Convalescent Plasma as Potential Therapy for Severe COVID-19 Pneumonia

Inclusion Criteria: * Adult patients ≥18, and non-pregnant women * Severe or critical COVID-19 disease define by one or more of the following: blood oxygen saturation ≤ 94% on supplemental oxygen by nasal cannula at least 3 L/min, non-rebreathing mask (NRO2-mask) or on noninvasive ventilation; and pulmonary infiltrates with \>50% increase within 24 to 48 hours in chest-X-ray or chest CT. Life-threatening disease was defined as one or more of the following: respiratory failure on mechanical ventilation with PaO2 / FiO2 less than 300 mm Hg, septic shock, and/or multiple organ dysfunction. * 10 days from the onset of symptoms or ≤ 7 days on mechanical ventilation. - Exclusion Criteria: * More than 10 days from symptoms onset or more than 7 days on mechanical ventilation * Pregnancy * Contraindication for plasma infusion because anaphylaxis history * Patients with high risk of circulatory overload * Limitation of therapeutic efforts * Refractory shock define by norepinephrine dose more than 1 ug/k/min * SOFA score more than 15 points at the moment of the protocol inclusion i Coagulopathy with requirements of plasma infusion