Table 1 Inclusion and exclusion criteria

Age > 18 years

Reverse transcriptase–polymerase chain reaction -confirmed SARS–CoV-2 infection

Berlin criteria-defined acute respiratory distress syndrome for < 96 h

Respiratory support (invasive or non-invasive mechanical ventilation, and/or high-flow nasal oxygenation) with positive end-expiratory pressure equivalent ≥ 5 cm H₂O

Age < 18 years

Acute respiratory distress syndrome present for > 96 h

Pulmonary fibrosis

Pulmonary hypertension (WHO classification class III or IV)

Pulmonary embolism within the previous 3 months

Extracorporeal membrane oxygenation or life support

Immunocompromised status including use of immunosuppressive medications

Pregnancy or breastfeeding

Treatment for cancer in the past 2 years

Underlying medical condition with life expectancy < 6 months

Moderate-to-severe liver disease (Child–Pugh score > 12)

Severe chronic lung disease with the use of home oxygen and/or partial arterial pressure of carbon dioxide > 50 mm Hg

Patients not committed to full support (i.e., had do not resuscitate or limit life support orders)

Participation in another trial of COVID-19 therapeutics