true estimate of the incidence rate of post-endoscopy infection is lacking. In addition, the infection profile and causative organisms have evolved over time. In recent times, multi-drug-resistant microorganisms have emerged as a cause of outbreaks of endoscope-associated infections (EAI). In addition, lapses in endoscope reprocessing have been reported, with some but not all outbreaks in recent times. This systematic review summarizes the demographical, clinical, and management data of EAI events reported in the literature. A total of 117 articles were included in the systematic review, with the majority reported from North America and Western Europe. The composite infection rate was calculated to be 0.2% following GI endoscopic procedures, 0.8% following ERCP, 0.123% following non-ERCP upper GI endoscopic procedures, and 0.073% following lower GI endoscopic procedures. Pseudomonas aeruginosa was the most common culprit organism, followed by other Enterobacteriaceae groups of organisms and Gram-positive cocci. We have also elaborated different prevention methods such as antimicrobial prophylaxis, adequate sterilization methods for reprocessing endoscopes, periodic surveillance, and current evidence supporting their utilization. Finally, we discuss disposable endoscopes, which could be an alternative to reprocessing to minimize the chances of EAIs with their effects on the environmental and financial situation.

Risk evaluation of duodenoscope-associated infections in the Netherlands calls for a heightened awareness of device-related infections: a systematic review

BACKGROUND

The risk of exogenous infections from endoscopic procedures is often cited as almost negligible (1 infection in 1.8 million procedures); however, this risk is based on older literature and does not seem to match the number of infectious outbreaks due to contaminated duodenoscopes reported after endoscopic retrograde cholangiopancreatography (ERCP). Using Dutch data, we aimed to estimate the minimum risk of duodenoscope-associated infection (DAI) and colonization (DAC) in patients undergoing ERCP.

METHODS

A systematic literature search identified all DAI outbreaks in the Netherlands reported between 2008 and 2019. Included cases were confirmed by molecular matching of patient and duodenoscope cultures. Risk ratios were calculated based on the total number of ERCPs performed during the study period.

RESULTS

Three outbreaks were reported and published between 2008 and 2018, including 21 confirmed DAI cases and 52 confirmed DAC cases. The estimated number of ERCPs performed during the same period was 181 209-227 006. The calculated minimum estimated DAI risk was approximately 0.01 % and the minimum estimated DAC risk was 0.023 %-0.029 %.

CONCLUSIONS

The estimated risk of DAI in Dutch ERCP practice was at least 180 times higher than previously published risk estimates. The actual risk is likely to be (much) higher due to underreporting of infections caused by multidrug-resistant organisms and sensitive bacteria. Greater awareness by healthcare personnel involved in endoscopy and endoscope cleaning is required, as well as innovative technical solutions to contain and ultimately eliminate DAIs.

Medical Device Sterilization and Reprocessing in the Era of Multidrug-Resistant (MDR) Bacteria: Issues and Regulatory Concepts

The emergence of multidrug-resistant (MDR) bacteria threatens humans in various health sectors, including medical devices. Since formal classifications for medical device sterilization and disinfection were established in the 1970's, microbial adaptation under adverse environmental conditions has evolved rapidly. MDR microbial biofilms that adhere to medical devices and recurrently infect patients pose a significant threat in hospitals. Therefore, it is essential to mitigate the risk associated with MDR outbreaks by establishing novel recommendations for medical device sterilization, in a world of MDR. MDR pathogens typically thrive on devices with flexible accessories, which are easily contaminated with biofilms due to previous patient use and faulty sterilization or reprocessing procedures. To prevent danger to immunocompromised individuals, there is a need to regulate the classification of reprocessed medical device sterilization. This article aims to assess the risks of improper sterilization of medical devices in the era of MDR when sterilization procedures for critical medical devices are not followed to standard. Further, we discuss key regulatory recommendations for consistent sterilization of critical medical devices in contrast to the risks of disinfection reusable medical devices.

Storage of gastrointestinal endoscopes: when is the safe time for re-use?

