Ultrasound-guided sacral multifidus plane block versus caudal epidural block for postoperative analgesia in pediatric hypospadias surgery: A randomized double-blind controlled trial

INTRODUCTION: Hypospadias repair is associated with moderate to severe postoperative pain in children. Caudal epidural block is traditionally considered the standard regional anesthetic technique for sub-umbilical pediatric surgeries; however, its duration of analgesia and potential adverse effects may be limited. The sacral multifidus plane block (SMPB) is a novel ultrasound-guided fascial plane technique that may provide prolonged analgesia with fewer complications. The aim of this study is to compare the analgesic efficacy and safety of ultrasound-guided sacral multifidus plane block versus caudal epidural block in children undergoing hypospadias repair. MATERIALS AND METHODS: This prospective, randomized, double-blind controlled trial included 30 children aged 1-5 years (ASA I-II) scheduled for hypospadias repair. Patients were randomly allocated to receive either SMPB (n = 15) or caudal block (n = 15), using 1 mL/kg of 0.25% bupivacaine. The primary outcome was time to first rescue analgesia. Secondary outcomes included postoperative FLACC pain scores, total rescue analgesic consumption, intraoperative fentanyl requirements, hemodynamic variables, and block-related complications. Pain was assessed for 24 hours postoperatively. RESULTS: Demographic and intraoperative characteristics were comparable between groups. Time to first rescue analgesia was significantly longer in the SMPB group compared with the caudal group (14.8 ± 3.6 vs 9.3 ± 4.2 hours, p = 0.004). FLACC scores were significantly lower in the SMPB group at 6 and 12 hours postoperatively (p = 0.019 and p = 0.001, respectively). Total diclofenac consumption was lower in the SMPB group (0.40 ± 0.20 mg/kg vs 0.70 ± 0.24 mg/kg, p = 0.010). Intraoperative fentanyl requirements and hemodynamic parameters were similar. No major complications were observed. CONCLUSION: Ultrasound-guided sacral multifidus plane block provides longer-lasting postoperative analgesia and reduces rescue analgesic requirements compared with caudal epidural block in pediatric hypospadias surgery, with a comparable safety profile. SMPB may represent a reliable alternative to caudal block for postoperative pain management in this population.