Awake Prone Positioning in Spontaneous Breathing Patients With Acute Hypoxic Respiratory Failure Due to Pneumonia

Inclusion Criteria: * The focus of this trial is to treat patients with respiratory failure. The inclusion criteria are selected accordingly. Patients meeting all of the criteria listed below will be included in the study: * Patients in the intensive care unit * High possibility of Pneumonia (community-acquired pneumonia or hospital-acquired pneumo-nia) either diagnosed by chest x-ray or computed tomography or clinically diagnosed at least with one of the following signs * Appearance of purulent secretions or changes in characteristics (color, odor, quantity, consistency) * Cough or dyspnea or tachypnea * Evocative auscultation * Presence of acute hypoxemic respiratory failure (PaO2/FIO2 ≤ 300 mmHg or SpO2/FiO2 ≤ 315) Exclusion Criteria: * Patients are excluded from the study if any of the following criteria are met at screening or before ran-domization, a detailed list is shown in the study manual: * Age below 18 * Pregnant woman * Patient is unlikely/unable to awake prone positioning, or to be compliant as indicated by the treating team * Prolonged need (≥ 4 days) for HFNO, NIV or CPAP before study inclusion * Urgent need for endotracheal intubation * Invasive Mechanical Ventilation * Shock o Defined as need for vasopressor ≥ 0.4 mcg/kg/min to maintain a mean blood pressure of ≥ 65 mmHg or systolic blood pressure ≥ 90 mmHg * Participation in another clinical interventional trial in the last 3 months * Previous Participation in the PROSA Trial * Long-term oxygenation therapy (LTOT) or continuous positive airway pressure (CPAP) therapy before hospital admission * Treatment