Use of a drying cabinet is considered a best practice in endoscope reprocessing for reducing infection risk.1-3 Yet no standards specify which type of cabinet — standard or automated — yields a more effectively dry and safe endoscope.
A recent study, published in AJIC, set out to measure drying effectiveness of standard vs. automated drying cabinets. Researchers found that using a standard cabinet is not as efficient in its ability to dry endoscopes before storage compared to an automated cabinet. The automated cabinet using compressed instrument-grade air dried internal channels in one hour and external surfaces in three hours. The standard cabinet still had fluid internally at 24 hours and was only able to dry the external surfaces in 24 hours.
What’s behind the differences in drying performance?
A standard storage cabinet without compressed or high-efficiency particulate air (HEPA) doesn’t provide direct airflow through the endoscope’s internal channels or any airflow over external surfaces. The endoscopes hang in the vertical position, with the intent that gravity will help drain any residual fluid. Vertically hanging endoscopes pose a higher risk of damage because they can swing freely and crash into each other. Damaged endoscopes are harder to clean.
By contrast, an automated drying and storage cabinet allows a constant flow of compressed instrument-grade air. The compressed air passes through a filter before circulating through each endoscope channel. Rather than hanging vertically, endoscopes are placed in a cassette system and are hooked up to a connection block to allow endoscopes to dry and store horizontally. The cabinet also circulates air to enhance the drying of the endoscopes’ external surfaces.
Why is air important?
The key difference between the two is air. But not all air is the same. There are three critical factors associated with air quality — particulate filtration, moisture and hydrocarbons — that can enhance drying time consistency and ensure a safe, patient-ready endoscope.
HEPA sets an industry standard for particulate filtration, but it does not control for moisture or hydrocarbons. In contrast, instrument-grade air is a medical gas that falls under the general requirements for healthcare facilities defined by the National Fire Protection Agency (NFPA). It is not respired, and it is compliant with quality standards for instrument air.4 Unlike HEPA, instrument-grade air is filtered to be free of liquids and hydrocarbon vapors.
With all the different factors associated with endoscope reprocessing and drying, utilizing an air that controls as many factors as possible will allow for increased consistency and quality. When you combine quality air with the right drying cabinet, you create the ideal procedure to produce safe, patient-ready endoscopes.
It’s essential to know the facts about the critical role of drying in minimizing infection risk.
Darren Dahlin is the Clinical Education Director at Medivators, the medical division of Cantel
- Thaker AM, Kim S, Sedarat A, et al. Inspection of endoscope instrument channels after reprocessing using a prototype borescope. Gastrointest Endosc 2018;88:612-619.
- Barakat MT, Girotra M, Huang RJ, Banerjee S. Scoping the scope: endoscopic evaluation of endoscope working channels with a new high-resolution inspection endoscope (with video). Gastrointest Endosc 2018;88:601-611.
- Ofstead CL, Wetzler HP, Heymann OL, Johnson EA, Eiland JE, Shaw MJ. Longitudinal assessment of reprocessing effectiveness for colonoscopes and gastroscopes: results of visual inspections, biochemical markers, and microbial cultures. Am J Infect Control 2017;45:e26-33.
- ANSI/ISA S-7.0.01