Study Shows Endoscope Processing Practices Often Insufficient

Posted March 22, 2017

Current techniques to clean and disinfect flexible endoscopes prior to reuse are not consistently effective, according to a study published in the February issue of the American Journal of Infection Control. These results suggest that even rigorous reprocessing practices may not be sufficient to ensure endoscopes, such as duodenoscopes and colonoscopes, are free from disease-causing organisms before they are used on the next patient.

"Understanding issues with the effectiveness of reprocessing techniques is critically important as institutions seek to improve the quality of endoscope cleaning and disinfection,” said lead study author Cori L. Ofstead, president and CEO of Ofstead & Associates, Inc., in a press release. “Even though top-notch methods were used, the endoscopes in this study had visible signs of damage and debris, and tests showed a high proportion were still contaminated.”

With endoscopes linked to a number of antibiotic-resistant and other infections, reprocessing guidelines now recommend a greater emphasis on visual inspections of the devices’ channels and ports, as well as routine tests for biochemical markers, such as protein, hemoglobin, and adenosine triphosphate (ATP) to verify the effectiveness of cleaning.

To see whether these more rigorous techniques improved endoscope cleanliness, the researchers assessed 20 endoscopes from a single ambulatory surgery center three times over a seven-month period. The devices were either reprocessed according to current guidelines or cleaned twice before undergoing high-level disinfection. The researchers then examined the endoscopes with a tiny camera and assessed residual contamination levels using microbial cultures and biochemical tests.

At the conclusion of the study, the researchers found visual irregularities, such as discoloration, scratches, and channel debris, in all 20 endoscopes, usually on the distal ends of the devices. Additionally, 12 of the 20 reprocessed devices (60%) harbored microbes and about 20% in each group exceeded post-cleaning benchmarks for ATP and protein residue.

“Protein residues may not be removed despite vigorous cleaning, and brushing may spread out protein and increase its adherence to surfaces,” the researchers wrote. “This study demonstrated that more rigorous reprocessing practices might not be sufficient to ensure that patient-ready endoscopes are free from residual contamination, particularly when the endoscope has defects that could harbor organic debris and biofilm.”

According to the researchers, these findings bolster the need for sterilization and reprocessing personnel to conduct routine visual inspections and cleaning verification tests to ensure all endoscopes are free from damage and debris before they are used.