The ED50 and ED95 of esketamine for preventing early postoperative pain in patients undergoing laparoscopic cholecystectomy: a prospective, double-blinded trial.

Background: This study aims to estimate the safety, efficacy, and median effective dose (ED50) of esketamine for preventing early postoperative pain in patients undergoing laparoscopic cholecystectomy.

Methods: 54 patients undergoing laparoscopic cholecystectomy were prospectively randomized into two groups (group C and group E). Different doses of esketamine were intravenously administered before the skin incision in Group E.