To assess the hypothesis that ondansetron administration to children with type 1 diabetes mellitus (T1DM) presenting for emergency department (ED) care with intercurrent illness and vomiting improves clinical outcomes by reducing hospitalization rates (primary), length of ED stay, intravenous fluid (IVF) administration, and revisits (secondary outcomes).

We conducted a single-center, 10-year retrospective cohort study of 345 ED encounters of children aged 6 months-8 years with T1DM and vomiting. We compared outcomes among children receiving and not receiving ondansetron. To avoid selection bias related to ondansetron administration, we also investigated outcomes by conducting comparisons by ondansetron usage periods (ie, low [2002-2004] vs high [2009-2011]).

Ondansetron usage increased from 0% to 67% of ED encounters between 2002 and 2011. Admission rates were similar among those administered [54% (58/107)] and not administered ondansetron [55% (131/238)]. Length of stay was longer in children receiving ondansetron (409 vs 315 minutes; P = .03). IVF administration (77% vs 77%) and revisits (5.6% vs 5.9%) were similar. Ondansetron administration was not associated with reduced admission in logistic regression modeling. Admission rate (62%; 56/91 vs 49%; 57/111) (−13%, 95% CI −23%, 3%), length of stay (395 vs 327 minutes [IQR 164 501]; P < .001), and IVF administration decreased (84% [77/91] to 70% [78/111]; P = .02] when comparing low and high ondansetron usage periods.

Ondansetron administration was not independently associated with lower admission rates. Over time, along with increasing ondansetron use, there have been reductions in admissions, length of stay, and IVF administration in children with T1DM.