Effect of Intrapleural Meperidine on Post-Operative Pain after Open Cholecystectomy

Background: Post-operative pain after open cholecystectomy can result in increased oxygen consumption, atelectasis, pneumonia, decreased vital capacity, and increased morbidity and mortality. The aim of this study was to compare the analgesic effects of intrapleural meperidine and intravenous morphine in controlling post-cholecystectomy pain. Materials and Methods: In a double-blinded randomized clinical trial, 72 patients who were candidate for elective open cholecystectomy, were divided randomly into two groups based on accidental randomized numbers. Anesthesia technique was precisely the same for all patients. At the end of surgery, 50 mg of meperidine (diluted in 20 cc normal saline) was injected intrapleurally for meperidine group patients; whereas, 0.1 mg/kg intravenous morphine was injected intravenously in control group. Onset of pain and total dose of rescue analgesic were measured. Results: In order to obtain a Numerical Rating Scale (NRS) <3, the difference in morphine consumption up to 12 hours in two groups (4.4 ±1.7 mg in meperidine group & 5±2 mg in control group) was not statistically different. However, the first request for analgesia in meperidine group was delayed significantly longer than the control group (146.6 ±6.8 minutes in meperidine group & 40 ±1.8 minutes in control group). Conclusion: A single injection of intrapleural meperidine can delay the first request for analgesia in open cholecystectomy compared to intravenous morphine.