A Case of Platypnea-Orthodeoxia Syndrome Following COVID-19 Pneumonia Treated in a Convalescent Rehabilitation Ward.

Kaizu R, Maruyama H, Tanaka N, Takahashi H, Kigawa H. A Case of Platypnea-Orthodeoxia Syndrome Following COVID-19 Pneumonia Treated in a Convalescent Rehabilitation Ward. Jpn J Compr Rehabil Sci 2026; 17: 46-52. Platypnea-orthodeoxia syndrome (POS), characterized by worsening hypoxemia associated with postural changes, has been reported as a complication following pneumonia due to coronavirus disease 2019 (COVID-19). In most cases, POS improves during the acute phase. We report a case in which POS was diagnosed in a convalescent rehabilitation ward, with symptoms persisting for more than 100 days, ultimately enabling discharge to home. The patient was a 76-year-old man who, despite receiving acute-phase treatment for COVID-19 pneumonia, continued to exhibit marked oxygen desaturation and dyspnea in the sitting and standing positions, resulting in difficulty with mobilization. Following admission to the convalescent rehabilitation ward, decreases in SpO₂ and arterial partial pressure of oxygen associated with postural changes were confirmed, leading to a diagnosis of POS. Rehabilitation therapy was administered in short, high-frequency sessions, focusing on low-load sitting training and instruction on breathing techniques, while adjusting oxygen supplementation to facilitate mobilization. In addition, activities of daily living (ADL) training were initiated with early consideration of home oxygen therapy. As a result, sitting tolerance and ADL improved, and the patient was successfully discharged home with home oxygen therapy. POS may persist even in patients admitted to a convalescent rehabilitation ward. Even in cases where oxygen desaturation occurs with postural changes, appropriate adjustment of oxygen supplementation combined with short-duration, high-frequency mobilization may contribute to improvements in ADL and facilitate discharge to home.