Bacterial contamination and organic residue after reprocessing in duodenoscopes with disposable distal caps compared with duodenoscopes with fixed distal caps: a randomized trial

Abstract

Newly designed duodenoscopes with disposable distal caps have been developed for better cleaning and preprocessing to reduce the risk of bacterial contamination (BC). We compared BC and organic residue of duodenoscopes with disposable distal caps and duodenoscopes with fixed distal caps after manual cleaning and high-level disinfection (HLD). Four hundred duodenoscopes were randomized into group A (fixed distal caps, n= 200) and group B (disposable distal caps, n= 200). After manual cleaning, samples from the elevator were submitted for culture. An adenosine triphosphate (ATP) test was performed for organic residue evaluation. Based on our previous data, ATP< 40 relative light units (RLUs) had 100% sensitivity with 100% negative predictive value to confirm no BC after reprocessing. After manual cleaning, group A had a higher BC rate (14% vs 7%, P= .02), a higher proportion of duodenoscopes with ATP≥ 40 RLUs (73.5% vs 57%, P= .001), and a higher mean of ATP level (226.6 vs 82.0 RLUs, P< .001) compared with group B. After HLD, the proportion of potential BC (ATP≥ 40 RLUs) in group A was 2.7 times higher than group B (4% vs 1.5%, P= .13). Mean ATP level after HLD in the 2 groups was significantly lower than before the HLD procedure (group A, 24.2 vs 226.6 RLUs [P< .001]; group B, 20.4 vs 82.0 RLUs [P< .001], respectively). After manual cleaning, duodenoscopes with disposable distal caps had significantly lower BC and organic residue than duodenoscopes with fixed distal caps. Only a few duodenoscopes from each group did not pass the ATP threshold after HLD.