Participants timeline
| Actions | Preinclusion | Inclusion | Pre-O2 (NIV or HFNC) | Intubation | Intubation +5 min +30 min +H6 H12 | Day 1 to 3, to 7 | ICU discharge or day 28 |
| Screening inclusion/non-inclusion criteria | X | ||||||
| Informed consent | X | ||||||
| Randomisation | X | ||||||
| Demographic data | X | ||||||
| Clinical data and SpO2 recording | X | X | X | X | X | ||
| Arterial blood gas | X | X | X | ||||
| Chest X-ray | X | After intubation | X | ||||
| SOFA score, SAPS II | X | X (SOFA) | |||||
| Ventilator-associated pneumonia | X | X | |||||
| Outcomes | X |
HFNC, high-flow nasal cannulae oxygen therapy; ICU, intensive care unit; NIV, non-invasive ventilation; Pre-O2, preoxygenation; SAPS, Simplified Acute Physiology Score; SOFA, Sequential Organ Failure Assessment; SpO2, pulse oxymetry.