1166 A NEW DESIGNED DUODENOSCOPE WITH DETACHABLE DISTAL CAP CAN SIGNIFICANTLY REDUCE ORGANIC RESIDUE CONTAMINATION AFTER REPROCESSING EVALUATED BY ADENOSINE TRIPHOSPHATE TEST

Abstract

Because of its complex structures with an elevator mechanism, cleaning and disinfection of the duodenoscope are more difficult than other endoscopes. Despite high level disinfection (HLD) protocol, several outbreaks of multidrug resistance bacterial contamination (BC) of the duodenoscope with fixed distal cap were reported. A new designed duodenoscope with detachable distal cap (ED 580XT, Fujifilm, Tokyo, Japan) may have advantage over the conventional duodenoscope with fixed distal cap by allowing the brush to access the backside of the elevator. However, comparative data on BC and organic residue of the conventional duodenoscope vs. the duodenoscope with detachable distal cap after HLD is lacking. During December 2018-April 2019, 108 used duodenoscopes with detachable distal cap underwent HLD and were enrolled 1:1 into group A and group B. In group A (n=54), the distal cap of duodenoscope was detached before manual cleaning (figure 1A and 1B). Whereas in group B (n=54), the distal cap was not detached before manual cleaning (figure 1C and 1D) in order to imitate the conventional duodenoscope with fixed distal cap. After single round of HLD, sample was collected from the elevator site (ES) with swab rotation and submitted for culture and then rapid BC and organic residue evaluation were done by analyzing for Relative Light Units (RLU) that read by adenosine triphosphate (ATP) test (Clean-Trace Surface ATP, 3M, MN, USA). Based on our previous data that demonstrated 100% sensitivity and 100% negative predictive value for BC, the ATP threshold at 40 RLU was used in this study. We compared the proportion of potential BC and organic residue evaluated by rapid ATP test and confirmed BC evaluated by bacterial culture in group A vs. group B after HLD. After HLD, using the ATP threshold at 40 RLU as the cut-off value, the proportion of potential BC and organic residue in group A was significantly lower than that of in group B [20/54 (37%) vs. 41/54 (75.9%); p<0.001] (Table 1). Mean ATP value in group A was also significantly lower than that of in group B [45.2 RLU (range 9-209) vs. 151.9 RLU (range 19-653); p<0.001). In group B, one culture sample was found to have non-pathogenic BC (coagulase negative Staphylococcus). Pathogenic BC confirmed by culture was not documented in the both groups. Since a new design, detachable duodenoscope allows brushing the backside of elevator, it can reduce residual organic material confirmed by the ATP test. Although no pathological organism was found after HLD in both groups, BC from skin and membrane flora was still detected in duodenoscope with fixed distal cap.Table 1Comparison of ATP testing and culture results between the duodenoscope with detachable distal cap vs. the duodenoscope with fixed distal cap after HLDView Large Image Figure ViewerDownload Hi-res image Download (PPT)