ABSTRACT Objectives: to identify the safe storage time for the use of flexible gastrointestinal endoscopes after high-level disinfection, as well as the defining criteria for this time. Methods: an integrative literature review was carried out in the Virtual Health Library, PubMed, Scopus, and Web of Science, considering original articles published since 2000. Results: eleven articles were selected, whose storage times ranged from 1 to 56 days, with a predominance of one to seven days (73%). Several criteria were used to define this time, predominantly the premise of efficient processing (100%), use of alcohol flush (64%), use of drying cabinets (18%), among others. Conclusions: the criteria for determining the storage time did not show a consensus for clinical practice. Expanding the discussion of this theme with the definition of the minimum necessary conditions is of fundamental importance for the reduction of risks and safety of the procedure and the patient.

A narrative review on current duodenoscope reprocessing techniques and novel developments

Duodenoscopy-associated infections occur worldwide despite strict adherence to reprocessing standards. The exact scope of the problem remains unknown because a standardized sampling protocol and uniform sampling techniques are lacking. The currently available multi-society protocol for microbial culturing by the Centers for Disease Control and Prevention, the United States Food and Drug Administration (FDA) and the American Society for Microbiology, published in 2018 is too laborious for broad clinical implementation. A more practical sampling protocol would result in increased accessibility and widespread implementation. This will aid to reduce the prevalence of duodenoscope contamination. To reduce the risk of duodenoscopy-associated pathogen transmission the FDA advised four supplemental reprocessing measures. These measures include double high-level disinfection, microbiological culturing and quarantine, ethylene oxide gas sterilization and liquid chemical sterilization. When the supplemental measures were advised in 2015 data evaluating their efficacy were sparse. Over the past five years data regarding the supplemental measures have become available that place the efficacy of the supplemental measures into context. As expected the advised supplemental measures have resulted in increased costs and reprocessing time. Unfortunately, it has also become clear that the efficacy of the supplemental measures falls short and that duodenoscope contamination remains a problem. There is a lot of research into new reprocessing methods and technical applications trying to solve the problem of duodenoscope contamination. Several promising developments such as single-use duodenoscopes, electrolyzed acidic water, and vaporized hydrogen peroxide plasma are already applied in a clinical setting.

Outbreak of Pseudomonas aeruginosa Infections from a Contaminated Gastroscope Detected by Whole Genome Sequencing Surveillance

BACKGROUND

Traditional methods of outbreak investigations utilize reactive whole genome sequencing (WGS) to confirm or refute the outbreak. We have implemented WGS surveillance and a machine learning (ML) algorithm for the electronic health record (EHR) to retrospectively detect previously unidentified outbreaks and to determine the responsible transmission routes.

METHODS

We performed WGS surveillance to identify and characterize clusters of genetically-related Pseudomonas aeruginosa infections during a 24-month period. ML of the EHR was used to identify potential transmission routes. A manual review of the EHR was performed by an infection preventionist to determine the most likely route and results were compared to the ML algorithm.

RESULTS

We identified a cluster of 6 genetically related P. aeruginosa cases that occurred during a 7-month period. The ML algorithm identified gastroscopy as a potential transmission route for 4 of the 6 patients. Manual EHR review confirmed gastroscopy as the most likely route for 5 patients. This transmission route was confirmed by identification of a genetically-related P. aeruginosa incidentally cultured from a gastroscope used on 4of the 5 patients. Three infections, 2 of which were blood stream infections, could have been prevented if the ML algorithm had been running in real-time.

CONCLUSIONS

WGS surveillance combined with a ML algorithm of the EHR identified a previously undetected outbreak of gastroscope-associated P. aeruginosa infections. These results underscore the value of WGS surveillance and ML of the EHR for enhancing outbreak detection in hospitals and preventing serious infections.

The Effect of Brush Motion and Rinsing When Manually Cleaning Cannulated Medical Devices

Cleaning cannulated medical devices can be challenging for perioperative and sterile processing department personnel. We performed a laboratory experimental study to evaluate differences in cleaning effectiveness using either a back-and-forth or helical spinning brushing motion and the effect of rinsing the bristles at each reintroduction of the brush in the lumen. We also tested the lumen cleanliness after high-pressure water cleansing without brushing. We inspected the devices to determine whether visible soil remained, and we measured the amount of residual organic matter using adenosine triphosphate testing to determine cleaning method effectiveness. The results showed that rinsing the brush during cleaning decreased the amount of organic material that remained in the lumen. A helical spinning motion with brush rinsing at each reintroduction of the brush may be more effective than back-and-forth brushing with rinsing, but additional testing with a larger sample size is required to determine whether this result is replicable.

