1) Patients aged = 18 years.2) Virological diagnosis by RT-PCR of infection to SARS-CoV-2.3) Patients in serious or critical condition.4) Acute respiratory failure according to clinical and Berlin criteria (imaging and oxygenation).5) Voluntariness of the patient through informed consent.

1) Patients aged = 18 years.2) Virological diagnosis by RT-PCR of infection to SARS-CoV-2.3) Patients in serious or critical condition.4) Acute respiratory failure according to clinical and Berlin criteria (imaging and oxygenation).5) Voluntariness of the patient through informed consent.

1) Patients aged >= 18 years. 2) Virological diagnosis by RT-PCR of infection to SARS-CoV-2. 3) Patients in serious or critical condition. 4) Acute respiratory failure according to clinical and Berlin criteria (imaging and oxygenation). 5) Voluntariness of the patient through informed consent.

1) Patients aged >= 18 years. 2) Virological diagnosis by RT-PCR of infection to SARS-CoV-2. 3) Patients in serious or critical condition. 4) Acute respiratory failure according to clinical and Berlin criteria (imaging and oxygenation). 5) Voluntariness of the patient through informed consent.