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.