Erector spinae plane block for opioid sparing in children undergoing laparoscopic appendectomy: a randomized controlled trial

Background Despite being a minimally invasive procedure, laparoscopic appendectomy (LA) frequently induces substantial postoperative pain in children. While erector spinae plane block (ESPB) has demonstrated efficacy for postoperative analgesia in pediatric open abdominal surgery, its analgesic benefits and safety profile in laparoscopic procedures remain unestablished. Purpose To evaluate the opioid-sparing effects, analgesic efficacy, and safety of ESPB in children undergoing LA. Design A single-center, double-blind, randomized, superiority trial. Methods Children aged 6–12 years with American Society of Anesthesiologists (ASA) physical status I–II scheduled for LA at Anhui Provincial Children's Hospital were enrolled. Participants were randomly allocated 1:1 using a computer-generated sequence to receive either bilateral ultrasound-guided ESPB at T8 (0.25% ropivacaine, 0.5 mL/kg per side) after tracheal intubation (ESPB group) or no block (Control group). Both groups received standardized multimodal analgesia comprising hydromorphone-based patient-controlled intravenous analgesia (PCIA) and scheduled acetaminophen. The primary outcome was 0–24 h cumulative hydromorphone consumption; secondary outcomes included pain scores, PCIA parameters, rescue analgesia requirements, recovery milestones, parental satisfaction, and adverse events. Results Of the 80 children randomized (40 per group), 75 completed follow-up and were analyzed (ESPB, n = 37; control, n = 38). The ESPB group exhibited significantly lower 24 h hydromorphone consumption (32.8 ± 10.1 vs. 72.9 ± 14.5 μg/kg; mean difference: −40.1 μg/kg; P < 0.001), representing a 55% reduction compared with the Control group. Secondary outcomes favoring ESPB included lower pain scores during the early postoperative period (PACU to 6 h; P < 0.05), prolonged time to first PCIA demand (201.0 vs. 58.5 min; P < 0.001), fewer total PCIA presses (10 vs. 17; P < 0.001) and effective presses (9 vs. 17; P < 0.001) within 0–24 h, reduced rescue analgesia requirements (2.7% vs. 21.1%; P = 0.028), and higher parental satisfaction scores (8 vs. 7 points; P = 0.001). No serious block-related complications occurred. Conclusions In children undergoing LA, a single-injection bilateral ultrasound-guided ESPB at T8 provides significant opioid-sparing effects and alleviates acute postoperative pain during the first 24 h without increasing adverse event rates, supporting its incorporation as a component of multimodal analgesia for postoperative pain management in this population. Clinical Trial Registration : https://www.chictr.org.cn , identifier ChiCTR2500108148, Date of Registration: August 26, 2025.