Comparative evaluation of intraperitoneal bupivacaine, magnesium sulfate and their combination for postoperative analgesia in patients undergoing laparoscopic cholecystectomy

Abstract

Background: Various multimodal techniques have been employed time and again to allay visceral pain after laparoscopic cholecystectomy. Aim: The aim of this study was to assess and compare the postoperative pain relief in patients undergoing laparoscopic cholecystectomy with intraperitoneal administration of bupivacaine, magnesium sulfate and their combination. Materials and Methods: Patients were randomly divided into four groups of 20 each. Patients in group I "C" received 50 ml of 0.9% saline, group II "B" received 50 ml of 0.25% bupivacaine, group III "M" received 50 ml of 30 mg/kg magnesium sulfate, while patients in group IV "MB" received 0.125% of bupivacaine with 15 mg/kg of magnesium sulfate to a total volume of 50 ml after surgery. Postoperatively pain was assessed using visual analog scale (VAS) and postoperative pain (VAS > 3) was managed with intravenous tramadol 50 mg. Time to the first request of analgesia, the total number of analgesic doses of tramadol, the incidence and severity of postoperative shoulder pain in 24 h and presence of complications if any were noted. Results: Demographic profile of patients of all the four groups was comparable and statistically nonsignificant. Intraperitoneal instillation of 0.25% bupivacaine provided longest duration of analgesia for 541.5 ΁ 131.48 min with a significant reduction in the number of doses of intramuscular tramadol in 24 h. Intraperitoneal instillation of 30 mg/kg magnesium sulfate provided analgesia for 82.25 ΁ 35.37 min with no significant reduction in a number of doses of intramuscular tramadol in 24 h when compared to control. Intraperitoneal instillation of mixture of bupivacaine and magnesium sulfate in reduced doses, that is, 0.125% bupivacaine and 15 mg/kg magnesium sulfate provided analgesia for 305 ΁ 65.64 min with a significant reduction in a number of doses of intramuscular tramadol in 24 h. There was reduced incidence and severity of shoulder pain, which was comparable in all the four groups. No significant side-effects were seen in any of the groups. Conclusion: Intrape-ritonel administration of bupivacaine, magnesium sulfate and their combination in reduced doses provides effective postoperative analgesia in laparoscopic cholecystectomy patients though their combination when the doses of both the drugs were reduced to half was less effective than bupivacaine group alone. Furthermore, bupivacaine and magnesium sulfate serve as useful adjuncts to postoperative analgesics.