Effect of ondansetron in preventing postoperative nausea and vomiting under different conditions of general anesthesia: A preliminary, randomized, controlled study

Methods. Two hundred and forty patients were randomly allocated into six groups: Group I, anesthesia was maintained with sevoflurane; Group II, anesthesia was maintained with sevoflurane and 8 mg of ondansetron; Group III, anesthesia was maintained with propofol; Group IV, anesthesia was maintained with propofol and 8 mg of ondansetron; Group V, anesthesia was maintained with sevoflurane and propofol; Group VI, anesthesia was maintained with sevoflurane combined with propofol and 8 mg of ondansetron. Results. We found that the incidence of vomiting was lower in group II (17.5%), group IV (7.5%), and group VI (10%) compared with group I (55%), group III (27.5%), and group V (30%), respectively (P < 0.05). The incidence of vomiting was also lower in group III (27.5%) and group V (30%) when compared with group I (55%) (P < 0.05). The incidence of nausea was 55% in group I, 42.5% in group II, 30% in group III, 27.5% in group IV, 30% in group V, and 30% in group VI. Groups III and V had a lower incidence of nausea than group I (P < 0.05). Conclusions. We conclude that compared with sevoflurane anesthesia alone, anesthesia with either propofol alone or propofol combined with sevoflurane resulted in a reduced incidence of vomiting and nausea during the first 24h after surgery. Administration of ondansetron effectively reduced the incidence of vomiting but not that of nausea for all three types of general anesthesia.