Table 1 Inclusion and exclusion criteria

 ≥ 18 years of age

 < 18 years of age

The ability to understand and sign the informed consent (in case of unconsciousness consent is obtained from the next of kin)

History of chronic pulmonary disease with PaCO₂ > 50 mmHg or history of using oxygen at home

Evidence of pneumonia by chest CT-scans and/or confirmation of SARS-CoV-2 by qRT-PCR

Pregnancy or breastfeeding

Bilateral opacity of the lungs on CT scan

History of pulmonary embolism or DVT in the past three months

Requires mechanical ventilation to increase oxygen saturation

History of lung transplantation

PaO₂/FiO₂ ratio ≤ 200

Existence of active malignancy that has been treated for the past two years

More than 96 h have passed since the diagnosis of ARDS (the Berlin definition of ARDS)

Moderate to severe liver failure (Childs-Pugh Score > 12)

Extensive trauma in the last 5 days

Existence of severe and irreversible disease with a probability of life expectancy of fewer than 6 months