Predictive factors for the outcome of high flow nasal cannula therapy in a pediatric intensive care unit: Is the SpO2/FiO2ratio useful?

Objectives To determine the predictive factors for the outcome of high-flow nasal cannula (HFNC) therapy in a pediatric intensive care unit (PICU). Materials and methods We prospectively included all patients with acute respiratory distress/failure aged 1month to 18years who were admitted to the PICU between January 2015 and May 2016 and treated with HFNC as a primary support and for postextubation according to our pre-established protocol. HFNC failure was defined as the need for escalation to non-invasive ventilation (NIV) or invasive mechanical ventilation (MV). HFNC responders and nonresponders were compared based on clinical data obtained just before HFNC and at 30, 60, and 120min, 12, 24, and 48h, and at the end of therapy. Results A total of 204 patients (median age: 16.5months) participated in the study. Twenty-six (12.7%) patients required escalation (4 to NIV and 22 to MV). Age >120months, higher PRISM-III and respiratory scores, and a lower SpO2/FiO2(S/F) ratio at admission were predictors of HFNC failure. Achievement of the S/F>200 goal at 60min significantly predicted successful HFNC. Conclusion Monitoring the S/F ratio might be useful and practical to avoid delaying escalation to another ventilation support. Failure to achieve S/F>200 at 60min should be a warning for the escalation of respiratory support.