Case report: We report the case of an eighty-year-old man admitted for profound asthenia present for about a year and dyspnea mainly upon awakening. His medical history included arterial hypertension, smoking habit, colon neoplasm surgery and initial cognitive decline. On physical examination, the patient exhibited marked desaturation, mild tachypnea, cyanosis of the lips and digital clubbing. No other significant clinical findings at the cardiac, pulmonary, abdominal and neurological levels. Laboratory tests showed only polycythemia; echocardiography and pulmonary CT-angiography were normal. Arterial blood gas analysis showed a severe respiratory failure type 1, so the patient was admitted to the intensive care unit where high-flow nasal cannula (HFNC) was applied with limited signs of improvement. Subsequently, the patient was transferred to our Internal Medicine ward. A more thorough medical history revealed exacerbation of symptoms in the upright position. Placing the patient in a supine position we observed a significant increase in peripheral saturation values. This detail suggested us the presence of platypnea-orthodeoxia syndrome, documented by arterial blood gas analysis. Among the main causes of this syndrome, intracardiac or extracardiac shunts should be considered. A bubble study and a transoesophageal echocardiography showed an Atrial Septal Aneurysm with a large Patent Foramen Ovale. Conclusions: Platypnea-orthodeoxia syndrome is rare, and as such, the challenge lies not in diagnosis but in initially considering it as a diagnostic possibility, also in elderly patients.
A Tue, study studied this question.