A Comparative Study of Intravenous Magnesium Sulphate Versus Intrathecal Magnesium Sulphate in 0.5% Hyperbaric Bupivacaine Spinal Anaesthesia for Elective Infraumbilical Surgery

BACKGROUND In this study, we wanted to compare the characteristics of subarachnoid block when intrathecal versus intravenous magnesium sulphate was used with 0.5 % hyperbaric bupivacaine spinal anaesthesia in elective infraumbilical surgery. METHODS This was a hospital based prospective randomized clinical parallel arm study double-blinded (patient and observer blinded) single hospital study conducted among 100 patients who presented with elective infraumbilical surgery under spinal anaesthesia to the Department of Anesthesiology and Critical Care, Gauhati Medical College and Hospital, Guwahati, from 1st June 2021 to 31st May 2022 after obtaining clearance from the institutional ethics committee and written informed consent from the study participants. RESULTS The onset of sensory block, and comparison of duration of analgesia with respect to time to first analgesic request was found to be statistically significant. While comparing, duration of analgesia was significantly prolonged in the intravenous group. Magnesium administered intravenously or intrathecally was not linked to any harmful side effects. CONCLUSIONS Infraumbilical procedures that use intravenous magnesium sulphate as an adjuvant to 0.5% hyperbaric bupivacaine spinal anaesthetic extend the time that post-operative analgesia lasts. Intrathecal co-administration of Magnesium sulphate with 0.5% hyperbaric bupicavaine delays the onset of sensory block compared to intravenous MgSO4.