Intrathecal magnesium sulphate as an adjuvant to bupivacaine for infraumbilical surgeries: An updated systematic review and meta-analysis

Background and Aims: Intrathecal anaesthesia is widely used for infraumbilical surgeries due to its effectiveness in providing pain relief during and after the operation. Adding magnesium sulphate (MgSO 4 ) to intrathecal local anaesthetics can prolong analgesia, reduce postoperative analgesic requirements and improve the management of shivering perioperatively. This review aims to investigate the use of intrathecal adjuvant MgSO4 for anaesthesia in infraumbilical surgeries. Methods: We performed a meta-analysis (PROSPERO ID: CRD42023432378) of trials, which included patients who underwent a variety of surgical procedures under spinal anaesthesia with intrathecal MgSO 4 as an adjuvant to spinal local anaesthetics. The analysed outcomes included sensory and motor effects and adverse effects. We presented dichotomous outcomes as risk ratios with 95% confidence intervals (CI), while continuous outcomes were measured as mean differences (MDs) with 95% CI. We considered the results significant if the P value was < 0.05. Results: Thirty-two studies (2379 patients) were included. Adding intrathecal MgSO 4 to bupivacaine significantly prolonged the time for regression of two segments from the maximum height (MD: 27.18 min; 95% CI: 12.56, 41.79; P = 0.0003), delayed the onset of sensory block to T10 (MD: 1.93 min; 95% CI: 1.10, 2.77; P < 0.0001), prolonged the duration of motor block (Bromage score = 0) (MD: 15.13 min; 95% CI: 4.59, 25.66; P = 0.005) and extended time for first rescue analgesia (MD: 43.80 min; 95% CI: 26.47, 61.14; P < 0.00001). No significant effect for MgSO 4 on side effects was observed. Conclusion: Our review underscores intrathecal MgSO 4 ’s benefits in prolonging block duration and improving pain management, but highlights significant heterogeneity, limiting the strength of these findings.