Disposable Bronchoscope Model for Simulating Endoscopic Reprocessing and Surveillance Cultures

Gastrointestinal Endoscopy 30-day-associated Bacteremia: Non-outbreak Five-Year Review in an Inner-City, Tertiary-Care Hospital

INTRODUCTION

Gastrointestinal endoscopic procedures (GIEP's) are an essential part of patient care both diagnostically and therapeutically. Post-GIEP infections may be higher than previously reported and may not have been accurately captured in the past. The aim of this study was to determine the incidence and associated factors of bacteremia associated with GIEP's.

METHODS

This is retrospective study of GIEPs performed over a five-year period (2018-2022) at an academic medical center. Electronic health records (EHR) identified GIEPs and positive blood cultures within 30 days of procedure. Statistical analysis was performed using non-parametric testing to compare variables due to the small number of positive blood cultures.

RESULTS

EHR identified 18,986 GIEP's and 52 true and unique bacteremia out of 17,093 blood cultures during the five-year study period. The highest rate of positive blood culture of 2.84% (18/634) was associated with ERCP and the lowest 0.08% (7/9029) was associated with colonoscopy.

DISCUSSION

This study showed a reflection of the endemic rate of bacteremia post GIEP's. Although this study cannot differentiate endogenous infection versus contaminated (exogenous) endoscopes, an effort was made to eliminate other causes of bacteremia. ERCP procedures are disproportionately associated with higher incidence of bacteremia.

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.

The Cost of Flexible Bronchoscopes: A Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVE

Until 2009, only reusable bronchoscopes were marketed, but the introduction and widespread adoption of single-use flexible bronchoscopes (SFBs) as an emerging technology has since accelerated. Several studies have described the costs of reusable flexible bronchoscopes (RFBs) and SFBs. This meta-analysis aimed to compile the current published evidence to analyse the cost of different scenarios using RFBs and SFBs.

METHODS

All published literature describing the cost of RFBs or SFBs was identified by searching PubMed, Embase and Google Scholar, limited to those between 1 January, 2009 and 6 November, 2020. Included studies should report the total cost of RFBs. Continuous data were extracted for relevant outcomes and analysed using RStudio^® 4.0.3 as the standardised mean difference and standard error of the mean in a mixed-effects model. Risk of bias was assessed based on the reporting quality.

RESULTS

In the systematic literature review, 342 studies were initially identified, and 11 were included in the final analysis. The mean RFB procedure cost was $266 (standard error of the mean: 34), including capital investments, repairs and reprocessing costs of $91, $92 and $83, respectively. The mean SFB procedure cost was $289 (standard error of the mean: 10). The incremental cost was $23 (standard error of the mean: 33) and was not significant (p = 0.46). Because of the economy of scale, RFB is more likely to be cost minimising compared with SFB when performing 306 or 39 procedures per site or RFB, respectively.

CONCLUSIONS

In this study, we found no significant difference in the cost of use between RFBs and SFBs and a high risk of bias.

Borescope Examination and Microbial Culture Results of Endoscopes in a Tertiary Care Hospital Led to Changes in Storage Protocols to Improve Patient Safety

BACKGROUND

Flexible endoscopes are highly versatile and useful medical instruments, and their proper reprocessing is critical to patient health and safety. The value of routine visual inspections and surveillance of endoscopes in a tertiary care hospital was assessed by performing borescope examinations and microbial sampling on respiratory, gastro-intestinal (GI), and urological endoscopes.

METHODS

A total of 42 endoscopes were cultured, and 36 endoscopes were examined with a borescope. The flush-brush-flush method was used to culture the endoscopes. Microbiologic sampling water was vortexed prior to being suctioned through a membrane filter device. The membrane was plated on a blood agar plate and incubated at 37°C for 48 hours. A 1.9-meter borescope with a 1.6mm diameter was used to perform borescope examinations in an antegrade and retrograde approach.

RESULTS

Positive microbial cultures were seen in 28% of bronchoscopes, 22% of GI endoscopes, and 30% of urological endoscopes. Only Gram-positive colonies were identified in endoscopes that had microbial growth. Borescope examinations revealed multiple abnormalities and damage including channel shredding, filamentous debris, water retention, discoloration, dents, and red particles.

CONCLUSIONS

Borescope examination and microbial sampling should be used routinely to assure endoscopic safety. Borescope examination enabled us to visualize structural damage, foreign material, and moisture within endoscopes. The structural damages and the particles found in endoscopes resulted in timely repair and discontinuation of this type of distal end protectors in our facility.

Both microbiological surveillance and audit of procedures improve reprocessing of flexible bronchoscopes and patient safety

BACKGROUND

Microbiological surveillance of bronchoscopes and automatic endoscope reprocessors (AERs)/washer disinfectors as a quality control measure is controversial. Experts also are divided on the infection risks associated with bronchoscopic procedures.

OBJECTIVE

We evaluated the impact of routine microbiological surveillance and audits of cleaning/disinfection practices on contamination rates of reprocessed bronchoscopes.

DESIGN

Audits were conducted of reprocessing procedures and microbiological surveillance on all flexible bronchoscopes used from January 2007 to June 2020 at a teaching hospital in France. Contamination rates per year were calculated and analyzed using a Poisson regression model. The risk factors for microbiological contamination were analyzed using a multivariable logistical regression model.

RESULTS

In total, 478 microbiological tests were conducted on 91 different bronchoscopes and 57 on AERs. The rate of bronchoscope contamination significantly decreased between 2007 and 2020, varying from 30.2 to 0% (P < .0001). Multivariate analysis confirmed that retesting after a previous contaminated test was significantly associated with higher risk of bronchoscope contamination (OR, 2.58; P = .015). This finding was explained by the persistence of microorganisms in bronchoscopes despite repeated disinfections. However, the risk of persistent contamination was not associated with the age of the bronchoscope.

CONCLUSIONS

Our results confirm that bronchoscopes can remain contaminated despite repeated reprocessing. Routine microbial testing of bronchoscopes for quality assurance and audit of decontamination and disinfection procedures can improve the reprocessing of bronchoscopes and minimize the rate of persistent contamination.

Delftia acidovorans pseudo outbreak in portable reverse osmosis machines: Interventions to ensure safe and cost-effective hemodialysis

INTRODUCTION

Reverse osmosis (RO), a major advance in hemodialysis (HD) safety, effectively clears most water organisms. Delftia acidovorans is an environmental water-borne pathogen that is rarely reported to cause human infections. We report a pseudo outbreak caused by colonization of RO machines with D acidovorans with no reported human infections and interventions to improve HD safety.

METHODS

Repeated positive RO product water cultures triggered our hospital to initiate an investigation, RO machines were examined for mechanical integrity by biomedical engineers. Cultures of product water as well as RO parts were done. Testing for bacterial relatedness after identification was performed. An investigation was conducted in a systematic fashion to determine the cause and the extent of the problem.

RESULTS

Upon formal review of policies and procedures, there were minor deficiencies. Rectifying these deviations from policies did not stop the repeated positive water cultures. A 7-step investigation and correction was successfully conducted. City water testing with filtration and concentration methods was positive for D acidovorans. Major renovation of the HD unit with replacement of all RO machines and a 2-step water filtration resulted in elimination of the pseudo outbreak.

CONCLUSION

City water was the source of biofilm formation of D acidovorans in RO machines that was not possible to eradicate. Application of incoming water filters was an effective preventive strategy. Replacement of RO machines after 4 failed disinfection attempts is the most cost-effective strategy as well for persistent positive water cultures. The HD remains RO water culture negative 2 years after changes.