Background: Transversus abdominis plane block (TAPB) has emerged as a safe and effective regional anaesthesia technique for providing postoperative analgesia following lower abdominal surgeries. Complications associated with ultrasound guided TAPB are rare and pose a lower overall risk to the patient receiving TAPB versus caudal block (CEB), which is considered as gold standard for paediatric lower abdominal surgeries. Our study hypothesis was that TAPB would initially be equivalent to caudal block in providing postoperative pain control but would also show improved pain relief beyond the anticipated caudal duration.

Methods: This was a randomised controlled trial involving 80 children, 1-7yrs old, randomly allocated into one of the two equal groups; TAPB group (T-group) and CEB group (C group). Children underwent lower abdominal surgeries. All children received general anaesthesia using ketamine 2mg/kg and 1% sevoflurane. Group T received  0.5ml/kg of 0.25% bupivacine and group C received 0.75ml/kg of 0.25% bupivacaine under ultrasound guidance. Primary outcome measures were pain scores and duration of analgesia. Pain scores were assessed using Wong Baker FACES scale and FLACC scale. Secondary outcome measured were time taken for instilling the block, hemodynamics, and parent satisfaction and any other adverse events.

Results: TAPB patients had significantly longer duration of analgesia compared to CEB patients (p<0.001). Regarding pain scores, after 6hrs, there was a significant difference in the pain scores (p=0.02) between two groups with group T having low pain scores. There was no statistically significant difference in the time taken for instilling the block  (p=0.139). There was statistically significant increase in HR and MAP intra-operatively in group T patients (p<0.001) at 10 and 15min post block time. There was no statistically significant difference between two groups regarding parent’s satisfaction. (p=0.136).Thus pain scores were significantly lower in group T and duration of analgesia also lasted longer. None of our patients had any complications postoperatively nor did we have any exclusions.

Conclusion: Both CEB and TAPB give adequate analgesia during the early Post-operative period. However, TAPB results in prolonged analgesia beyond the anticipated CEB duration. Considering the safety profile of TAPB and avoiding the narcotics related side effects, this should be considered a preferred regional technique over CEB for lower abdominal surgeries whenever possible.