Analgesic Effects of Regional Analgesic Techniques in Pediatric Inguinal Surgeries: A Systematic Review and Network Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: Various regional analgesic techniques have been used in pediatric inguinal surgery to facilitate postoperative recovery. However, each technique's relative performance was undetermined owing to the lack of quantitative analysis. METHODS: We systematically searched MEDLINE, Cochrane Library, EMBASE, and Web of Science for randomized controlled trials that compared regional analgesia in pediatric inguinal surgeries. After critical study screening and selection, a random-effects network meta-analysis was performed. The primary outcome was the time to the first rescue analgesic after surgery, and the secondary outcomes were the number of patients requiring rescue analgesics after surgery, postoperative pain scores, incidence of postoperative nausea and vomiting, and other adverse events. RESULTS: This network meta-analysis included 69 randomized controlled trials (4636 patients) that compared 10 regional analgesic techniques. Our study revealed that the quadratus lumborum and transversus abdominis plane blocks had the longest time to the first rescue analgesic after pediatric inguinal surgeries, by 7.7 hours (95% confidence interval [CI], 5.0-10.3) and 6.0 hours (95% CI, 3.9-8.2) when compared with the control group, respectively. In the subgroup involving only inguinal hernia repair, the quadratus lumborum block significantly prolonged the time to the first rescue analgesic than all other regional analgesics. In contrast, in the subgroup involving orchidopexies, only the caudal block significantly prolonged the time to the first rescue analgesic when compared with the control group (4.1 hours; 95% CI, 0.7-7.5). Wound infiltration and landmark-based ilioinguinal-iliohypogastric block had relatively poor analgesic effects than other regional analgesics. No serious adverse effects related to the regional analgesic techniques were reported in any of the included studies. CONCLUSIONS: The quadratus lumborum and transversus abdominis plane blocks had the longest time to the first rescue analgesic and the least rescue analgesic requirement for pediatric inguinal surgeries. Specifically, the quadratus lumborum block had the longest analgesic duration in inguinal hernia repair, and the caudal block was found to be the only regional analgesia that extended the time to the first rescue analgesic in pediatric orchidopexy. Most included randomized controlled trials had some concern or a high risk of bias, and future studies should focus on providing high-quality evidence to further clarify the analgesic effects of regional analgesia for pediatric inguinal surgeries.