Effectiveness of Premedication with Pronase for Visualization of the Mucosa during Endoscopy: A Randomized, Controlled Trial

BACKGROUND/AIMS Gastric mucus should be removed before endoscopic examination to increase visibility. In this study, the effectiveness of premedication with pronase for improving visibility during endoscopy was investigated. METHODS From April 2010 to February 2011, 400 outpatients were randomly assigned to receive endoscopy with one of four premedications as follows: dimethylpolysiloxane (DMPS), pronase and sodium bicarbonate with 10 minutes premedication time (group A, n=100), DMPS and sodium bicarbonate with 10 minutes premedication time (group B, n=100), DMPS, pronase and sodium bicarbonate with 20 minutes premedication time (group C, n=100), and DMPS and sodium bicarbonate with 20 minute premedication time (group D, n=100). One endoscopist, who was unaware of the premedication types, calculated the visibility scores (range, 1 to 3) of the antrum, lower gastric body, upper gastric body and fundus. The sum of the scores from the four locations was defined as the total visibility score. RESULTS Group C showed significantly lower scores than other groups (p=0.002). Group C also had the lowest frequency of flushing, which was significantly lower than that of group D. Groups C and D had significantly shorter durations of examination than groups A and B. CONCLUSIONS Using pronase 20 minutes before endoscopy significantly improved endoscopic visualization and decreased the frequency of water flushing.