Effect of intraperitoneal bupivacaine vs magnesium sulfate on early postoperative outcomes after laparoscopic sleeve gastrectomy: a randomized clinical trial.

Background: Obesity is now recognized as a major global health challenge, associated with various comorbidities. Sleeve gastrectomy, a minimally invasive surgery, is accompanied by short-term complications such as postoperative pain, which undermines the advantages of this technique. Therefore, this study aims to compare the efficacy of intraperitoneal instillation with bupivacaine versus magnesium sulfate on early postoperative outcomes in patients undergoing sleeve gastrectomy.

Materials and methods: This study was conducted in Iran as a randomized controlled trial. A total of 105 patients candidates for laparoscopic sleeve gastrectomy were divided into three groups of 35 patients each: Group A(bupivacaine), Group B (magnesium sulfate), and Group C (normal saline). The VAS was used to assess postoperative pain in the first 24 h after surgery. Data were analyzed using SPSS version 16.

Results: Based on the results of the Kruskal-Wallis test, there was a significant difference in abdominal pain levels among the study groups at 1, 2, 4, and 6 h post-surgery (P-value < 0.05). Abdominal pain levels in both the bupivacaine and magnesium sulfate groups were significantly lower than those in the control group during the initial postoperative hours; however, no significant difference was observed between the bupivacaine and magnesium sulfate groups. Total rescue analgesic requests in the bupivacaine group was significantly lower than that in the control group (P-value = 0.010), with no significant difference observed between the bupivacaine and magnesium sulfate groups. Neither drug caused a significant difference in postoperative shoulder pain levels or the incidence of postoperative nausea and vomiting (P-value = 0.562).

Conclusion: This study revealed that intraperitoneal administration of bupivacaine at 1, 2, and 4 h postoperatively, and magnesium sulfate at 2, 4, and 6 h postoperatively, significantly reduced pain in patients undergoing sleeve gastrectomy compared to those who didn't receive these analgesics. The lack of efficacy of both interventions in alleviating shoulder pain underscores the necessity of investigating alternative approaches to achieve comprehensive pain management in this patient population.

Trial registration: Clinical Trial Registration  https://www.irct.ir/ , identifier (IRCT20230129057271N2).