BACKGROUND: Postoperative nausea and vomiting are a 'Big Little Problem' during IV-PCA after vaginal total hysterectomy. This study was designed to determine the effect of dosage and the method of ondansetron administration on the incidence of postoperative nausea and vomiting in patients that received intravenous patient-controlled analgesia (IV-PCA).

METHODS: Sixty ASA I-II patients that underwent elective total vaginal hysterectomy and received postoperative IV-PCA were randomly divided into three groups according to dosage and the timing of ondansetron administration. These patients were given ondansetron; twice, (4 mg each) after induction and 5 minutes before the end of the operation (group 1); 8 mg 5 minutes before the end of the operation (group 2); and twice, (8 mg each) after induction and 5 minutes before the end of the operation (group 3). The incidences of nausea and vomiting and pain scores by visual analogue scale (VAS) were checked and recorded in recovery rooms and wards at 1, 6, 24, and 48 hours after operation, respectively.

RESULTS: The three groups showed no significant differences in terms of the incidences of nausea and vomiting and had similar VAS pain scores.

CONCLUSIONS: Our findings suggest that ondansetron dosage and methods of its administration are not effective at reducing the incidence of postoperative nausea and vomiting.