How effective are the alcohol flush and drying cycles of automated endoscope reprocessors? Stripped Endoscope model.

BACKGROUND: Effective drying of the internal channels of endoscopes is essential to prevent the growth of water-borne pathogens and to assure adequate sterilization with vaporized hydrogen peroxide or ethylene oxide. The aim of this study was 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 SE 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.