Effect of intravenous versus intraperitoneal magnesium sulfate on hemodynamic parameters and postoperative analgesia during laparoscopic sleeve gastrectomy-A prospective randomized study

Background and Aims: Hemodynamic changes to pneumoperitoneum and postoperative pain can be detrimental in obese patients; we investigated whether intravenous (IV) or intraperitoneal (IP) magnesium sulphate (MgSo(4)) administration could attenuate the hemodynamic stress response to pneumoperitoneum and improve postoperative pain control after laparoscopic sleeve gastrectomy (LSG). Material and Methods: In total, 120 patients scheduled for LSG were randomized to either, control group (Group C, IV and IP saline), Group I (IV 30 mg/kg MgSo(4)), or Group P (IP 30 mg/kg MgSo(4)). Outcome variables were mean arterial pressure (MAP), heart rate (HR), postoperative pain score, total analgesic consumption, and incidence of adverse events. Results: MAP and HR were significantly lower in Groups I and P than that in control group. Pain score was better in Groups I and P than in control group up to 2 h postoperative (P = 0.023, 0.010, respectively); it was significantly lower in Group P than other two groups at 4 h postoperative (P<0.001). Significantly, reduced postoperative analgesic consumption with delayed onset to first analgesic request were observed in magnesium groups compared to control (P = 0.001, respectively). Moreover, onset to first analgesic request was longer in Group P than Group I (P = 0.001). No serious side effects were noticed. Conclusion: The IV and IP administration of MgSo(4) significantly attenuated the circulatory response to pneumoperitoneum and reduced postoperative pain as well as opioid consumption as compared to controls in obese patients undergoing LSG with no serious adverse effects.