Abstract Background High-flow nasal cannula has been a promising initial respiratory support measure for patients with acute hypoxemic respiratory failure (AHRF) in the emergency department (ED). However. delayed detection of HFNC failure is associated with increased mortality. The ROX index is a tool that can help predict HFNC success. https://lecoureures.shop/product-category/course-a-pied-accessoires-hydratation/