819 - How effective is alcohol flush and drying cycle of automatic endoscope reprocessor (AER): Stripped Endoscope (SE) model

Background: Endoscopic designs are more ergonomic and technically sophisticated than ever.  Endoscope transmitted infections continues despite scrutiny and optimization of disinfection processes.  Effective endoscopic dryness has been largely overlooked, even though it is paramount for prevention of water-borne pathogens accumulating after high level disinfection (HDL).  Additionally, complete dryness is required to achieve sterilization.  The aim of this study is to evaluate the dryness of the endoscopes after routine a routine disinfection process.

Methods: Three endoscopes were stripped from their outer sheaths to allow for visual inspection of the inside channels.  SE were processed as per usual practice.  After HLD in an automatic endoscope reprocessor (AER) that included an alcohol flush and drying cycle, SE were hung and observed for any water within the channels. SE were flushed with filtered compressed air.  Dryness was monitored visually and by feeling for the impact of water spray at the distal tip of SE.  Dryness of the channels before and after air flush was observed for the three SE for three trials each.

Results: All the SE were grossly wet after HLD despite the AER’s alcohol flush and drying cycle. Hanging vertically had no effect on the narrow diameter channels.  Applying compressed air to each channel was effective for drying the channels based on visual inspection and water emission from the distal tip of the SE.  The filtered compressed air had a flow rate of 20 L/minute for an average of 2 minutes to assure complete dryness.  The nozzle for applying the filtered compressed air was ill-fitting to the openings of the cylinders and ports on the control handle, making it difficult to get a good seal for applying the filtered compressed air.

Conclusion: The AER’s drying cycle was not effective for drying endoscope channels.  Vertical hanging had limited efficacy on endoscopic dryness.  The application of filtered compressed air to individual channels was effective for drying the channels.  This SE model was useful and direct for assessing the degree of moisture inside the channels.  The application of filtered compressed air should be an essential step in endoscopic reprocessing regardless of the need for sterilization.