Abstract: Objective Application of ondansetron is aimed at reducing the postoperative nausea and vomiting.Methods 180 patients who underwent abdomen or chest operation(90-each) were randomly divided into 3 groups.Ondansetron group Ⅰ: The patients received a bolus of ondansetron 4 mg(in normal saline 20 mL) intravenously during operations.Ondansetron group Ⅱ: The patients received a bolus of ondansetron 4 mg(in normal saline 20 mL) intravenously during operations,and repeatedly received ondansetron 4 mg(in normal saline 20 mL) 8 h there after.Control group: The patients received a bolus of normal saline 20 mL during operations.Results Observing the postoperative nausea and vomiting,it showed that the incidence and intensity of nausea for both group Ⅰ and Ⅱ after abdomen and chest operations were much lower than the control group(P<0.05).Conclusion Ondansetron has a significant effect on preventing the occurrence of postoperative nausea and vomiting.

Key words: nausea, vomiting, ondansetron