inclusion criteria: * patients who are admitted to hospital centers with a positive rt-qpcr sars-cov-2 test or a ct scan compatible with a diagnosis of covid-19 pneumonia, in addition to one of the following two criteria: 1. severe respiratory failure \[respiratory rate\> 25 - \<35 x minute, oxygen saturation ≤ 90% with reservoir mask (fio2 = 100%)\] 2. requiring invasive mechanical ventilation.

inclusion criteria: * patients who are admitted to hospital centers with a positive rt-qpcr sars-cov-2 test or a ct scan compatible with a diagnosis of covid-19 pneumonia, in addition to one of the following two criteria: 1. severe respiratory failure \[respiratory rate\> 25 - \<35 x minute, oxygen saturation ≤ 90% with reservoir mask (fio2 = 100%)\] 2. requiring invasive mechanical ventilation.

inclusion criteria: patients who are admitted to hospital centers with a positive rt-qpcr sars-cov-2 test or a ct scan compatible with a diagnosis of covid-19 pneumonia, in addition to one of the following two criteria: severe respiratory failure [respiratory rate> 25 - <35 x minute, oxygen saturation ≤ 90% with reservoir mask (fio2 = 100%)] requiring invasive mechanical ventilation.

inclusion criteria: patients who are admitted to hospital centers with a positive rt-qpcr sars-cov-2 test or a ct scan compatible with a diagnosis of covid-19 pneumonia, in addition to one of the following two criteria: severe respiratory failure [respiratory rate> 25 - <35 x minute, oxygen saturation ≤ 90% with reservoir mask (fio2 = 100%)] requiring invasive mechanical ventilation.

inclusion criteria: - patients who are admitted to hospital centers with a positive rt-qpcr sars-cov-2 test or a ct scan compatible with a diagnosis of covid-19 pneumonia, in addition to one of the following two criteria: 1. severe respiratory failure [respiratory rate> 25 - <35 x minute, oxygen saturation ≤ 90% with reservoir mask (fio2 = 100%)] 2. requiring invasive mechanical ventilation.

inclusion criteria: - patients who are admitted to hospital centers with a positive rt-qpcr sars-cov-2 test or a ct scan compatible with a diagnosis of covid-19 pneumonia, in addition to one of the following two criteria: 1. severe respiratory failure [respiratory rate> 25 - <35 x minute, oxygen saturation ≤ 90% with reservoir mask (fio2 = 100%)] 2. requiring invasive mechanical ventilation.