From Floor to Intensive Care Unit: Unpacking the Real Impact of High-Flow Nasal Cannula on Bronchiolitis Triage

BACKGROUND: High-flow nasal cannula (HFNC) therapy is increasingly used for infants with bronchiolitis on general pediatric wards, yet factors associated with pediatric intensive care unit (PICU) transfer and escalation beyond HFNC remain poorly defined. Our aim was to characterize clinical trajectories of infants started on HFNC on the pediatric floor and identify factors associated with PICU admission and escalation of respiratory support. METHODS: We conducted a retrospective cohort study of children younger than 24 months of age admitted with bronchiolitis to a tertiary children's hospital pediatric ward between January 2020 and October 2022, who received HFNC ≥0.5 L/kg/min. Multivariable logistic and linear regression models were used to identify factors associated with PICU admission, escalation beyond HFNC, length of oxygen requirement, and hospital length of stay. RESULTS: Among 200 patients (median age, 7 months; median weight, 7.7 kg), 51.5% were transferred to the PICU, whereas 13.5% required escalation beyond HFNC. Most (86.5%) were successfully weaned from HFNC without escalation past HFNC. Height, weight, and initial HFNC flow were not independently associated with PICU admission nor escalation past HFNC in the adjusted models. However, longer time from HFNC initiation to peak flow rate was independently associated with escalation beyond HFNC. PICU admission, even without escalation past HFNC, was associated with significantly longer hospital length of stay and duration of oxygen therapy. CONCLUSION: Most infants with bronchiolitis initiated on HFNC on the pediatric floor do not require escalation beyond HFNC. These findings support the need for standardized, physiology-based triage criteria rather than reliance on fixed HFNC flow thresholds to optimize PICU use and equity of care.