Diagnosis of Serious Conditions Delayed in Association with Ondansetron Treatment for Vomiting in the Pediatric Emergency Department.

Objectives: We evaluated the characteristics and sought risk factors for hospitalization in children who return to the emergency department within 7 days of discharge after oral or intravenous ondansetron treatment for vomiting. The secondary aim was to determine whether the diagnosis of any serious condition had been delayed as the result of discharge after ondansetron treatment.

Methods: This retrospective analysis of the medical records of children who had been treated for vomiting with ondansetron in a tertiary care pediatric emergency department and revisited the emergency department within 7 days was performed between 2017 and 2019. We compared demographic and clinical features as well as management between hospitalized and discharged patients, focusing upon potentially delayed diagnoses of serious conditions.

Results: Fifty of the 89 ondansetron-treated children (56.2%) who revisited the emergency department were discharged home after their second emergency department visit and the remaining 39 (43.8%) were hospitalized. No parameter of the management of the first visit was predictive of the outcome of the revisit. Five revisit patients (5.6%) were newly diagnosed with a serious condition, with intussusception and ovarian torsion being the most substantial time-sensitive delays (the other diagnoses were pneumonia and aseptic meningitis).

Conclusions: Physicians assessing patients who had been treated with ondansetron as supportive care for vomiting at an earlier visit to the pediatric emergency department should consider alternative diagnoses despite initial clinical improvement. No definitive risk factor for readmission was identified, but a high level of alertness to a possible meningeal or acute abdominal source is imperative.