Contribution of Nasal High Flow in Pneumology Assessed in Acid-Free Hypercapnic Acute Respiratory Failure

A device that provides high flows of heated and humidified respiratory gases to patient who breath spontaneously. Patients will be treated with the device up to 15 days or until the occurrence of respiratory acidosis defined by pH\<7.35, whichever come first.

Standard therapy depends on the acute respiratory failure etiology. Treatments will be administered at the investigator's discretion in accordance with the standard of care.