Analgesic and hemodynamic effects of intravenous magnesium sulfate infusion versus lidocaine infusion in patients undergoing thyroid surgery for toxic goiter resection: a randomized controlled study

Background Anesthesia for toxic goiter resection is challenging as manipulation of the thyroid gland and inadequate postoperative pain control could lead to hemodynamic instability due to stress and a neurohormonal response. Both magnesium sulfate and lidocaine are known for their analgesic effects and decreasing stress response. Herein, we compared the previous two medications regarding intraoperative hemodynamics and postoperative analgesia. Patients and methods 57 patients who underwent toxic goiter resection were enrolled in this prospective randomized trial (group M received magnesium sulfate, group L received lidocaine, and group C received normal saline). Intraoperative hemodynamics and postoperative analgesic profiles were assessed. Results Both injection groups expressed significantly lower pain scores compared with control group at Post anaesthesia care unit (PACU) and one-hour postoperative. Postoperative fentanyl consumption was significantly lower, and the time to first analgesic request was significantly prolonged in Magnesium and Lidocaine groups than in the control group. The previous beneficial effects were more prominent in the Magnesium Group compared with the Lidocaine Group. There was no significant difference in mean arterial pressure (MAP) and heart rate (HR) among the three study groups at the baseline, after the end of infusion, and after induction. Nonetheless, there was a significant rise in mean arterial pressure and heart rate values in the control group compared with the Magnesium and Lidocaine Groups with intubation and during the first hour of surgery. Conclusion Both magnesium sulfate and lidocaine have beneficial hemodynamic stabilizing and analgesic effects in patients undergoing thyroid surgery for toxic goiter, with a slight superiority for magnesium.