Stroke and Respiratory Failure: Mind the Shunt!

When stroke patients present with respiratory failure, the first thought that clinicians have is that it is probably related to aspiration pneumonia. However, other causes should be considered, such as intracardiac or intrapulmonary shunts, that could present with paradoxical embolism. Paradoxical embolism is a rare entity defined by the occurrence of a venous thrombotic event associated with a systemic arterial embolism. Frequently, paradoxical embolism presents with platypnoea-orthodeoxia syndrome. Platypnoea-orthodeoxia syndrome is uncommon and is characterized by dyspnoea and hypoxaemia induced by orthostatic position, where symptoms and oxygenation are relieved by recumbency. The authors report a case of a patient who presented with an ischaemic stroke and progression to platypnoea-orthodeoxia syndrome with documentation of simultaneous pulmonary embolism and pulmonary arteriovenous malformations. LEARNING POINTS: There are other causes to explain simultaneous presentation of stroke and respiratory failure, which should be kept in mind. The association between arterial and venous thrombosis; be aware of paradoxical embolism and search for intracardiac or intrapulmonary shunts. Platypnoea-orthodeoxia syndrome is characterized by dyspnoea and hypoxaemia induced by orthostatic position and relieved by recumbency; it is a red flag to think of an intracardiac or intrapulmonary shunt.