Determination of the optimal time for premedication with pronase, dimethylpolysiloxane, and sodium bicarbonate for upper gastrointestinal endoscopy.

Goals and Background: Premedication with pronase, dimethylpolysiloxane, and sodium bicarbonate improves visibility during upper gastrointestinal (UGI) endoscopy. However, the optimal time for this combination to take effect is unknown. We investigated the optimal time of pre-UGI endoscopy medication.
Study: A randomized, investigator-blind, controlled trial. The 300 patients who were to receive premedication were randomized into 3 groups according to the following medication time before UGI endoscopy: 10 minutes (group A, n=98), 10 to 30 minutes (group B, n=97), and 30 minutes premedication (group C, n=99). Visibility scores (range, 1 to 4, with lower scores indicating better gastric mucosal visibility) were assessed for the antrum, lower body, upper body, and fundus and compared, including the sum of the scores, between the 3 groups.
Results: Group B had significantly lower visibility scores for the lower body, upper body, and fundus than group C (P=0.001, 0.009, and 0.002, respectively). Group A obtained significantly lower scores for the antrum and lower body than group C (P=0.007 and 0.005, respectively). The total visibility scores of groups A and B were significantly lower compared with those of group C (P=0.001, 0.003, respectively).
Conclusions: Administration of pronase, dimethylpolysiloxane, and sodium bicarbonate within 30 minutes before UGI endoscopy significantly improved endoscopic visualization. However, the optimal time to achieve the best visibility was between 10 to 30 minutes before UGI endoscopy.