ABSTRACT
The relationship between the severity of COVID-19, hyperinflammation, and intravascular coagulopathy is of critical importance. We report on a case of severe COVID-19 pneumonia treated with favipiravir during the earliest phase of the pandemic. The present case showed improvement in SARS-CoV-2 viral load and the presence of SARS-CoV-2 IgG with decreased radiological evidence of pulmonary infiltration. Moreover, the levels of serum IL-6 and TNF-α did not increase markedly. However, the hypoxia failed to recover, leading to the patient’s death due to possible pulmonary thrombosis, because D-dimer was markedly elevated, and an electrocardiogram showed typical changes. At present, the fact that some COVID-19 patients with mild to moderate symptoms suddenly die at home has become a major issue in Japan. These findings suggest that additional treatment with anti-coagulants should be considered in some COVID-19 patients at risk of hypercoagulation to prevent sudden death from pulmonary thrombosis.