Evaluation of analgesic efficacy of magnesium sulfate as an adjuvant to caudal bupivacaine in pediatric infraumbilical surgeries – A prospective randomized double-blind study

Background and Aims: Caudal block provides good perioperative analgesia for pediatric infraumbilical surgeries but has a short duration of action after a single injection. To overcome this limitation, we evaluated the effect of magnesium sulfate added to caudal bupivacaine on postoperative analgesia in pediatric patients undergoing infraumbilical surgeries. Materials and Methods: In this prospective randomized double-blind comparative study, 60 American Society of Anesthesiologists Grade I, II children aged 1–5 years, of either gender, undergoing infraumbilical elective surgeries were randomly divided into 2 Groups (Group M [Magnesium sulfate] and Group C [control]) and received caudal block with magnesium sulfate 50 mg (upto 1 ml with saline) and 1 ml saline, respectively, added to 1 ml/kg of 0.25% bupivacaine. Hemodynamic parameters were recorded at predefined time intervals. Postoperative pain by Face, Legs, Activity, Cry and Consolability (FLACC) scale and level of sedation by Ramsay Sedation Score was assessed postoperatively. Duration of analgesia and number of rescue analgesic doses received in 24 h were recorded. Quantitative and qualitative variables were analyzed using Mann–Whitney U test, Chi-Square test, and Kruskal–Wallis test where deemed appropriate. P ≤ 0.05 was considered statistically significant. Results: The mean duration of analgesia was significantly higher in Group M with reduced requirement of rescue analgesic doses. FLACC scores were higher in control Group C at all time intervals. Patients in the magnesium group were sedated for a longer period. Both groups had comparable hemodynamic parameters throughout the study. Conclusion: Magnesium sulfate as an adjuvant to bupivacaine in caudal block prolongs the duration of analgesia with a reduction of postoperative rescue analgesic requirement in pediatric patients.