Efficacy and opioid-sparing effect of interpleural bupivacaine in patients undergoing laparoscopic cholecystectomy: Prospective observational study (Running title: Efficacy of inter-pleural bupivacaine in laparoscopy)

Introduction: Laparoscopic cholecystectomy is considered minimally invasive, but pain following laparoscopy is moderate to severe, leading to increased morbidity and length of hospital stay. Various medications, including opioids, NSAIDs, and techniques like intraperitoneal local anesthetic infiltration, are used. In this study, we investigated interpleural block with bupivacaine for pain relief following laparoscopic cholecystectomy. Methods: A total of 60 patients were included in the study. 30 patients received 20 ml of 0.5% interpleural bupivacaine (group 1), and 30 patients recieved 20 ml of 0.9% normal saline (group 2). We recorded visual analog score (VAS), vital signs, and postoperative opioid requirements. Tramadol (2 mg/kg) was rescue medication if VAS ≥ 5. Results: Significant difference between study groups was recorded among VAS scores measured at 30 minutes, 1, 2, 6, 10, and 12 hours (p value < 0.05). The difference in VAS scores at 15 minutes and 14 hours between study groups was insignificant (p value > 0.05). The number of patients who received tramadol was 9 (30%) patients in group 1 and 29 (96.7%) patients in group 2. The difference in proportion for tramadol intake at 6 hours was significant among study groups (p-value < 0.05). Conclusion: Interpleural bupivacaine 20 ml of 0.5% used as analgesia reduces post-operative opioid requirement following laparoscopic cholecystectomy. Hence interpleural block can be safely used as a regional technique for pain relief following laparoscopic cholecystectomy.