The polytetrafluoroethylene (PTFE) channel model of cyclic-buildup biofilm and traditional biofilm: The impact of friction, and detergent on cleaning and subsequent high-level disinfection

OBJECTIVE

To evaluate the efficacy of detergent and friction on removal of traditional biofilm and cyclic-buildup biofilm (CBB) from polytetrafluoroethylene (PTFE) channels and to evaluate the efficacy of glutaraldehyde to kill residual bacteria after cleaning.

METHODS

PTFE channels were exposed to artificial test soil containing 108 CFU/mL of Pseudomonas aeruginosa and Enterococcus faecalis, followed by full cleaning and high-level disinfection (HLD) for five repeated rounds to establish CBB. For traditional biofilm, the HLD step was omitted. Cleaning with enzymatic and alkaline detergents, bristle brush, and Pull Thru channel cleaner were compared to a water flush only. Carbohydrate, protein, viable count, adenosine triphosphate (ATP) levels were analyzed and atomic force microscopy (AFM) was performed.

RESULTS

In the absence of friction, cleaning of traditional biofilm and CBB was not effective compared to the positive control (Dunn-Bonferroni tests; P > .05) regardless of the detergent used. ATP, protein, and carbohydrate analyses were unable to detect traditional biofilm or CBB. The AFM analysis showed that fixation resulted in CBB being smoother and more compact than traditional biofilm.

CONCLUSION

Friction during the cleaning process was a critical parameter regardless of the detergent used for removal of either traditional biofilm or CBB. Glutaraldehyde effectively killed the remaining microorganisms regardless of the cleaning method used.

'Secondary biofilms' could cause failure of peracetic acid high-level disinfection of endoscopes

INTRODUCTION

The reduced susceptibility of biofilms to disinfectants presents a challenge to the successful reprocessing of medical equipment. This study examined the effect of residual biomass remaining after previous disinfection with peracetic acid (PAA) on the tolerance of subsequent mature Pseudomonas aeruginosa biofilms to PAA. The effect of enzymatic degradation of specific components of the extracellular polymeric substance (EPS) of P. aeruginosa biofilm on the effectiveness of PAA disinfection was also evaluated.

METHODS

The susceptibility of biofilm grown on the biomass of PAA-killed biofilm to PAA was compared with the PAA susceptibility of biofilm grown in wells of a 24-well plate by evaluating their viability using the plate count assay. The effect of PAA on biofilm biomass was measured using crystal violet quantification of total biofilm biomass, while its effect on the polysaccharide and protein components of biofilm EPS was quantified using the phenol-sulphuric acid assay or Bradford assay, respectively. A confocal microscope was used to visualize the distribution of living and dead cells in biofilms grown on residual biofilm biomass.

FINDINGS

The presence of residual biomass from previously disinfected biofilms significantly enhanced the tolerance of subsequent biofilms. A 96-h-old 'secondary biofilm' formed on disinfected biomass survived PAA concentrations of 4000 ppm, which exceeds the concentrations used in practice for high-level disinfection.

CONCLUSION

These observations indicate that, under certain circumstances, recolonization of residual EPS can cause failure of disinfection of medical equipment such as endoscopes, and emphasizes the importance of cleaning endoscopes prior to disinfection.

The Effectiveness of Drying on Residual Droplets, Microorganisms, and Biofilms in Gastrointestinal Endoscope Reprocessing: A Systematic Review

BACKGROUND

Despite endoscope reprocessing, residual droplets remain in gastrointestinal endoscope working channels. Inadequate drying of gastrointestinal endoscope working channels may promote microbial reproduction and biofilm formation, increasing the risk of infection in patients. This review was designed to provide the current status of gastrointestinal endoscope drying, emphasize the importance of gastrointestinal endoscope drying, and evaluate the effectiveness of different drying methods of gastrointestinal endoscope in reducing residual droplets and microbial growth risk.

METHODS

A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting checklist. The PubMed, Web of Science, Medline, EMBASE, EBSCO, CNKI, CQVIP, and Wanfang Data databases were searched from 2010 to 2020 to identify eligible articles focused on methods of gastrointestinal endoscope drying and the status of endoscope drying. The following key points were analyzed: type of intervention, amount of residual droplets, major microbial types, and effectiveness of biofilm intervention. JBI quality assessment tool was used to determine bias risk for inclusion in the article.

