Intraperitoneal magnesium sulphate plus bupivacaine for pain relief after laparoscopic cholecystectomy

Abstract

Background: Multimodal analgesia is necessary for management of pain after laparoscopic cholecystectomy. Magnesium sulphate is a new emerging drug for management of acute pain. This study was performed to study the analgesic efficacy of intraperitoneal bupivacaine and bupivacaine plus magnesium sulphate for postoperative pain relief after laparoscopic cholecystectomy. Methods: At the end of laparoscopic cholecystectomy, 60 patients were randomized to one of the following groups: bupivacaine group receiving intraperitoneal instillation of 30 ml of 0.25% bupivacaine and magnesium sulphate group receiving intraperitoneal instillation of 0.25% bupivacaine plus 50 mg/kg magnesium sulphate to total volume of 30 ml. Postoperative pain was evaluated by using visual analogue scale (standard Visual Analogue Scale pain score of 0-10). Time duration of first analgesia demanded was noted and rescue analgesic was given as tramadol 50 mg intravenously and on demand. Pain, Visual Analogue Scale score and total analgesic consumption was recorded for 24 hours and analysed. Results: The patients who were given intraperitoneal bupivacaine plus magnesium sulphate at the end of surgery had better pain relief in first 24 hours, Visual Analogue Scale score of 0-5 compared to sole bupivacaine group who had Visual Analogue Scale score of 3-7. The magnesium sulphate group had longer pain free period of average 5.53±4.33 hours after surgery compared to 3.16±1.59 hours in sole bupivacaine group. Total analgesic consumption in magnesium sulphate group was also less compared to bupivacaine group (125.0±36.5 and 75.0±25.0 in bupivacaine and magnesium sulphate group respectively). All the results show highly significant differences between the groups. Conclusion: The combined instillation of bupivacaine and magnesium sulphate into the peritoneal cavity at the end of laparoscopic surgery renders patients better pain control and less consumption of analgesics in first 24 hours compared to sole bupivacaine group. DOI: http://dx.doi.org/10.3126/jkmc.v1i1.7251 Journal of Kathmandu Medical College, Vol. 1, No. 1, Issue 1, Jul.-Sep., 2012 pp.21-25