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

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.

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 was 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.

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 the 77 ready-for-use respiratory and gastrointestinal endoscopes assessed, 37 (48.1%) showed evidence of retained moisture.

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.