Single-Dose Prophylaxis for Postoperative Nausea and Vomiting after Major Abdominal Surgery: Ondansetron versus Droperidol

Abstract

The new antiemetic ondansetron is effective for the prophylaxis and treatment of postoperative nausea and vomiting (PONV), but has been subject to limited comparative evaluation in surgical inpatients. Two hundred and seventy women having abdominal gynaecological surgery were investigated for 24 hours postoperatively in a randomized, double-blind, placebo-controlled study of intraoperative intravenous ondansetron 8 mg (n=83), droperidol 2.5 mg (n = 89) or saline placebo (n=87). Patients receiving either ondansetron or droperidol remained likely to vomit, although the incidence was significantly reduced compared with placebo (72% and 83% versus 91%, P<0.01). Both drugs also resulted in significantly fewer vomiting episodes (P<0.001), lower nausea scores (P<0.05) and a lower incidence of patients requiring treatment for PONV (P<0.01). Compared with droperidol, the risk of vomiting after ondansetron was less (odds ratio 0.5, CI 0.3–1.0). Ondansetron resulted in fewer vomiting episodes (P<0.05) and a higher percentage of patients free of nausea after six hours postoperatively (P<0.05). In patients with a past history of PONV, both drugs had a similar short-lived antiemetic effect, reducing the incidence of vomiting and the need for treatment while in the recovery room, but not thereafter. Droperidol was associated with significantly less headache (P<0.05), but higher early sedation scores (P<0.05). Although, compared to placebo, both droperidol and ondansetron administered intraoperatively reduced vomiting after major abdominal gynaecological surgery, the incidence during the first 24 postoperative hours was very high in all groups. Ondansetron reduced the risk of experiencing nausea after six hours postoperatively and the risk of vomiting, with respect to the total number of episodes, in the first 24 hours. It was no better than droperidol, however, in reducing the incidence of vomiting or the need for antiemetic treatment during the first postoperative day, whether or not patients had a past history of PONV.