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

Abstract

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 µg/kg dexmedetomidine while the other group received a TAP block with 0.25% bupivacaine 0.5 ml/kg with 1 µg/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.

Considerations for assessing optimal regional anaesthesia and analgesia in paediatric surgical patients

“…In children requiring single-shot regional analgesia for lower abdominal surgery, it appears that TAP blocks may be marginally preferable due to the need for less rescue analgesia in the early postoperative period, and a longer duration of analgesia than when compared to a caudal block. 6 However, the limitation to this conclusion, may be related to a caudal dose which could have been inadequate in some patients.…”

“…Reddy et al used a total dose of 1.25 mg/kg of bupivacaine for the TAP blocks. 6 When conducting randomised trials comparing IFPB with other blocks, a control group with intravenous infusion of local anaesthetic could be an important arm to add to a trial to address this controversy.…”

“…Although potentially challenging, prospective randomised trials can be performed in children, as shown by Reddy et al 6 Large, prospective, randomised trials are needed to provide good evidence for the analgesic efficacy of the newer regional anaesthesia techniques. It is important that these trials use comparable doses of local anaesthetic and adjuvants, and ensure that they use well described standard techniques.…”

“…In this issue of the journal, Reddy et al present the results of a prospective randomised trial comparing ultrasound-guided transversus abdominis plane (TAP) block and ultrasound-guided caudal block for postoperative pain in children undergoing lower abdominal surgeries. 6 We welcome well-conducted randomised trials which add to the body of evidence supporting the use of appropriate regional anaesthesia techniques for perioperative pain relief in children.…”

“…7,8 Two of the controversies addressed were the use of adjuvants in PRA and dosing of local anaesthetics in PRA. 7 Reddy et al 6 provided single-shot techniques, with a standard dose across groups, and the use of a standard dose adjuvant of dexmedetomidine. Any single-shot block is limited by the duration of that block.…”