Table 1.

Inclusion and exclusion criteria.

Inclusion criteria	Esclusion criteria
Cough, fever, sign of interstitial pneumonia on chest X-Ray, lung ultrasound and/or CT-scan	Chronic obstructive pulmonary disease
History of previous contact with COVID-19 patients	Arterial partial pressure of carbon dioxide >50 mmHg
Patients with a PaO2/FiO2 between 200 and 300, while breathing in room air or through Venturi mask measured after 1 h from hospital admission	Pregnancy
Pulse oxymetry (SpO2) <95% in room air	Contraindication to CPAP
Dyspnoea, as defined by a Borg scale >3