RESULTS

This review included twelve articles. Two of the articles reported lack of drying of gastrointestinal endoscopes while the other ten reported residual droplets, microbial growth, and biofilm formation after different methods of drying. Four articles reported 0 to 4.55 residual droplets; four articles reported that the main microbial types were cocci and bacilli, most commonly Staphylococcus, Escherichia coli, Bacillus maltophilia, and Pseudomonas aeruginosa; and two reported that drying could effectively reduce biofilm regeneration. The type of intervention is as follows: automatic endoscopy reprocessor (AER), manual compressed air drying, and the Dri-Scope Aid for automatic drying and drying cabinet.

CONCLUSIONS

While endoscope reprocessing may not always be effective, an automatic endoscope reprocessor plus the Dri-Scope Aid with automatic drying over 10 min or storage in a drying cabinet for 72 h may be preferred.

Challenges in achieving effective high-level disinfection in endoscope reprocessing

Endoscope reprocessing is often ineffective, and microbes frequently remain on endoscopes after the use of high-level disinfectants (HLDs). Several factors impact reprocessing effectiveness, including non-adherence to guidelines, use of damaged endoscopes, use of insoluble products during endoscopy, insufficient cleaning, contaminated rinse water, and inadequate drying before storage. Our team suspected that issues with HLD chemistries and monitoring could also contribute to reprocessing failures. We conducted a mixed-methods analysis of published literature, our interviews with frontline personnel, and evidence from our previous studies. The evidence showed that reusable HLDs commonly failed tests for minimum effective concentration (MEC) before their maximum usage periods. MEC tests also detected failures associated with single-use HLDs that did not fully deploy. These failures were due to product issues, process complexities, and personnel non-adherence with guidelines and manufacturer instructions. HLDs will likely continue to be used for the foreseeable future. More research is needed to assess real-world practice patterns related to the high-level disinfection step and MEC testing and to establish more realistic usage periods for reusable HLD chemistries. Manufacturers and researchers should evaluate the ability of technological solutions and engineered safeguards to overcome human error. Recognition of the need for quality improvement is growing, and infection preventionists should take action to build on this momentum and collaborate with manufacturers, endoscopists, and reprocessing personnel to improve the effectiveness of high-level disinfection.

Is Post-Reprocessing Microbiological Surveillance of Duodenoscopes Effective in Reducing the Potential Risk in Transmitting Pathogens?

Background: The use of a contaminated endoscope may lead to infections due to the transmission of potential pathogens from patient to patient. Methods: Post-reprocessing microbiological surveillance of four duodenoscopes was carried out over a three-year period in the Digestive Endoscopy Unit of an Italian hospital. Sampling of duodenoscopes was performed after the devices have been reprocessed. The initial phase of surveillance involved the contemporary evaluation of the four duodenoscopes; afterwards, microbiological surveillance proceeded at monthly intervals. Results: The initial phase of surveillance revealed that three duodenoscopes presented a high level of contamination with “high-concern” micro-organisms, some of which were multi-drug-resistant. The highest values of contamination regarded the species P. aeruginosa (2500 CFU/duodenoscope), K. pneumoniae (2580 CFU/duodenoscope), and A. baumannii (2600 CFU/duodenoscope). Since the cultures were repeatedly positive on three successive occasions, the contaminated devices were sent to the manufacturer for evaluation. Audits were carried out with the personnel responsible for reprocessing, which was aimed to optimize the procedures used, and subsequently, only one case of non-conformity was found. Conclusions: Our study highlighted both the potential risk of transmitting pathogens through the use of duodenoscopes and the importance of implementing a well-structured system of microbiological surveillance and training programs, in order to reduce the risk of spreading retrograde cholangiopancreatography (ERCP)-associated infections.

[Medical Dispute Related to Gastrointestinal Endoscopy Complications: Prevention and Management]

Because gastrointestinal (GI) endoscopy examinations are being performed increasingly frequently, the rate of detection of cancer and of precancerous lesions has increased. Moreover, development of more advanced endoscopic technologies has expanded the indications for, and thus frequency of, therapeutic endoscopic procedures. However, the incidence of complications associated with diagnostic or therapeutic GI endoscopy has also increased. The complications associated with GI endoscopy can be ameliorated by endoscopic or conservative treatment, but caution is needed as some of the more serious complications, such as perforation, can lead to death. In this chapter, we review the possible complications of GI endoscopy and discuss methods for their prevention and treatment.

