To study the efficacy of intravenous infusion of magnesium sulfate in the Indian population during epidural anesthesia using 0.5% bupivacaine for postoperative pain in infra-umbilical surgery

Abstract

Objectives: Infra-umbilical surgeries are associated with moderate-to-severe pain postoperatively. Intravenous infusion of magnesium sulfate during epidural anesthesia was given which prolonged the duration of analgesia and decreased doses of analgesics. As hardly any study has been done on the Indian population, this study evaluated the effectiveness of magnesium sulfate infusion on quality of epidural anesthesia, postoperative analgesic requirements, and incidence of nausea and vomiting in the patients undergoing any infra-umbilical surgery. Methodology: A prospective randomized controlled double-blind study was carried out at a tertiary level hospital in India in seventy patients scheduled for infra-umbilical surgeries belonging to the American Society of Anesthesiologists I and II. Patients were randomized into two groups of 35 each. Group MG patients received MgSO4 50 mg/kg in 100 ml NS in 10 min, followed by an infusion of MgSO4 10 mg/kg/h in 100 ml NS over 1 h. Group NS received 100 ml NS in 10 min, followed by an infusion of 100 ml NS over 1 h. Results: The onset time of sensory and motor block was similar in both the groups, but the duration of sensory and motor block and duration of analgesia was more in MG group compared to NS group. The mean sensory onset time in MG group was 9.09 ± 2.23 min and 9.34 ± 2.29 min in NS group, which was statistically insignificant (P = 0.642). The mean motor onset time in MG group was 13.35 ± 2.62 min and13.54 ± 2.60 min in NS group, which again was statistically insignificant (P = 0.763). The duration of sensory block for MG group was 424.12 ± 53.43 min and 226.57 ± 27.22 min for NS group. This was statistically significant (P ≤ 0.001). The duration of motor block for MG group was 361.62 ± 43.04 min and 208.29 ± 27.38 min for NS group. This was statistically significant (P ≤ 0.001). The duration of analgesia for MG group was 436.18 ± 53.88 min and 234.00 ± 30.31 min for NS group. This too was statistically significant (P ≤ 0.001). There were no significant differences between the study groups with respect to changes in heart rate, systolic blood pressure, diastolic blood pressure, mean arterial blood pressure, and saturation perioperatively. There was no incidence of nausea and vomiting in both the groups. Conclusion: Magnesium sulfate infusion improves the quality of epidural anesthesia, postoperative analgesia requirements, and nausea and vomiting in patients undergoing infra-umbilical surgery.

Keywords

• analgesia
• epidural anesthesia
• infra-umbilical surgeries
• magnesium sulfate