23 December 2025
: Case report 
Platypnea-Orthodeoxia Syndrome Associated With a Right-to-Left Cardiac Shunt Detected by Lung Perfusion Scintigraphy
Challenging differential diagnosis, Rare disease
Yusuke Nakano
ABCDEFG 1,2*, Hirohiko Ando CDE 1, Akinori Satake DE 3, Reiji Goto DE 1, Kentaro Mukai DE 1, Tetsuya Amano CDE 1
DOI: 10.12659/AJCR.949642
Am J Case Rep 2025; 26:e949642
Table 1 Admission laboratory data: supine hypoxemia with mild hepatic dysfunction and polycythemia.
| pH | 7.45 | |
| pCO | 34.9 | Torr |
| pO | 53.7 | Torr |
| HCO | 23.5 | mmol/L |
| SAT | 87.0 | % |
| A-aDO | 52.7 | Torr |
| WBCs | 5900 | /μL |
| RBCs | 5.04 | ×10/μL |
| Hb | 16.1 | g/dL |
| Ht | 48.3 | % |
| Plt | 19.2 | ×10/μL |
| BUN | 36.3 | mg/dL |
| Cre | 0.82 | mg/dL |
| eGFR | 54 | mL/min/1.73 m |
| AST | 47 | U/L |
| ALT | 41 | U/L |
| pCO – partial pressure of carbon dioxide; pO – partial pressure of oxygen; HCO– – bicarbonate; SAT, oxygen saturation; A-aDO – alveolar-arterial oxygen gradient; WBCs – white blood cells; RBCs – red blood cells; Hb – hemoglobin; Ht – hematocrit; Plt – platelet count; BUN – blood urea nitrogen; eGFR – estimated glomerular filtration rate; AST – aspartate aminotransferase; ALT – alanine aminotransferase. | ||