Endoscope reprocessing: Comparison of drying effectiveness and microbial levels with an automated drying and storage cabinet with forced filtered air and a standard storage cabinet

BACKGROUND

Automated drying may help prevent endoscopically transmitted infections. We aimed to assess the efficacy of an automated drying and storage cabinet compared to a standard storage cabinet in achieving endoscope dryness postreprocessing and in reducing the risk of microbial growth.

METHODS

Drying times of bronchoscopes, colonoscopes, and duodenoscopes using 2 drying platforms (an automated drying and storage cabinet vs a standard storage cabinet) were measured using cobalt chloride paper. Drying assessments occurred at: 30 minutes, 1 hour, 2 hours, 3 hours, and 24 hours. A simple linear regression analysis compared rates of microbial growth after inoculation with Pseudomonas aeruginosa following high-level disinfection at: 0, 3 hours, 12 hours, 24 hours, and 48 hours.

RESULTS

Using the automated drying and storage cabinet, internal channels were dry at 1 hour and external surfaces at 3 hours in all endoscopes. With the standard storage cabinet, there was residual internal fluid at 24 hours, whereas external surfaces were dry at 24 hours. For bronchoscopes, colonoscopes, and duodenoscopes, the standard cabinet allowed for an average rate of colony forming unit growth of 8.1 × 10⁶ per hour, 8.3 × 10⁶ per hour, and 7.0 × 10⁷ per hour, respectively; the automated cabinet resulted in colony forming unit growth at an average rate of -28.4 per hour (P = .02), -38.5 per hour (P = .01), and -200.2 per hour (P = .02), respectively.

CONCLUSIONS

An automated cabinet is advantageous for rapid drying of endoscope surfaces and in reducing the risk of microbial growth postreprocessing.

A Systematic Review of Disposable Sheath Use During Flexible Endoscopy

Flexible endoscopes are exposed to blood, mucus, and other secretions during procedures. Single-use sheaths are designed to prevent contact between contaminants and reusable endoscope components. This systematic review examined findings from 22 studies that assessed endoscopic sheath use during urologic, gastrointestinal, or respiratory procedures. The evidence showed that sheaths were durable and yielded faster endoscope turnover times because their reusable components did not require high-level disinfection or sterilization. After a brief learning period, health care providers successfully assembled and maneuvered sheathed endoscopes. Patients generally did not experience greater discomfort during procedures in which sheaths were used. Microbial cultures of sheathed endoscopes were negative or similar to unsheathed endoscopes. More research is needed to evaluate the potential effect of disposable sheaths on infection risks. The evidence suggests that sheaths are a viable option for reliably providing a barrier between endoscopes and patients without affecting the quality of endoscopic procedures.

On-site comparison of an enzymatic detergent and a non-enzymatic detergent-disinfectant for routine manual cleaning of flexible endoscopes

Background and study aims  Flexible endoscopes are potential vectors of pathogen transmission to patients that are subjected to cleaning and high-level disinfection after each procedure. Efficient manual cleaning is a prerequisite for effective high-level disinfection. The goal of this study was to demonstrate the impact of the cleaning chemistry in the outcome of the manual cleaning of endoscopes. Materials and methods  Twelve endoscopes were included in this study: four colonoscopes, four gastroscopes, two duodenoscopes and two bronchoscopes. This study was designed with two phases; in each of them, the manual cleaning procedure remained identical, but a different detergent was used: a non-enzymatic detergent-disinfectant (NEDD) and an enzymatic detergent (ED). Biopsy and suction channels of endoscopes were sampled using 10 mL of physiological saline at two points: before and after manual cleaning, and adenosine triphosphate (ATP) was measured on each sample. In total, 208 procedures were analyzed for the NEDD phase and 253 for the ED phase. Results  For each endoscope type, cleaning endoscopes with ED resulted in larger median decrease in ATP than with NEDD: respectively 99.43 % and 95.95 % for bronchoscopes ( P  = 0.0007), 99.28 % and 96.93 % for colonoscopes ( P  < 0.0001) and 98.36 % and 95.36 % for gastroscopes ( P  < 0.0001). In addition, acceptability rates of endoscopes based on defined post-manual cleaning ATP thresholds (200, 150, 100 or 50 relative light units) for all endoscope types were significantly higher with ED compared to NEDD. Conclusions  With all other parameters of manual cleaning remaining unchanged, the enzymatic chemistry of ED provided more consistent and improved cleaning of endoscopes compared to NEDD. Therefore, choice of the detergent for endoscope cleaning has an impact on the outcome of this process.

