Impact of initial flow rate of high‐flow nasal cannula on clinical outcomes in infants with bronchiolitis

Aim Bronchiolitis is a common condition in the paediatric population. Severe cases often receive respiratory support with high‐flow nasal cannula (HFNC). Significant variation in the application of HFNC exists throughout Australia and internationally. This study aimed to determine if the flow rate used initially and when ceasing HFNC at the end of the illness alters clinical outcomes. Methods A retrospective analysis was conducted of 251 children less than 12 months of age when admitted to the Women's and Children's Hospital Adelaide with bronchiolitis requiring HFNC therapy between the period of April 2016 to April 2019. The primary outcome was to determine if commencing HFNC therapy at different rates (1 L/kg/min, 1.5 L/kg/min and 2 L/kg/min) affected length of stay or treatment failure (escalation in physiological parameters or respiratory support). Results Treatment failure occurred in 33%, 13% and 26% of those starting at 1 L/kg/min, 1.5 L/kg/min and 2 L/kg/min, respectively. Commencing HFNC therapy at 1 L/kg/min increased length of stay by an average of 30 h (P