Opioid-free general anesthesia in breast surgery: a meta-analysis of randomized trials

Background: Opioid-free general anesthesia (OFGA) is increasingly adopted in clinical settings owing to its potential to reduce opioid-associated adverse events. This systematic review and meta-analysis aimed to evaluate the efficacy of OFGA versus opioid-based general anesthesia (OBGA) in breast surgery patients. Methods: We systematically searched Cochrane Library, PubMed, Embase, and Web of Science for randomized controlled trials (RCTs) comparing OFGA with OBGA in breast surgery. The primary focus was postoperative nausea and vomiting (PONV) incidence. Data were analyzed using Review Manager 5.3 and Stata V.12.0. Evidence certainty was evaluated using Grading of Recommendations Assessment, Development and Evaluation (GRADE) criteria. Results: A total of 6 RCTs involving 493 patients were included in this analysis. Compared with the OBGA group, the OFGA group showed a significant reduction in PONV incidence (risk ratio = 0.17, 95% confidence interval (0.09, 0.31); p ≤ 0.05, I2 = 0%), and shorter extubation time. Additionally, the OFGA technique was associated with more stable intraoperative hemodynamics and a lower postoperative neutrophil-lymphocyte ratio. Conclusions: Current evidence suggests that OFGA may be a promising alternative for patients undergoing breast surgery. However, higher-powered trials are required to confirm these outcomes. The PROSPERO Registration: International Prospective Register of Systematic Reviews (PROSPERO) registration number: CRD42024517527.