Background and aims An ilioinguinal/iliohypogastric nerve block (II/IHB) is commonly performed to control post-herniotomy pain. the ultrasound-guided (USG) quadratus lumborum block (QLB) also provides effective analgesia for lower abdominal surgery. This randomised, assessor-blinded study aimed to compare analgesic effect of the USG-QLB and USG-II/IHB after paediatric unilateral inguinal hernia surgery.

Methods After obtaining ethics committee approval (Maharaj Nakorn Chiang Mai Hospital), a total of 40 paediatric patients were randomly allocated to receive either a USG-QLB with 0.25% bupivacaine 0.5 ml/kg or a USG-II/IHB with 0.25% bupivacaine 0.2 ml/kg after induction of general anaesthesia. the primary outcomes were the 24-hour postoperative analgesic requirements and Children’s Hospital of Eastern Ontario Pain Scale (CHEOPS) at 2, 6, 12, and 24 hours after surgery. the secondary outcomes were block performance time, success rate, block-related complications and parental satisfaction.

Results Preliminarily, 25 of 40 patients were recruited. the success rate was 100% for both groups. During the first 24 hours, 3 (23.1%) and 6 (50.0%) children in the QLB and II/IHB groups received oral acetaminophen (P = 0.226). Compared to the QLB group, the median [interquartile range (IQR)] acetaminophen dosage was higher (4.5 [0–12.3] vs 0 [0–0] mg/kg; P = 0.100) and the median [IQR] time to the first acetaminophen requirement was shorter (5.3 [3.8–6.3] vs 10 [3.8–11.5] hour; P = 0.134) in the II/IHB group. the CHEOPS, block performance time and parental satisfaction were similar. Only one patient in the II/IHB group had a vascular puncture.

Conclusions The USG-QLB and USG-II/IHB provide comparable analgesia following paediatric open inguinal herniotomy.