Meta-analysis finds opioid-free anesthesia improves postoperative recovery versus opioid anesthesia

PURPOSE: Opioids have long been an integral component of pain management in general anesthesia protocols. However, recent studies have increasingly supported the use of opioid-free anesthesia. This meta-analysis aimed to assess the effects of opioid anesthesia compared with opioid-free anesthesia on postoperative recovery. DESIGN: A systematic review and meta-analysis of randomized controlled trials, adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. METHODS: We systematically searched Embase, PubMed, and the Cochrane Central Register of Controlled Trials up to June 18, 2023. Studies were included if they compared opioid-free anesthesia to opioid anesthesia and reported the quality of postoperative recovery. Meta-analyses primarily utilized a random-effects model. FINDINGS: In total, 13 randomized controlled trials, comprising 1,733 patients, were included in this analysis. The results indicated that opioid-free anesthesia improved the quality of postoperative recovery, with standardized mean difference of 0.46 (95% confidence intervals [CI]: 0.29 to 0.63, I = 56%, P < .001) for quality of recovery. These benefits were evident in all types of surgeries. However, the clinical significance of these differences is limited. Furthermore, the opioid-free anesthesia group required less postoperative rescue analgesia and had a lower incidence of postoperative nausea and vomiting, with risk ratios of 0.54 (95% CI: 0.37 to 0.78), I = 0%, P less than .001, and 0.39 (95% CI: 0.27 to 0.57), I = 0%, P less than .001, respectively. CONCLUSIONS: Combined analyses showed that opioid anesthesia was not superior to opioid-free anesthesia in terms of the quality of recovery, and the risk of nausea and vomiting was higher.