Awake Prone Position to Reduce Ventilation Inhomogeneity in COVID-19 Acute Respiratory Failure

Inclusion Criteria: * more than 18 Years (Adult, Older Adult) * Confirmed COVID-19 (positive SARS-CoV-2 RT-PCR at nasopharyngeal swab) * Acute respiratory failure with 100 \< PaO2:FiO2\< 300 mmhg * Spontaneous ventilation with standard oxygen supply or high flow humidified oxygen * Written informed consent of the patient Exclusion Criteria: * Contra-indication to prone position including pregnancy * Presence of pacemaker * Severe hypoxemia with PaO2/FiO2 \< 100 mmHg * Evidence of clinical signs of respiratory distress with high probability of intubation in the next two hours