Platypnea–orthodeoxia syndrome associated with COVID-19 pneumonia: a case report

Background: Platypnea–orthodeoxia syndrome (POS) is a rare clinical condition characterized by respiratory distress and/or hypoxia developing in the sitting/upright position, which is relieved in the recumbent position. This syndrome is known to have an intracardiac shunt as its primary etiology. Here, we report the case of a patient who was found to have POS without an intracardiac shunt while recovering from coronavirus disease (COVID-19) pneumonia. Case presentation: A 73-year-old woman was diagnosed with severe COVID-19 pneumonia and was managed according to our institutional protocol. Although her oxygenation improved at rest, oxygen saturation dropped to lower than 80% when she was in the sitting position. She had no patent foramen ovale or other intracardiac shunts. She showed gradual improvement and was discharged under home oxygen therapy 28 days after admission. Conclusions: This report highlights the importance of continuous bedside monitoring of pulse oximetry during positional changes, even if it is stable at rest, in patients with moderate to severe COVID-19.