Background: Patient-controlled analgesia (PCA) with parenteral opioids is associated with a high incidence of postoperative nausea and vomiting (PONV). The aim of the present study was to compare the efficacy of dexamethasone plus haloperidol with dexamethasone plus ondansetron for the prevention of PCA-related PONV. Patients who received dexamethasone alone were used as controls.
Methods: A total of 135 female patients (n = 45 in each of three groups) were eligible to participate in this randomized trial. A total of 135 female patients (n = 45 in each of three groups) were eligible to participate in this randomized trial. Dexamethasone 5 mg IV was administered after the induction of anesthesia in dexamethasone group (group D) patients. Patients in the dexamethasone plus haloperidol group (group DH) and in the dexamethasone plus ondansetron (group DO) further received haloperidol 2 mg IM or ondansetron 4 mg IV, respectively, 30 min before the end of surgery. The complete response rates, incidence of PONV, need for rescue medication, average pain and sedation scores, recovery times, and adverse events were observed postoperatively.
Results: The incidences of total PONV in the first 24 h in groups DH (35%) and DO (30%) were significantly lower than those of group D (57%) (p < 0.05 for each comparison). The differences between groups DH and DO were insignificant. The incidence of PONV was significantly smaller in the DH and DO groups than predicted by the patients’ underlying risks. Pain scores, sedation scores, and recovery times were similar among the three study groups, and no clinically relevant prolongation of the electrocardiographic QTc interval was observed in any patient. conclusions: Dexamethasone 5 mg with either haloperidol 2 mg or ondansetron 4 mg provides a better antiemetic effect than dexamethasone 5 mg alone in patients receiving postoperative morphine PCA.