- Platypnea-orthodeoxia (P-O) syndrome is an under-diagnosed condition characterized by dyspnea and deoxygenation when changing from a recumbent to an upright position
- It is usually caused by increased right-to-left shunting of blood on assuming an upright position, with normal pressure in the right atrium
- It may also be caused by intrapulmonary shunting combined with extensive pulmonary lesions or severe V/Q mismatching
- ASD or PFO with position-dependent shunting, often in combination with one of the conditions below.
- Other Cardiac
— Pericardial effusion
— Constrictive pericarditis
— Aortic aneurysm
— Multiple pulmonary emboli
— Pulmonary emphysema
— Radiation-induced bronchial stenosis
— Hepatopulmonary syndrome
— Amiodarone toxicity of the lungs
— Pulmonary A-V communications
— PCP pnuemonia
— fat embolism syndrome
— Parkinson disease
— Bilateral thoracic sympathectomy
— Hepatic cirrhosis
- supine and upright PaO2 measurement
- tilt transesophageal echocardiogram with bubble study (<100% sensitive) – diagnosis of the shunt can be difficult
- look for other underlying causes
- Closure of the ASD or PFO
- Treat any associated condition
— A case associated with Parkinson’s disease was attributed to postural hypotension, and improved with fludrocortisone.
— A case associated with radiation-induced bronchial stenosis was relieved by bronchial dilation initially, and later by bronchial stenting.
— A case associated with bilateral thoracic sympathectomy (van Heerdon 2004) was treated initially with noradrenaline and almitrine.
References and Links
- 2005 Australian Short Course in Intensive Care Hanbook (pdf)
- Lee CH, Cheng ST. Shortness of breath while sitting up: hepatopulmonary syndrome. CMAJ. 2011 Jan 11;183(1):80. Epub 2010 Oct 12. Erratum in: CMAJ. 2011 Feb 22;183(3):349. PubMed PMID: 20940238; PubMed Central PMCID: PMC3017258.
- Ptaszek LM, Saldana F, Palacios IF, M Wu S. Platypnea-Orthodeoxia Syndrome in Two Previously Healthy Adults: A Case-based Review. Clin Med Cardiol. 2009 Apr 9;3:37-43. PubMed PMID: 20508765; PubMed Central PMCID: PMC2872575.
- Salvetti M, Zotti D, Bazza A, Paini A, Bertacchini F, Chiari E, Coletti G, Rosei EA, Muiesan ML. Platypnea and orthodeoxia in a patient with pulmonary embolism. Am J Emerg Med. 2013 Apr;31(4):760.e1-2. doi: 10.1016/j.ajem.2012.12.004. Epub 2013 Feb 4. PubMed PMID: 23380102.