Surveillance culture monitoring of double-balloon enteroscopy reprocessing with high-level disinfection

Advances in balloon endoscopes

In September 2003, a double-balloon endoscope (DBE) composed of balloons attached to a scope and an overtube was released in Japan prior to becoming available in other parts of the world. The DBE was developed by Dr. Yamamoto (1), and 5 different types of scopes with different uses have already been marketed. In April 2007, a single-balloon small intestinal endoscope was released with a balloon attached only to the overtube as a subsequent model. This article presents a detailed account of the development of these scopes up to the present time.

High pressure air jet in the endoscopic preparation room: risk of noise exposure on occupational health

After high-level disinfection of gastrointestinal endoscopes, they are hung to dry in order to prevent residual water droplets impact on patient health. To allow for quick drying and clinical reuse, some endoscopic units use a high pressure air jet (HPAJ) to remove the water droplets on the endoscopes. The purpose of this study was to evaluate the excessive noise exposure with the use of HPAJ in endoscopic preparation room and to investigate the risk to occupational health. Noise assessment was taken during 7 automatic endoscopic reprocessors (AERs) and combined with/without HPAJ use over an 8-hour time-weighted average (TWA). Analytical procedures of the NIOSH and the ISO for noise-induced hearing loss were estimated to develop analytic models. The peak of the noise spectrum of combined HPAJ and 7 AERs was significantly higher than that of the 7 AERs alone (108.3 ± 1.36 versus 69.3 ± 3.93 dBA, P < 0.0001). The risk of hearing loss (HL > 2.5 dB) was 2.15% at 90 dBA, 11.6% at 95 dBA, and 51.3% at 100 dBA. The odds ratio was 49.1 (95% CI: 11.9 to 203.6). The noise generated by the HPAJ to work over TWA seriously affected the occupational health and safety of those working in an endoscopic preparation room.

Endoscopic biopsy as quality assurance for endoscopic services

Gastroendoscopy (GS) procedures are not only performed by gastroenterologists (GE) but also by hepatologists (HT) in many countries. Endoscopic biopsy (EBx) remains the gold standard for the investigation and documentation of esophago-gastro-duodenal pathology. EBx is subjectively performed by an endoscopist, and the level of skill and experience of the endoscopist may affect the quality of the endoscopic service. Reasons for this discrepancy included lack of experience practitioners to order EBx when required of GS issues between in GE and HT limit access. Ideally, services should be safe and of high quality. This study assessed the EBx/GS ratio as the endoscopic quality assurance as an index of GS services. This was a cohort study of endoscopists at Kaohsiung Chang Gung Memorial Hospital, a teaching hospital in southern Taiwan. There were 34,570 episodes of EBx in 199,877 GS procedures. The 25 endoscopists were divided into GE (n = 13) and HT (n = 12) groups, and correlation coefficients were calculated over a 14.5-year duration of intervention. The Trimmean of EBx/GS was 19.29% in 14.5 years (34570/199877 with Trimmean 0.2 percentile ratio correlations), and the Pearson correlation coefficient was 0.90229. There were significantly more EBx procedures in the GE group than in the HT group at 1 and 5 years (21.5% vs. 15.1% and 20.9% vs. 17.3%, respectively, P<0.00001). Junior GE attempted significantly more EBx than both the senior GE (24.06% vs. 20.41%, P<0.0001), and junior HT (24.06% vs. 13.2%, P<0.0001). In conclusion, quality assurance for gastrointestinal endoscopy involves numerous aspects of unit management and patient safety. Quality measures used with the EBx/GS ratio may be one of the best ways to ensure the quality of endoscopic procedures in a teaching hospital.

Surveillance cultures of samples obtained from biopsy channels and automated endoscope reprocessors after high-level disinfection of gastrointestinal endoscopes

Background

The instrument channels of gastrointestinal (GI) endoscopes may be heavily contaminated with bacteria even after high-level disinfection (HLD). The British Society of Gastroenterology guidelines emphasize the benefits of manually brushing endoscope channels and using automated endoscope reprocessors (AERs) for disinfecting endoscopes. In this study, we aimed to assess the effectiveness of decontamination using reprocessors after HLD by comparing the cultured samples obtained from biopsy channels (BCs) of GI endoscopes and the internal surfaces of AERs.

Methods

We conducted a 5-year prospective study. Every month random consecutive sampling was carried out after a complete reprocessing cycle; 420 rinse and swabs samples were collected from BCs and internal surface of AERs, respectively. Of the 420 rinse samples collected from the BC of the GI endoscopes, 300 were obtained from the BCs of gastroscopes and 120 from BCs of colonoscopes. Samples were collected by flushing the BCs with sterile distilled water, and swabbing the residual water from the AERs after reprocessing. These samples were cultured to detect the presence of aerobic and anaerobic bacteria and mycobacteria.

Results

The number of culture-positive samples obtained from BCs (13.6%, 57/420) was significantly higher than that obtained from AERs (1.7%, 7/420). In addition, the number of culture-positive samples obtained from the BCs of gastroscopes (10.7%, 32/300) and colonoscopes (20.8%, 25/120) were significantly higher than that obtained from AER reprocess to gastroscopes (2.0%, 6/300) and AER reprocess to colonoscopes (0.8%, 1/120).

Conclusions

Culturing rinse samples obtained from BCs provides a better indication of the effectiveness of the decontamination of GI endoscopes after HLD than culturing the swab samples obtained from the inner surfaces of AERs as the swab samples only indicate whether the AERs are free from microbial contamination or not.

Swab culture monitoring of automated endoscope reprocessors after high-level disinfection

AIM: To conduct a bacterial culture study for monitoring decontamination of automated endoscope reprocessors (AERs) after high-level disinfection (HLD).

METHODS: From February 2006 to January 2011, authors conducted randomized consecutive sampling each month for 7 AERs. Authors collected a total of 420 swab cultures, including 300 cultures from 5 gastroscope AERs, and 120 cultures from 2 colonoscope AERs. Swab cultures were obtained from the residual water from the AERs after a full reprocessing cycle. Samples were cultured to test for aerobic bacteria, anaerobic bacteria, and mycobacterium tuberculosis.

RESULTS: The positive culture rate of the AERs was 2.0% (6/300) for gastroscope AERs and 0.8% (1/120) for colonoscope AERs. All the positive cultures, including 6 from gastroscope and 1 from colonoscope AERs, showed monofloral colonization. Of the gastroscope AER samples, 50% (3/6) were colonized by aerobic bacterial and 50% (3/6) by fungal contaminations.

CONCLUSION: A full reprocessing cycle of an AER with HLD is adequate for disinfection of the machine. Swab culture is a useful method for monitoring AER decontamination after each reprocessing cycle. Fungal contamination of AERs after reprocessing should also be kept in mind.