Comparison of the effects of intraperitoneal magnesium sulphate and bupivacaine with that of bupivacaine alone on the duration of postoperative analgesia in laparoscopic sterilisation : A prospective observational study

Abstract Background and Aims: Pain may cause postoperative pulmonary morbidity and protracted recovery in laparoscopic sterilisation. Apart from parenteral analgesics, intraperitoneal instillation of local anaesthetics and NMDA receptor antagonist, MgSO₄ may be tried for better pain relief. This study was aimed to evaluate the postoperative pain relief of intraperitoneal MgSO4 with bupivacaine compared to bupivacaine alone in patients undergoing laparoscopic sterilisation and assess its safety. Methods : Seventy females undergoing laparoscopic sterilisation were divided into two groups. Group B received 40ml 0.25% bupivacaine and group MB received 40ml 0.25% bupivacaine and magnesium sulphate (MgSO₄) 30 mg kg⁻¹intraperitoneally at the end of the surgery. Postoperative pain was assessed using verbal numeric pain rating scale (NPRS). Duration of postoperative analgesia, total analgesic consumption, hemodynamics, and adverse effects were assessed for 12 hours postoperatively. Results Duration of postoperative analgesia was prolonged in group MB (7.1142.259h) compared to group B (3.086h) (P =0.000). Pain scores were significantly lower in group MB in 1st, 2nd and 3rd hour postoperatively (P =0.000 – 0.001). Total paracetamol consumption in first 12h postoperatively in group MB was lower (0.714gm) compared to group B (1.343gm) (P < 0.001). Conclusions Intraperitoneal instillation of bupivacaine with MgSO₄ is an excellent mode of postoperative analgesia for laparoscopic sterilisation.