Comparison of Prophylactic Intravenous Magnesium Sulfate with Tramadol for Postspinal Shivering in Elective Cesarean Section: A Placebo Controlled Randomized Double-blind Pilot Study

BACKGROUND AND AIMS: Cesarean sections are performed mostly under spinal anesthesia. Shivering is one of the distressing complications. The aim of the study was to compare the efficacy of intravenous (i.v) magnesium sulfate and tramadol with placebo (normal saline) on postspinal shivering in elective cesarean section when used as prophylaxis. METHODS: One hundred and thirty-five pregnant women between 18 and 35 years age, belonging to the American Society of Anesthesiologists’ physical Status II, undergoing elective cesarean section under spinal anesthesia were enrolled into the study. Patients belonging to Group C (control group, n = 45) received isotonic saline 100 mL i.v, Group T (tramadol group, n = 45) received tramadol 0.5 mg/kg in 100 mL isotonic saline i.v, whereas those in Group M (magnesium sulfate group, n = 45) received magnesium sulfate 30 mg/kg in 100 mL isotonic saline i.v after administering spinal anesthesia. Incidence and grades of shivering were noted. Data were analyzed using one-way ANOVA test and Chi-square test. RESULTS: The incidence of shivering in Group C, Group T, and Group M were 67.5%, 43.9%, and 39%, respectively. The incidence of shivering in Group M and Group T was significantly low when compared to Group C (P = 0.008; P = 0.026), whereas there was no statistically significant difference between Groups T and M (P = 0.654). CONCLUSION: Magnesium sulfate and tramadol significantly reduce the incidence of shivering compared to placebo when used as prophylaxis in pregnant women undergoing cesarean section under spinal anesthesia. Magnesium sulfate reduces the severity of the shivering.