Efficacy of esketamine in reducing nausea and vomiting after anesthesia: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Postoperative nausea and vomiting (PONV) are significant perioperative challenges. This study evaluated the efficacy of perioperative esketamine in preventing PONV. MATERIALS AND METHODS: We systematically searched Embase, PubMed, Web of Science, and the Cochrane Library from inception to August 2025 for randomized controlled trials investigating the effect of perioperative esketamine on PONV. The primary outcome was PONV incidence. Secondary outcomes included time to first flatus, postoperative pain degree, anxiety scores, agitation, anesthesia recovery time, and post-anesthesia care unit (PACU) stay duration. Data were analyzed using RevMan 5.4 and STATA 15.0 software. Sensitivity and subgroup analyses were performed to assess result stability and explore potential sources of heterogeneity. RESULTS: Thirty-eight randomized trials (3,425 patients) were included. Esketamine reduced the risk of nausea (RR=0.69, 95% CI: 0.53-0.90) and vomiting (RR=0.75, 95% CI: 0.57-0.98), shortened time to first flatus (SMD=-0.81, 95% CI: -1.48 to -0.15), and decreased rescue analgesic needs within 2 days (SMD=0.32, 95% CI: 0.2-0.5). However, it prolonged anesthesia recovery time (SMD=0.97, 95% CI: 0.28-1.67) and PACU stay (SMD=0.76, 95% CI: 0.27-1.26). CONCLUSIONS: Perioperative esketamine may reduce PONV and aid gastrointestinal recovery, but its potential to delay anesthesia recovery and PACU discharge requires consideration. Further studies are needed to clarify its risk-benefit profile. DATE OF FIRST SUBMISSION TO PROSPERO: 10 March 2024. DATE OF THE START OF STUDY SCREENING AGAINST ELIGIBILITY CRITERIA: 21 March 2024.