According to the CDC, healthcare-acquired infections affect 5-10% of the patient population, resulting in approximately 100,000 deaths and generating nearly $20 billion in healthcare costs per year. One potential vector for infectants is exploratory scopes. Total rates of scope-related infections are not well documented, but, in January 2016, according to FDA’s Manufacturer and User Facility Device Experience database, eight patients suffered an E. coli infection after endoscopic procedures, and, of those eight, two patients died.
In a 2018 article, “Residual moisture and waterborne pathogens inside flexible endoscopes: Evidence from a multisite study of endoscope drying effectiveness” published in the American Journal of Infection Control, 2018, epidemiologist Cori Ofstead and colleagues conducted a multisite, observational study in three multispecialty hospitals accredited by The Joint Commission to assess probe disinfection and drying practices and determine the effectiveness of different procedures.
Of the 45 examined endoscopes, 47% of channels were observed to have water droplets, and 49% contained water, indicated by test strips. ATP levels of greater than 200 relative light units were found in 22% of scopes, ranging from 5% to 46% by facility, and microbial growth was detected in 71% of endoscopes. Researchers also noted defects on all 45 reprocessed endoscopes, including “discoloration, white or black residue, scratches, gouges, non-intact channel lining, debris inside endoscopes, damaged distal ends, insertion tube buckling, and dented channels,” according to the report.
Two of the sites in the study employed alcohol flushes and vertical storage, to allow water to drain from the scopes, with brief bursts of forced air to blow out liquid. At those sites, over 80% of scopes contained residual liquid. At a third site, the same processes were employed; however, the short bursts of air were replaced with 10 minutes of forced air drying, resulting in a 95% dry channel rate. But, despite the dryness of those scopes, waterborne pathogens were still detected.
A potential explanation for this was the state of rinse water filters in the facility’s sterilizers. Even though personnel complied with manufacturer guidelines on the frequency of changing filters, the researchers observed significant brown discoloration and mold. Additionally, Ofstead et al. referenced a study demonstrating that the amount of positive cultures is greater on scopes when procedural volumes increase, but the incidence could be greatly reduced by more frequent replacement of filters.
At two of the study sites, staff had intentionally disabled the automatic endoscope reprocessing equipment’s automated cleaning cycles to increase reprocessing turnaround time—compromising the effectiveness of the cleaning procedures.
Other factors contributing to less than optimal reprocessing may be the prevalent use of silicone-containing lubricants and defoaming agents used during procedures. Scope manufacturers warn that reprocessing effectiveness can be compromised when scopes come into contact with such compounds. Also, the researchers recommend attenuating the use of simethicone, which is used during endoscopic procedures to reduce foam in the GI tract that can obscure visibility. Simethicone is not removed during reprocessing and can contribute to microbial growth and biofilm.
Ofstead and her colleagues concluded that a combination of practices could potentially improve reprocessing effectiveness: changing filters more frequently than indicated by manufacturers, especially during periods of high procedure volumes; adhering to manufacturer settings for automated cleaning cycles; increasing forced air drying time to a minimum of 10 minutes; reducing the use of silicone-based products and simethicone; and replacing high-level disinfection cleaning with sterilization for all scopes. Additional, they recommend considering single-use scopes when feasible. Finally, Ofstead strongly suggests that hospital environmental health and safety managers become active in the Institute for Safety and Health Management, which provides advanced guidelines and certifications that go well beyond typical industry standards.
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