Platypnea-orthodeoxia: bilateral lower-lobe pulmonary emboli and review of associated pathophysiology and management.

Platypnea-orthodeoxia is a rare syndrome characterized by dyspnea and arterial deoxygenation, which is exacerbated in an upright position and relieved with recumbency. We report a case of platypnea-orthodeoxia in a 56-year-old male who was found to have bilateral lower-lobe pulmonary emboli. He did not have any evidence of an intracardiac shunt. A comprehensive review of the pathophysiology and management of platypnea-orthodeoxia is provided.