Increasing Use of Ondansetron and Its Relationship to Intravenous Rehydration Rates in Children With Acute Gastroenteritis

Abstract

Background: Despite evidence that ondansetron use reduces the frequency of vomiting, need for intravenous rehydration and hospitalization; guidelines continue to recommend against its use in pediatric gastroenteritis. Objective: To determine if increasing use of ondansetron is associated with improved clinical outcomes. Design/Methods: A retrospective cohort study was conducted at The Hospital for Sick Children (Toronto, ON). Eligible children included those <18 years of age who presented to the emergency department (ED) between July 2003 and June 2008 and were diagnosed with gastroenteritis. 20% of all eligible patients were selected at random for chart review. The primary outcome was the correlation over time between the proportions of children administered ondansetron and those that received intravenous rehydration. A time trend analysis comparing 2003-05 vs. 2006-08 was conducted using intravenous rehydration as the outcome. A structural model was built using unobserved components and the explanatory variable- ondansetron. Secondary outcomes included length of stay, ED revisits and need for intravenous rehydration upon revisit. Results: 22,125 potentially eligible visits were identified and 4,425 charts were reviewed. There was a trend towards increasing acuity during the 5 year period as reflected by lower CTAS scores (P<0.001). Over the course of the 5-year study period, there was a reduction in the use of intravenous rehydration. from 27% to 13% (P<0.001) and an increase in ondansetron utilization from 1% to 18% (P<0.001). The time series analysis revealed that seasonality was a major determinant in intravenous rehydration rates, and that there were statistically significant downward trends and downward level breaks (all P<0.001). The porportion of children administered ondansetron was a negative predictor of the need for intravenous rehydration (P<0.001). A reduction in the mean length of stay occurred over this time period (8.6 hours to 5.9 hours; P=0.03). During the week following the index visit there was a reduction in return visits to our ED (18% to 13%; P=0.008), and need for intravenous rehydration (7% to 4%; P=0.02). Conclusions: Ondansetron use has increased significantly. This is associated with reductions in intravenous rehydration and ED revisits and a shorter length of stay for children with gastroenteritis. The selective use of ondansetron in the treatment of children with gastroenteritis results in improved clinical outcomes.