The effect of combining dexamethasone with ondansetron for nausea and vomiting associated with fentanyl‐based intravenous patient‐controlled analgesia*

Summary We investigated whether combined dexamethasone and ondansetron is more effective than ondansetron alone in preventing postoperative nausea and vomiting in patients with fentanyl‐based intravenous patient‐controlled analgesia. One hundred and thirty patients undergoing video‐assisted thoracoscopic surgery were assigned to either an ondansetron group or a dexamethasone and ondansetron group. In all patients, ondansetron 4 mg was administered at the end of surgery and 12 mg was added to the patient‐controlled analgesia solution. The dexamethasone and ondansetron group received dexamethasone 8 mg at the induction of anaesthesia. The overall incidence of nausea and vomiting during the first 48 h postoperatively did not differ between groups (34/61 (56%) vs 28/62 (45%) in the ondansetron group and dexamethasone and ondansetron groups, respectively). The incidence of severe nausea and vomiting (≥ 7 nausea on an 11‐point verbal numerical rating scale, retching or vomiting) was higher in the ondansetron group than in the dexamethasone and ondansetron group (15/61 (25%) vs 6/62 (10%, respectively, p = 0.028). Combined dexamethasone and ondansetron is more effective in reducing severe nausea and vomiting than ondansetron alone in patients receiving fentanyl‐based intravenous patient‐controlled analgesia.