Effect of Opioid-Sparing Anesthesia on Postoperative Nausea and Vomiting After Breast Surgery: A Single-Center Randomized Controlled Trial

Background/Objectives: Postoperative nausea and vomiting (PONV) remain frequent after breast surgery despite prophylaxis. This single-center, parallel-group randomized controlled trial evaluated whether intraoperative opioid-sparing anesthesia using dexmedetomidine and lidocaine reduced 48 h PONV compared with opioid-based anesthesia. Methods: Adult women undergoing elective breast surgery were randomized 1:1 to opioid-sparing anesthesia with dexmedetomidine and lidocaine or conventional opioid-based anesthesia with remifentanil. Participants and postoperative outcome assessors were blinded to group allocation; attending anesthesiologists were not blinded. All patients received standardized sevoflurane anesthesia, dexamethasone, ramosetron, quantitative neuromuscular monitoring, and postoperative fentanyl patient-controlled analgesia. The primary outcome was PONV within 48 h after surgery. Results: Among 68 randomized patients, 67 were analyzed (opioid-sparing group, n = 33; control group, n = 34). PONV within 48 h occurred in 8 patients (24.2%) in the opioid-sparing group and 28 patients (82.4%) in the control group (risk ratio, 0.29; 95% confidence interval, 0.16–0.55; p < 0.001; absolute risk reduction, 58.1%; number needed to treat, 1.7). Rescue antiemetic use was lower in the opioid-sparing group in the postanesthesia care unit and at 1 h postoperatively. Pain scores and cumulative opioid consumption were comparable. No Clavien–Dindo grade III or higher complications occurred. Conclusions: Intraoperative opioid-sparing anesthesia was associated with lower 48 h PONV after breast surgery without apparent compromise in analgesia. These single-center findings, from a trial registered after enrollment of one participant, require confirmation in larger prospectively registered multicenter trials. Trial Registration: Clinical Research Information Service (CRIS), KCT0009829. Registered on 10 October 2024.