Ultrasound-guided transversus abdominis plane block versus caudal block for postoperative pain relief in infants and children undergoing surgical pyeloplasty

Background Caudal block is the most frequently used regional anesthetic technique for pediatric analgesia, with the disadvantage of limited duration of action. Transversus abdominis plane (TAP) block has been reported to provide effective analgesia after lower abdominal surgery, but there are few data comparing caudal block with ultrasound-guided TAP block in pediatric patients undergoing surgical pyeloplasty. Patients and methods Thirty-nine patients (6 months to 6 years) scheduled for elective surgical pyeloplasty were divided into two groups in a double-blinded randomized manner. After sevoflurane in oxygen anesthesia, patients were assigned to one of the two groups: group A (caudal; n = 19 patients) received a single caudal dose of isobaric bupivacaine 0.25% (1.25 ml/kg) and group B (TAP block; n = 20 patients) received isobaric bupivacaine 0.25% (0.3 ml/kg). The primary outcomes were the time to first analgesia in minutes and the analgesic doses (oral acetaminophen and rectal diclofenac) required during the first 24 h postoperatively. The secondary outcome measures included FLACC pain scale score and intraoperative hemodynamic variables. Results Group B had a significantly longer time to first analgesia (602, 705, 748 vs. 250, 280, 365 min) and required significantly lower doses of acetaminophen (301.9 ± 161.26 vs. 635.05 ± 205.42) and rectal diclofenac (0, 0, 0 vs. 0, 0, 12.5 mg) than group A. FLACC pain scale score was significantly lower in group B than in group A (P 0.05) at 2, 4, 6, 8, 10, 12, 16, 18, 20, and 24 h postoperatively. There was no significant difference between both groups with respect to intraoperative hemodynamic variables. Conclusion Unilateral TAP block provided superior analgesia compared with single caudal block injection in the first 24 postoperative hours after surgical pyeloplasty in infants and children aged 6 months to 6 years.