Antiemetic efficacy of combined aprepitant and dexamethasone in patients at high-risk of postoperative nausea and vomiting from epidural fentanyl analgesia.

BACKGROUND: Postoperative opioid analgesia increases the incidence of postoperative nausea and vomiting (PONV). We investigated whether a combination of the neurokinin-1 antagonist aprepitant and dexamethasone decreases PONV incidence compared with dexamethasone alone in high-risk patients receiving continuous epidural fentanyl.

METHODS: Sixty nonsmoking female patients scheduled for elective knee osteoarthritis surgery were randomly allocated to receive oral aprepitant 80 mg (aprepitant+dexamethasone group, N.=30) 2 h before anesthesia induction or no oral aprepitant (dexamethasone group, N.=30). All patients received intravenous dexamethasone 8 mg immediately before anesthesia induction. Anesthesia was maintained with remifentanil and sevoflurane. Continuous infusion of epidural analgesia, including fentanyl, was provided during and after surgery. We assessed complete response (no PONV and no rescue antiemetic use), incidence of nausea and vomiting, nausea severity scale, vomiting frequency, rescue antiemetic use, and postoperative pain at 2 and 24 h after surgery.

RESULTS: The cumulative incidence of vomiting at 24 h was 3% in the aprepitant+dexamethasone group and 27% in the dexamethasone group (P=0.011). The incidence and frequency of vomiting in the late postoperative period was also significantly lower in the aprepitant+dexamethasone group than in the dexamethasone group. However, there were no significant group differences in the proportion of patients who experienced a complete response, the incidence and severity of nausea, and rescue antiemetic use at 24 h.

CONCLUSION: The combination of aprepitant and dexamethasone was more effective in preventing postoperative vomiting compared with dexamethasone alone in patients at high-risk of PONV from continuous epidural fentanyl analgesia.