Efficacy and Safety of Intrathecal Magnesium Sulphate as an Adjuvant to Hyperbaric Bupivacaine Versus Isobaric Levobupivacaine in Caesarean Deliveries: A Prospective, Randomized, Double-Blind, Controlled Trial.

Background Hyperbaric bupivacaine (HB), commonly used in caesarean sections (CS), may cause cardiotoxicity and high sympathetic blocks. Isobaric levobupivacaine (IL) provides effective sensory block with fewer hemodynamic changes and less toxicity. Adding magnesium sulphate (MS) enhances spinal anaesthesia. This study compared the efficacy and safety of intrathecal 0.5% IL-MS combination with 0.5% HB-MS combination in patients undergoing CS. Methods This prospective, randomized, double-blind, parallel-group study involved 74 parturients undergoing CS. The patients were randomly divided into two groups: IL-MS group (n=37, 0.5% IL and 75mg MS) and HB-MS group (n=37, 0.5% HB and 75mg MS). The time to the first request for analgesia was the primary outcome measure. The secondary outcome measures were time to achieve sensory and motor block, time to sensory and motor recovery, and adverse events. Results The IL-MS group had a significantly longer time to first rescue analgesia (487 min) compared to the HB-MS group (409 min, p < 0.05). Early sensory block (4 min vs. 5 min, p < 0.01) and motor block onset (5 min vs. 6 min, p < 0.01) were achieved in the IL-MS group compared to HB-MS. Earlier sensory (278 min vs 306 min, p < 0.01) and motor recovery (243 min vs. 268 min, p < 0.01) in the IL-MS group than the HB-MS group were achieved. Adverse events were fewer in the IL-MS group, including no bradycardia cases compared to the HB-MS group. Conclusion Intrathecal IL-MS is a useful alternative to HB-MS for patients undergoing CS with longer duration of analgesia and better hemodynamic stability.