An update on gastrointestinal endoscopy-associated infections and their contributing factors

INTRODUCTION

During clinical use, gastrointestinal endoscopes are grossly contaminated with patient's native flora. These endoscopes undergo reprocessing to prevent infectious transmission upon future use. Endoscopy-associated infections and outbreaks have been reported, with a recent focus on the transmission of multi-drug resistant organisms. This review aims to provide an update on endoscopy-associated infections, and the factors contributing to their occurrence.

METHODS

PubMed, ScienceDirect, and CINAHL were searched for articles describing gastrointestinal endoscopy-associated infections and outbreaks published from 2008 to 2018. Factors contributing to their occurrence, and the outcomes of each outbreak were also examined.

RESULTS

This review found 18 articles, 16 of which described duodenoscope-associated infections, and the remaining two described colonoscope- and gastroscope-associated infection respectively. Outbreaks were reported from the United States, France, China, Germany, the Netherlands and the United Kingdom. The causative organisms reported were Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli and Salmonella enteritidis.

CONCLUSIONS

A number of factors, including lapses in reprocessing, biofilm formation, endoscope design issues and endoscope damage, contribute to gastrointestinal endoscopy associated infection. Methods of improving endoscope reprocessing, screening for contamination and evaluating endoscope damage may be vital to preventing future infections and outbreaks.

Scoping the scope: endoscopic evaluation of endoscope working channels with a new high-resolution inspection endoscope (with video)

BACKGROUND AND AIMS

Outbreaks of transmission of infection related to endoscopy despite reported adherence to reprocessing guidelines warrant scrutiny of all potential contributing factors. Recent reports from ambulatory surgery centers indicated widespread significant occult damage within endoscope working channels, raising concerns regarding the potential detrimental impact of this damage on the adequacy of endoscope reprocessing.

METHODS

We inspected working channels of all 68 endoscopes at our academic institution using a novel flexible inspection endoscope. Inspections were recorded and videos reviewed by 3 investigators to evaluate and rate channel damage and/or debris. Working channel rinsates were obtained from all endoscopes, and adenosine triphosphate (ATP) bioluminescence was measured.

RESULTS

Overall endoscope working channel damage was rated as minimal and/or mild and was consistent with expected wear and tear (median 1.59 on our 5-point scale). Our predominant findings included superficial scratches (98.5%) and scratches with adherent peel (76.5%). No channel perforations, stains, or burns were detected. The extent of damage was not predicted by endoscope age. Minor punctate debris was common, and a few small drops of fluid were noted in 42.6% of endoscopes after reprocessing and drying. The presence of residual fluid predicted higher ATP bioluminescence values. The presence of visualized working channel damage or debris was not associated with elevated ATP bioluminescence values.

CONCLUSION

The flexible inspection endoscope enables high-resolution imaging of endoscope working channels and offers endoscopy units an additional modality for endoscope surveillance, potentially complementing bacterial cultures and ATP values. Our study, conducted in a busy academic endoscopy unit, indicated predominately mild damage to endoscope working channels, which did not correlate with elevated ATP values.

Pediatric Endoscopic Procedure Complications

PURPOSE OF REVIEW

This review summarizes the current body of research, define high-risk patients and endoscopic processes, and outline evidence-based countermeasures aimed at minimizing the incidence of complications during endoscopy in children.

RECENT FINDINGS

Significant complications of endoscopy requiring emergency department or inpatient admission in otherwise healthy children are unusual, but more common with therapeutic procedures; risk from procedures increases incrementally with preoperative coexisting conditions. Duodenal hematoma is predominantly a pediatric endoscopic complication and is more likely in hematology-oncology patients. Air embolism is a well-defined endoscopic retrograde cholangiopancreatography (ERCP) complication in adults and is likely to increase in children with increased performance of pediatric ERCP. Increased physician expertise is the most often proposed countermeasure, especially in the context of endoscopy complications in the higher-risk patient and procedure. Endoscopy in children remains a very safe group of procedures, although a more detailed understanding of risk factors and ideal training and practice organization is lacking.

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.

