It is a method of choice if the patient requires a low FiO2 or after stabilization of acute respiratory distress. Beyond 5 l/min, it is necessary to change the device because it is no longer sufficiently effective and there is a risk of nasal irritation.
The ROX index makes it possible to predict the success or failure of treatment of acute respiratory distress with high nasal flow (Optiflow™ type) in the context of pneumonia.
A ROX index ≥ 4.88 at h2, h6 or h12 of treatment is predictive of successful nasal high flow treatment. A ROX index ≤ 2.85 at h2, 3.47 at h6 or 3.85 at h12 is predictive of failure of nasal high flow treatment and a need for intubation.
Note: FiO2 should be recorded as a percentage (from 21% to 100%)