Triage Administration of Ondansetron for Gastroenteritis in Children: A Randomized Controlled Trial.

OBJECTIVES: Acute gastroenteritis is a leading cause of pediatric emergency department (ED) visits. While ondansetron reduces vomiting, intravenous rehydration, and hospital admissions, its efficacy when initiated at triage remains unclear. We aimed to evaluate whether triage nurse-initiated administration of ondansetron in children with suspected gastroenteritis reduces the proportion of patients who had observation following initial physician assessment. METHODS: We conducted a randomized, double-blind, placebo-controlled trial in a tertiary pediatric ED in Canada. Children aged 6 months to 17 years presenting with ≥4 episodes of vomiting in the preceding 24 hours (including ≥1 within 2 h of arrival) were eligible. At triage, we randomized participants to receive liquid ondansetron or a color- and taste-matched placebo. The primary outcome was the proportion of patients who had observation after the first physician evaluation. Secondary outcomes included postintervention vomiting, ED length of stay, patient comfort, and 48-hour return visits. The trial was registered at clinicaltrials.gov (NCT03052361). RESULTS: Recruitment was stopped prematurely due to the coronavirus disease 2019 pandemic. Ninety-one participants were randomized to ondansetron (n = 44) or placebo (n = 47). Overall, 40 patients (45%) were discharged immediately after the initial physician assessment, with no difference between the ondansetron and placebo groups (44% vs. 45%; absolute difference: -1%, 95% CI: -20% to 19%). No significant differences were observed in any secondary outcomes. CONCLUSION: This trial failed to show an impact of triage nurse-initiated ondansetron administration in children with presumed gastroenteritis. Although underpowered to assess any outcome, our results could inform researchers planning larger trials.