Background and Objectives Truncal blocks have a place within multimodal analgesia techniques in abdominal surgery. The quadratus lumborum block is a new abdominal truncal block used for somatic analgesia of both the upper and lower abdomen. In this prospective, double-blind, randomized study, we aimed to compare quadratus lumborum block and transversus abdominis plane block in pediatric patients undergoing lower abdominal surgery.

Methods Fifty-three children undergoing unilateral inguinal hernia repair or orchiopexy surgery were randomized into 2 groups: transversus abdominis plane block and quadratus lumborum block. All blocks were performed under general anesthesia before surgery. Pain levels were assessed using an FLACC (Face, Legs, Activity, Cry, Consolability) scale.

Results The study included 50 patients, after excluding 3 patients who were not eligible. The number of patients who required analgesia in the first 24 hours postoperatively was significantly lower in the quadratus lumborum block group (P < 0.05). In the quadratus lumborum block group, the postoperative 30-minute and 1-, 2-, 4-, 6-, 12-, and 24-hour FLACC scores were lower compared with those of the transversus abdominis plane block group (P < 0.05). Parent satisfaction scores were higher in the quadratus lumborum block group (P < 0.05).

Conclusions The results of this study showed that in pediatric patients undergoing unilateral inguinal hernia repair or orchiopexy the quadratus lumborum block provided longer and more effective postoperative analgesia compared with the transversus abdominis plane block.

Clinical Trials Registration: The trial was registered prospectively at clinicaltrials.gov (NCT02715999).