Regional analgesia techniques as adjuncts to general anesthesia in pediatric cardiac surgery: an updated systematic review and meta-analysis of randomized controlled trials

BACKGROUND: Regional analgesia (RA) is increasingly used in pediatric cardiac surgery, but evidence supporting its benefit remains fragmented. This systematic review and meta-analysis aimed to determine the "class effect" of RA. METHODS: A systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted. Data sources included PubMed, Embase, Cochrane Library, and Web of Science, searched up to July 10, 2025. We included RCTs of pediatric patients undergoing cardiac surgery that compared any RA technique (neuraxial, peripheral nerve blocks, or local infiltration) against general anesthesia with systemic analgesia alone. RESULTS: 31 RCTs (n=2245) were included. Adjunctive RA was associated with significant reductions in intraoperative fentanyl (MD -2.50 µg·kg⁻¹; 95% CI -3.84 to -1.15; 95% PI -9.51 to 4.52; I²=97%), 24-hour intravenous morphine (MD -0.33 mg·kg⁻¹; 95% CI -0.55 to -0.11; 95% PI -1.17 to 0.51; I²=96%), and improved recovery. Benefits included shorter time to tracheal extubation (MD -1.72 hours; 95% CI -2.93 to -0.52; 95% PI -7.78 to 4.34; I²=99%), reduced ICU stay (MD -0.25 days; 95% CI -0.34 to -0.16; 95% PI -0.61 to 0.11; I²=93%), and prolonged time to first analgesia (MD 2.95 hours; 95% CI 1.86 to 4.04; 95% PI -1.42 to 7.31; I²=97%). Subgroup analyses showed outcome-specific, inconsistent effects. CONCLUSION: There is very low to low certainty of evidence that adjunctive RA is associated with reduced opioid exposure and improved recovery in pediatric cardiac surgery. Substantial heterogeneity and imprecision markedly reduce confidence in the estimated effects, which should therefore be interpreted cautiously. REGISTRATION: PROSPERO CRD420251073543.