Platypnea-Orthodeoxia Syndrome: Case Report With Interatrial Shunting

Abstract

SESSION TITLE: Fellow Case Report Poster - Pulmonary Physiology SESSION TYPE: Affiliate Case Report Poster PRESENTED ON: Tuesday, October 25, 2016 at 01:30 PM - 02:30 PM INTRODUCTION: Platypnea- orthodeoxia syndrome (POS) is a rare condition that is characterized by both dyspnea (platypnea) and arterial desaturation (orthodeoxia) in the upright position which resolves with recumbency. This syndrome can be categorized by etiology, which includes intracardiac shunting, pulmonary shunting, ventilation-perfusion mismatch, and disorders such as pericarditis, emphysema, and pneumonectomy. CASE PRESENTATION: 69 year old Caucasian female with metastatic cholangiocarcinoma to lungs and bone s/p whipple and stereotactic body radiation therapy that was admitted for acute blood loss anemia secondary to grade II bleeding esophageal varices. Patient had an episode of SVT, which was treated with adenosine and converted to sinus tachycardia thereafter. Patient subsequently developed acute asymptomatic hypoxia to 65% on room air that improved with non-rebreather facemask to 95%. ABG was consistent with primary respiratory alkalosis and concurrent metabolic acidosis. EKG was obtained that showed RH strain but sinus tachycardia. CTA was negative for PE but an echocardiogram with bubble study revealed right to left interatrial shunt consistent with a patent foramen ovale. Over the next few days, in an attempt to wean the patient off the oxygen, it was noted that the patient would desaturate to 70-75% while being on 5L nasal canula in the upright position but resolve to 95-97% in the recumbent position. DISCUSSION: Due to the rarity of POS, cases often are under diagnosed or entirely missed. For diagnostic purposes, two components are required which include the presence of “an interatrial shunt, such as a PFO, atrial septal defect, or fenestrated atrial septal aneurysm, or intrapulmonary shunting” and secondly a functional factor that “promotes abnormal shunting when the patient rises from a recumbent to an upright position.” Blood gas analysis are often helpful during the changes in positions however, cardiac catherization remains the gold standard which would demonstrate a mismatch in oxygen saturation between the pulmonary vein and the aorta. CONCLUSIONS: POS should be suspected when an individual has normal arterial saturation in the supine position with an abrupt desaturation in the upright position. Identification and correction of the shunting or mismatch often allows complete resolution of POS. Our patient was not a candidate for surgical intervention and palliative comfort measures were implemented. Reference #1: Stanislav Henkin, Sara Negrotto, Peter Pollak, Michael Cullen, D. Fearghas O'Cochlain, R. Scott Wright: Platypnea- Orthodeoxia Syndrome: Diagnostic challenge and the Importance of Heightened Clinical Suspicion. Tex heart Inst J 2015; 42 (5) Reference #2: Guerin P, Lambert V, Godart F, Legendre A, Petit J, Bourlon F, et al. Transcatheter closure of patent foramen ovale in patients with platypnea-orthodeoxia: results of a multicentric French registry. Cardiovasc Interventional Radiol 2005;28 (2) Reference #3: “Platypnea-orthodeoxia syndrome”- uptodate.com DISCLOSURE: The following authors have nothing to disclose: Arman Murabia No Product/Research Disclosure Information