Effect of Intraoperative Ondansetron on Preventing Postoperative Nausea and Vomiting in Orthognathic Surgery

<p>  The incidence of postoperative nausea and vomiting (PONV) in patients undergoing orthognathic surgery is high. Moreover, PONV persist despite using total intravenous anesthesia (TIVA) featuring propofol. We investigated the incidence of PONV after orthognathic surgery conducted under TIVA using propofol along with ondansetron, compared to that without using ondansetron. Patients with ASA physical status of Ⅰ or Ⅱ, who underwent orthognathic surgery under TIVA using propofol between April 2020 and March 2023, were enrolled. Patients who underwent awake intubation or postoperative ventilatory management, who were not administered betamethasone intraoperatively, were excluded. The following data were extracted from the electronic medical record : age, sex, body mass index, operation time, blood loss, awake intubation, dose of fentanyl and ondansetron, history of smoking and PONV, and postoperative headache. Postoperative nausea, vomiting, and use of antiemetics within 24 hours after surgery were also extracted. The primary outcome was that PONV is defined as the presence of at least one of these parameters. We divided patients into ondansetron and control groups. We compared the incidence of PONV between groups using Pearson’s chi-square test after propensity-score matching. Among the 291 eligible patients, 78 patients were included in each group after propensity-score matching. Baseline patient characteristics were acceptably balanced between the groups. The incidence of PONV in the ondansetron group was significantly lower than that in the control group (21% vs. 36%, p＝0.033), whereas postoperative headache was comparable between the groups. Ondansetron effectively reduces PONV in patients undergoing orthognathic surgery under TIVA without an increase in headache.</p>