Residual moisture and waterborne pathogens inside flexible endoscopes: Evidence from a multisite study of endoscope drying effectiveness

BACKGROUND

Endoscopy-associated infection transmission is frequently linked to inadequate reprocessing. Residual organic material and moisture may foster biofilm development inside endoscopes. This study evaluated the effectiveness of endoscope drying and storage methods and assessed associations between retained moisture and contamination.

METHODS

Endoscope reprocessing, drying, and storage practices were assessed at 3 hospitals. Researchers performed visual examinations and tests to detect fluid and contamination on patient-ready endoscopes.

RESULTS

Fluid was detected in 22 of 45 (49%) endoscopes. Prevalence of moisture varied significantly by site (5%; 83%; 85%; P < .001). High adenosine triphosphate levels were found in 22% of endoscopes, and microbial growth was detected in 71% of endoscopes. Stenotrophomonas maltophilia, Citrobacter freundii, and Lecanicillium lecanii/Verticillium dahliae were found. Retained fluid was associated with significantly higher adenosine triphosphate levels (P < .01). Reprocessing and drying practices conformed with guidelines at 1 site and were substandard at 2 sites. Damaged endoscopes were in use at all sites.

CONCLUSIONS

Inadequate reprocessing and insufficient drying contributed to retained fluid and contamination found during this multisite study. More effective methods of endoscope reprocessing, drying, and maintenance are needed to prevent the retention of fluid, organic material, and bioburden that could cause patient illness or injury.

The effectiveness of sterilization for flexible ureteroscopes: A real-world study

BACKGROUND

There are no guidelines or quality benchmarks specific to ureteroscope reprocessing, and patient injuries and infections have been linked to ureteroscopes. This prospective study evaluated ureteroscope reprocessing effectiveness.

METHODS

Reprocessing practices at 2 institutions were assessed. Microbial cultures, biochemical tests, and visual inspections were conducted on sterilized ureteroscopes.

RESULTS

Researchers examined 16 ureteroscopes after manual cleaning and sterilization using hydrogen peroxide gas. Every ureteroscope had visible irregularities, such as discoloration, residual fluid, foamy white residue, scratches, or debris in channels. Tests detected contamination on 100% of ureteroscopes (microbial growth 13%, adenosine triphosphate 44%, hemoglobin 63%, and protein 100%). Contamination levels exceeded benchmarks for clean gastrointestinal endoscopes for hemoglobin (6%), adenosine triphosphate (6%), and protein (100%). A new, unused ureteroscope had hemoglobin and high protein levels after initial reprocessing, although no contamination was found before reprocessing.

CONCLUSIONS

Flexible ureteroscope reprocessing methods were insufficient and may have introduced contamination. The clinical implications of residual contamination and viable microbes found on sterilized ureteroscopes are unknown. Additional research is needed to evaluate the prevalence of suboptimal ureteroscope reprocessing, identify sources of contamination, and determine clinical implications of urinary tract exposure to reprocessing chemicals, organic residue, and bioburden. These findings reinforce the need for frequent audits of reprocessing practices and the routine use of cleaning verification tests and visual inspection as recommended in reprocessing guidelines.

Endoscope drying and its pitfalls

Inadequate drying of endoscope channels is a possible cause of replication and survival of remaining pathogens during storage. The presence during storage of potentially contaminated water in endoscope channels may promote bacterial proliferation and biofilm formation. An incomplete drying procedure or lack of drying and not storing in a vertical position are the most usual problems identified during drying and endoscope storage. Inadequate drying and storage procedures, together with inadequate cleaning and disinfection, are the most important sources of endoscope contamination and post-endoscopic infection. Flexible endoscopes may be dried in automated endoscope reprocessors (AERs), manually, or in drying/storage cabinets. Flushing of the endoscope channels with 70-90% ethyl or isopropyl alcohol followed by forced air drying is recommended by several guidelines. Current guidelines recommend that flexible endoscopes are stored in a vertical position in a closed, ventilated cupboard. Drying and storage cabinets have a drying system that circulates and forces the dry filtered air through the endoscope channels. Endoscope reprocessing guidelines are inconsistent with one another or give no exact recommendations about drying and storage of flexible endoscopes. There is no conclusive evidence on the length of time endoscopes can be safely stored before requiring re-disinfection and before they pose a contamination risk. To minimize the risk of disease transmission and nosocomial infection, modification and revision of guidelines are recommended as required to be consistent with one another.