SINGLE-DOSE PROPHYLAXIS FOR POSTOPERATIVE NAUSEA AND VOMITING AFTER MAJOR ABDOMINAL-SURGERY - ONDANSETRON VERSUS DROPERIDOL

The new antiemetic ondansetron is effective for the prophylaxis and tr eatment of postoperative nausea and vomiting (PONV) but has been subje ct to limited comparative evaluation in surgical inpatients. Two hundr ed and seventy women having abdominal gynaecological surgery were inve stigated for 24 hours postoperatively in a randomized, double-blind, p lacebo-controlled study of intraoperative intravenous ondansetron 8 mg (n = 83), droperidol 2.5 mg (n = 89) or saline placebo (n = 87). Pati ents receiving either ondansetron or droperidol remained likely to vom it, although the incidence was significantly reduced compared with pla cebo (72% and 83% versus 91%, P< 0.01). Both drugs also resulted in si gnificantly fewer vomiting episodes (P < 0.001), lower nausea scores ( P < 0.05) and a lower incidence of patients requiring treatment for PO NV(P < 0. 01). Compared with droperidol, the risk of vomiting after on dansetron 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 patien ts free of nausea after six hours postoperatively (P<0.05). In patient s with a past history of PONV both drugs had a similar short-lived ant iemetic effect, reducing the incidence of vomiting and the need for tr eatment while in the recovery room, but not thereafter. Droperidol was associated with significantly less headache (P< 0.05), but higher ear ly sedation scores (P< 0.05). Although, compared to placebo both drope ridol and ondansetron administered intraoperatively reduced vomiting a fter 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 postoperativel y and the risk of vomiting, with respect to the total number of episod es, in the first 24 hours. It was no better than droperidol, however, in reducing the incidence of vomiting or the need for antiemetic treat ment during the first postoperative day, whether or not patients had a past history of PONV.