confirmation of Covid-19 diagnosis by PCR test informed consent to participate in the study No history of allergy to methylxanthines Being hospitalized in the intensive care unit The patient should not be intubated arterial oxygen saturation less than 85% without oxygen therapy(room air or ambient air)

confirmation of Covid-19 diagnosis by PCR test informed consent to participate in the study No history of allergy to methylxanthines Being hospitalized in the intensive care unit The patient should not be intubated arterial oxygen saturation less than 85% without oxygen therapy(room air or ambient air)