High Flow Nasal Cannula (HFNC) Initiation Flow Rate Study

The investigators propose an open label, non-blinded, single center randomized controlled feasibility study to find the optimal initial HFNC flow rate in children less than 12 months old with clinically diagnosed moderate to severe bronchiolitis. This feasibility study is projected over December 2020 to April 2023. The study is consisted of 3 arms, comparing HFNC therapy at 1 L/kg/min, 1.5 L/kg/min, and 2 L/kg/min (20 L/min max). Moderate to severe bronchiolitis is defined clinician's assessment for the need for ICU level of care. The primary outcome is treatment response to HFNC therapy defined by RDAI/Respiratory Assessment Change Score (RACS) ≥ 4 at 4 hours of therapy. Secondary outcome measures comprise of treatment failure requiring an escalation of care during the first 24 hours of HFNC therapy, duration of HFNC and simple nasal cannula therapy, duration of simple nasal cannula therapy, hospital and PICU length of stay (LOS), time to treatment failure, and adverse events.