A randomized controlled trial of the antiemetic effect of three doses of ondansetron after strabismus surgery in children

Abstract

Methods: One hundred and thirty-one healthy children, aged 31-152 months, undergoing strabismus surgery under general anaesthesia, were randomly allocated to one of four groups: group A received 0.04 mg.kg-1 ( identical with 1 mg.m-2) of ondansetron, group B 0.1 mg.kg-1 ( identical with 2.5 mg.m-2), group C 0.2 mg.kg-1 ( identical with 5 mg.m-2) and group D placebo, given intravenously following induction of anaesthesia. Morphine 0.15 mg.kg-1 was given intravenously, intraoperatively, to provide postoperative analgesia. Hourly records of emetic episodes were made for 24 h.

Results: A considerably higher proportion of children suffered emesis in the placebo group compared to the active treatment groups taken together, during the first 8 h of postoperative care (76% vs. 45%, P=0.002). During the first 8 h, only 25% of those in treatment group C suffered emesis, the number-needed-to-treat was 3. There was a statistically significant decrease in the chance of vomiting with increasing dose of ondansetron (P=0.03). By 24 h, the difference in the rate of emesis was less marked but still statistically significant (90% vs. 69%, P=0.03).

Conclusion: Overall, children given ondansetron had less than one-half the risk of vomiting compared to those given placebo (hazard ratio 0.46, 95% confidence interval 0.29-0.74). The mean number of emetic episodes declined from 2.73 in the placebo group to 1.92 in treatment group C. There was no difference in the incidence of side-effects between groups.