inclusion criteria: * hospitalized, covid-19 positive, between 18 and ≤ 85 years of age; * signed inform consent form; * body temperature \> 37.3 ℃; * oxygenation criterion (any of the following): i) oxygen saturation ≤94% on room air; ii) pao2/fio2 ratio ≤300 mmhg but \> 100 mmhg, if patient on supplemental oxygen; iii) spo2/fio2\<200 if no arterial blood gas available; * respiratory rate (rr) ≥ 25 beats/min.

inclusion criteria: * hospitalized, covid-19 positive, between 18 and ≤ 85 years of age; * signed inform consent form; * body temperature \> 37.3 ℃; * oxygenation criterion (any of the following): i) oxygen saturation ≤94% on room air; ii) pao2/fio2 ratio ≤300 mmhg but \> 100 mmhg, if patient on supplemental oxygen; iii) spo2/fio2\<200 if no arterial blood gas available; * respiratory rate (rr) ≥ 25 beats/min.

inclusion criteria: - hospitalized, covid-19 positive, between 18 and ≤ 85 years of age; - signed inform consent form; - body temperature > 37.3 ℃; - oxygenation criterion (any of the following): i) oxygen saturation ≤94% on room air; ii) pao2/fio2 ratio ≤300 mmhg but > 100 mmhg, if patient on supplemental oxygen; iii) spo2/fio2<200 if no arterial blood gas available; - respiratory rate (rr) ≥ 25 beats/min.

inclusion criteria: - hospitalized, covid-19 positive, between 18 and ≤ 85 years of age; - signed inform consent form; - body temperature > 37.3 ℃; - oxygenation criterion (any of the following): i) oxygen saturation ≤94% on room air; ii) pao2/fio2 ratio ≤300 mmhg but > 100 mmhg, if patient on supplemental oxygen; iii) spo2/fio2<200 if no arterial blood gas available; - respiratory rate (rr) ≥ 25 beats/min.