ACUTE PAIN SECTION Original Research Article Pre-Incisional Analgesia with Intravenous or Subcutaneous Infiltration of Ketamine Reduces Postoperative Pain in Patients after Open Cholecystectomy: A Randomized, Double-Blind, Placebo-Controlled Studypme_1205

Background. In literature, there is controversy on the use of ketamine for management of postoperative pain. The aim of the present study was to evaluate the efficacy of pre-incisional intravenous or subcutaneous infiltration of ketamine on postoperative pain relief after open cholecystectomy. Methods. One hundred twenty patients, aged 18–60 years, scheduled for open cholecystectomy was enrolled in this randomized, double-blind, placebocontrolled study. Patients were divided into four groups of 30 each and received subcutaneous infiltration of ketamine 1 mg/kg (group KS1), subcutaneous infiltration of ketamine 2 mg/kg (group KS2), intravenous ketamine 1 mg/kg (group KI), or subcutaneous infiltration of normal saline 20 mL (group C) before surgery. Visual analog scale (VAS) values and analgesic consumption were evaluated for 24 hours after operation. Results. VAS scores were significantly lower at arrival to the postanesthesia care unit, 15 and 30 minutes in Group KS1, Group KS2, and Group KI compared with Group C (P < 0.05). In Group KS2, VAS scores were significantly lower than Group KS1 (P < 0.05). Postoperative VAS scores were significantly lower at 1, 2, 3, 4, 8, 12, and 24 hours after operation in Group KS1, Group KS2, and Group KI compared with Group C (P < 0.05). In Group KS2, VAS scores were significantly lower than Group KS1 (P < 0.05). Conclusion. A 2 mg/kg dose of subcutaneous infiltration ketamine or 1 mg/kg dose of intravenous ketamine given at approximately 15 minutes before surgery provides an adjunctive analgesia during 24 hours after surgery in patients undergoing cholecystectomy surgery.