Comparative study between an ultrasound-guided transversus abdominis plane block and an ultrasound-guided caudal block for postoperative analgesia in children undergoing lower abdominal surgeries - a prospective randomised study

Background: Ultrasound imaging techniques have gained great popularity in anaesthesia during the last decade. We aimed to compare an ultrasound-guided transversus abdominis plane (TAP) block and an ultrasound-guided caudal block for postoperative analgesia in children undergoing lower abdominal surgeries. Methods: This study randomly allocated 62 children to two groups of 31 children each. One group received a caudal block with 0.25% bupivacaine 0.5 ml/kg with 1 mu g/kg dexmedetomidine while the other group received a TAP block with 0.25% bupivacaine 0.5 ml/kg with 1 mu g/kg dexmedetomidine. The parameters that were compared were the duration of postoperative analgesia, cumulative dose of rescue analgesic consumed, FLACC pain scores postoperatively, intraoperative and postoperative haemodynamic changes and incidence of side effects. Results: The duration of analgesia was comparable between the two groups, with 6.61 +/- 0.76 hours for the caudal block group and 6.65 +/- 0.915 hours for the TAP block group. However, the total amount of cumulative rescue analgesic consumed was significantly higher in the caudal block group (375.8 +/- 120.5) compared to the TAP block group (314.5 +/- 127.7). The pain scores in 0-6 hours postoperatively were higher in the TAP block group, whereas the caudal block group had higher pain scores 6-24 hours postoperatively with steady rescue analgesic consumption at 8, 12, 16 and 20 hours. Patient-parent satisfaction was better in the TAP block group (7.39 +/- 0.76) compared to the caudal block group (6.48 +/- 0.811). Conclusion: The TAP block provided superior analgesia compared to the caudal block, as demonstrated by a statistically significant decrease in the required cumulative rescue analgesic and lower pain scores 6-24 hours postoperatively.