USE OF STERILE COMPARED WITH TAP WATER IN GASTROINTESTINAL ENDOSCOPICPROCEDURES

Background: Because of the concern for infection risk, use of sterile water has been recommended in the water bottle for endoscopic equipmen t, although studies evaluating prevalence of contamination of the wate r bottle with clinical outcomes have not been performed. Methods: Over a 12-week period in three endoscopy rooms at a university leaching ho spital, the water bottles were filled on a weekly schedule with either sterile (one room) or tap water. The water bottles were sterilized on a weekly basis with an automated endoscope washer. At the end of each week, an aliquot of the remaining water was transferred to a sterile container, and quantitative cultures for aerobic and facultative anaer obic bacteria were performed by use of a 0.01 ml calibrated loop accor ding to standard protocols. Cultures were performed in a blinded fashi on without knowledge of the water source. Follow-up was performed on a ll patients within 2 weeks of the procedure to determine any potential infectious complications. Results: During the study period, 437 proce dures were performed (203 endoscopy, 68 colonoscopy, 38 sigmoidoscopy, 128 endoscopic retrograde cholangiopancreatography). Of a total of 36 cultures (12 sterile), the results of nine (25%) were positive, inclu ding three bottles where sterile water was used. Bacterial isolates in cluded five Flavobacterium sp., four Acinetobacter sp., two Pseudomona s sp., and one Stenotrophomonas maltophilia. Colony counts ranged from 900 to more than 10,000 per ml. On follow-up no patient had developme nt of a clinical infection from any of these organisms. Conclusions: B acterial growth in the water bottle was infrequent, consisted predomin antly of nonpathogenic organisms, and was not associated with clinical complications. Our pilot study suggests that the use of lap water as compared with sterile water may be practical, as well as provide cost savings.