Predictors and Outcomes of Bronchodilator Use in Critical Bronchiolitis

Objective: The role of bronchodilators in bronchiolitis remains unclear, yet they are commonly used. We evaluated their impact in children based on family history of atopy and viral etiology (RSV and rhinovirus). Methods: This was a single-center, retrospective study of children ≤ 2 years admitted to the PICU, step-down ICU, or cardiothoracic ICU who required high-flow nasal cannula, non-invasive ventilation, or invasive ventilation. Patients were categorized by bronchodilator use and stratified by family history of atopy. Primary outcomes were ICU and hospital length of stay (LOS) and length of respiratory support (LRS). The Critical Bronchiolitis Score (CBS) was used to adjust for illness severity by calculating predicted outcomes and comparing them with the observed values. Secondary analysis evaluated outcomes based on family history of atopy and RSV/ rhinovirus positivity. Results: Of 105 included patients, 56 (53.3%) received bronchodilators. The no-bronchodilator group had shorter ICU-LOS (1.7 vs. 2.5 days; p = 0.0005) and hospital LOS (2.1 vs. 3.4 days; p = 0.0038) compared to the bronchodilator group. Predicted ICU outcomes did not differ between groups. Secondary analyses suggested differences in ICU-LOS (p = 0.007) and hospital LOS (p = 0.02) based on family history of atopy. In rhinovirus-positive patients, both ICU and hospital LOS were shorter without bronchodilators, while no differences were observed in RSV-positive patients. Conclusions: Bronchodilators in critical bronchiolitis were associated with longer inpatient LOS, despite similar predicted illness severity. Neither a family history of atopy nor rhinovirus/RSV positivity affected bronchodilator outcomes. Future prospective research is needed to identify targeted subgroups of patients who may benefit from this therapy.