Endoscopy-related outbreaks in absence of obvious processing error represent the tip of an iceberg. The elevator channel and ethylene oxide sterilization were blame and fix in endoscope processing. Repeated use, time of procedure and time to processing are potential causes for biofilm formation within endoscopes. Once a biofilm is formed, it cannot be eradicated using high-level disinfection (HLD) or sterilization. Even though sterilization is reported to have more bacteial reduction than HLD, this does not apply to biofilm formation.
Time of the procedure and time to processing are hypothesized to be the most important risk factors for failure of endoscope processing. We reviewed all endoscopic procedure times with respect to type and indication of endoscopic procedures. Also time to HLD was reviewed for all procedures were recorded. Then, a model of disposable bronchoscope was used to simulate different contamination times. Contamination was performed using 1011 colony count of Pseudomonas, Vancomycin resistant Enterococcus fecium and Klebsiella producing carbapenemase. Then processing using HLD with or without sterilization. Also after applying longer soaking in enzymatic cleaning. Cultures were conducted using flush, brush, flush technique.
The majority of endoscopic procedures lasting more than 60 minutes were ERCP. Time to processing was particularly problematic for bronchoscopes as they are used 24/7. The majority of bronchoscopes performed after hours and weekend s are processed later than 2 hours from end of procedure. Positive endoscopic cultures were almost a Gram-negative phenomenon with no Gram positive recovered after processing. Sterilization did not have any advantage over HLD. Contamination for over 2 hours was critical in worse outcome. Longer soaking prior to HLD seems very promising in adequate endoscope processing.
Twenty disposable bronchoscopes were contaminated for different times and processed using HLD, sterilization and longer soaking. The preliminary results show that only longer soaking is effective in reliably eliminating bacteria from scopes. Processing and procedure times are easy targets for adequate processing.
R. Hariri, None
J. Ferrelli, None
L. Mckibben, None