Quadratus Lumborum Block is an Effective Postoperative Analgesic Technique in Pediatric Patients Undergoing Lower Abdominal Surgery: A Meta-Analysis

Background: Quadratus lumborum (QL) block has shown promising analgesic efficacy in the adult population in previous meta-analyses. However, the response of the pediatric group to pain stimulation is stronger than that in the adult population, and the management of pediatric pain is constrained by limited available analgesia agents. All data analyzed during this study are collected from published articles. Objective: The purpose of our systematic review was to evaluate whether QL block is also an effective postoperative analgesic technique, compared to other analgesic skills in pediatric patients undergoing lower abdominal surgery. Study Design: A meta-analysis. Methods: We identified randomized controlled trials (RCTs) from PubMed, Embase, the Cochrane Library, Web of Science, and Science Direct to compare QL block with other analgesic methods for relief of postoperative pain in pediatric patients undergoing lower abdominal surgeries under general anesthesia. The primary outcome was the rate of postoperative rescue analgesia; secondary outcomes include: pain scores at 30 minutes and 1, 2, 4, 6, 12, and 24 hours postoperatively, patient satisfaction, and block related complications. Results: A total of 7 studies with 346 patients were included. QL block showed a significant reduction in the rate of postoperative rescue analgesia in the first 24 hours (RR = 0.41; 95% CI = 0.28 to 0.59; P < 0.001) compared to other analgesic techniques, without significant heterogeneity among the articles (I-2 = 49%, P = 0.08). Compared with other analgesic methods, QL block significantly reduced the pain scores at 2 hours (Std.MD = -0.76; 95% CI = -1.16 to -0.35; P < 0.001) (I-2 < 0.001%, P = 0.41), 4 hours (Std.MD = -0.34; 95% CI = -0.67 to -0.01; P = 0.04) (I-2 < 0.001%, P = 0.53) and 12 hours postoperatively (Std.MD = -0.95; 95% CI = -1.44 to -0.47; P < 0.001) (I-2 = 27%, P = 0.24). No significant differences were found between techniques at 30 minutes and 1, 6, or 24 hours postoperatively (P > 0.05). There was no statistically significant change in patient satisfaction (Std.MD = 0.49; 95% CI = -0.32 to 1.29; P = 0.24) or side effects (RD = -0.02; 95% CI = -0.06 to 0.02; P = 0.31) with QL block. Limitations: The major limitation of this meta-analysis is the relatively few RCTs and limited results included. Similarly, the differences in block approaches among the control groups (TAP, ESP, caudal block, opioid-based analgesia), drug types and concentrations, and multimodal analgesia programs led to considerable heterogeneity. Furthermore, some relevant outcomes were not investigated. Conclusion: Our systematic review and meta-analysis suggests QL block use for the pediatric population undergoing lower abdominal surgery, based on the current limited research evidence, as this method was an effective postoperative analgesic technique.