Detection of Pulmonary Shunts by Transcranial Doppler in Hospitalized Non-mechanically Ventilated Coronavirus Disease-19 Patients.

In severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-associated disease coronavirus disease 2019 (COVID-19), hypoxemia mechanisms differ from those observed in acute respiratory distress syndrome. Hypoxemia and respiratory failure in COVID- 19 are attributed to pulmonary angiopathy, increasing physiological pulmonary shunting1-3.