DS 37 - Examining Endoscope Dryness Following Automated Reprocessing: A Stripped Endoscope Model

Background: Drying of the internal channels of endoscopes is an essential step of high-level disinfection that helps prevent the growth of water-borne pathogens or prepares the device for adequate sterilization with vaporized hydrogen peroxide or ethylene oxide. Currently there are limited methods to measure residual moisture, which may harbor pathogens and foster bacterial growth and biofilm development. The aim of this study is 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 were 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 stripped endoscopes 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 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.