Pronation in COVID-19 Patients Undergoing Non Invasive Respiratory Support

Inclusion Criteria: Inclusion Criteria * patients aged ≥18 and \< 80 years old * acute respiratory failure Exclusion Criteria: * endotracheal intubation performed within the first 24 hours from admission, * ceiling of escalation of intensive care * do not intubate order as expressed by patient willing or upon clinical judgement * missing core data at medical record analysis (clinical features at baseline, pronation information, type and time of ventilatory support required, mortality, need for tracheostomy, length of respiratory intensive care unit and hospital stay).