Intravenous ondansetron in established postoperative emesis in children. S3A-381 Study Group.

BACKGROUND

In pediatric postsurgical patients, postoperative vomiting is a common occurrence that can delay recovery and result in unplanned hospital admissions after outpatient surgery. This randomized, double-blind, placebo-controlled, multicenter study evaluated the efficacy and safety of ondansetron in the control of established postoperative emesis in outpatients aged 2-12 yr.

METHODS

Screened for the study were 2,720 ASA physical status 1-3 children undergoing outpatient surgery during general anesthesia, which included nitrous oxide. Children experiencing two emetic episodes within 2 h of discontinuation of nitrous oxide were given intravenous ondansetron (n = 192; 0.1 mg/kg for children weighing < or = 40 kg; 4 mg for children weighing > 40 kg) or placebo (n = 183).

RESULTS

The proportion of children with no emetic episodes and no use of rescue medication was significantly greater (P < 0.001) in the ondansetron group compared with placebo for both 2- and 24-h periods after study drug administration (78% of the ondansetron group and 34% of the placebo group for 2 h; 53% of the ondansetron group and 17% of the placebo group for 24 h). Among patients with at least one emetic episode or with rescue medication use, the median time to onset of emesis or rescue was 127 min in the ondansetron group compared with 58 min in the placebo group (P < 0.001). The median time from study drug administration until discharge was significantly shorter (P < 0.01) in the ondansetron group (153 min, range 44-593 min) compared with the placebo group (173 min, range 82-622 min). The incidence of potentially drug-related adverse events was similar in the ondansetron (3% of patients) and the placebo (4% of patients) groups.

CONCLUSION

A single dose of ondansetron (0.1 mg/kg up to 4 mg) is effective and well tolerated in the prevention of further episodes of postoperative emesis in children after outpatient surgery. Administration of ondansetron also may result in a shorter time to discharge.