Comparing High-flow Nasal Cannula Oxygen and Noninvasive Ventilation to Standard Oxygenation in Non-selected ICU Patients Admitted for Hypoxemic ARF (KISS)

Inclusion Criteria: Adult (age ≥ 18 years) A diagnosis of hypoxemic ARF occurring defined as the presence and persistence for more than 30 minutes of hypoxemia (defined by a partial oxygen pressure <60 mm Hg when breathing room air or <80 mmHg when breathing 15 L/min of oxygen or a peripheral oxygen saturation [SpO2] ≤90% when breathing room air and/or a PaO2(partial pressure of oxygen)/FiO2 ratio < 300 mmHg plus either [1] a respiratory rate higher than 30/min or [2] clinical signs suggestive of intense respiratory muscle work and/or labored breathing, such as use of accessory respiratory muscles, paradoxical motion of the abdomen, or intercostal retraction). Exclusion Criteria: Contraindications to NIV and/or HFNO Sleep apnea syndrome with home ventilator Immediate tracheal intubation Requirement for an emergent surgical procedure Hypercapnia with a formal indication for NIV (formal indication for NIV with PaCO2 ≥ 50 mmHg or clinical signs of hypercapnia) Isolated cardiogenic pulmonary edema (formal indication for NIV). Patients with pulmonary edema associated with another ARF etiology can be included. Anatomical factors precluding the use of NIV and/or HFNO Previous ARF in the last month Pregnancy in progress or planned during the study period or breastfeeding women Patients protected by law (Art. L1121-6 and L1121-8 of the Code de la Santé Publique): Adult protected by law or patient under guardianship or curatorship Subjects not covered by public health insurance Absence of written informed consent from the patient or his or her proxy (if present) before inclusion or when possible when the patient has been included in an emergency setting