Right to Left Intrapulmonary Shunt in a Case with COVID-19-associated Pneumonia.

The clinical manifestations of coronavirus disease 2019 (COVID-19)-associated pneumonia show a wide range of variations. It ranges from mild hypoxemia without significant signs of respiratory distress, to rapid clinically deteriorating course with severe hypoxemia. Unexplained severe hypoxemia, associated with platypnea, triggers the possibility of ventilation-perfusion (V/Q) mismatch, ranging from intrapulmonary shunts (IPS) to alveolar dead space ventilation. In the literature, very few cases with COVID-19-pneumonia have been reported with IPS. Herein, we report a COVID-19 confirmed 45-year male patient, who developed IPS without apparent pulmonary perfusion defect on lung perfusion scintigraphy. The patient had no cardiovascular disease except chronic pulmonary hypertension secondary to interstitial lung disease. The clinical manifestations combined with nuclear imaging features enabled in making the ultimate diagnosis. The patient's clinical condition improved on appropriate clinical management, using high flow oxygen combined with intravenous steroids and anticoagulants. Key Words: COVID-19, Adult respiratory distress syndrome, Right to left shunt, Lung perfusion scintigraphy, Platypnea.