Rapid resolution of refractory hypoxemia and vascular spiders following liver transplantation

ABSTRACT The syndrome of platypnea-orthodeoxia is a rare disorder characterized by dyspnea and oxygen desaturation in the upright position that improve when supine. Excluding cardiac etiologies, the most common causes are intrapulmonary right-to-left shunt due to either abnormally dilated pulmonary blood vessels in hepatopulmonary syndrome (HPS) or pulmonary arteriovenous malformations in hereditary hemorrhagic telangiectasia (HHT). Both conditions can cause cutaneous telangiectasia, and both are associated with pulmonary vascular abnormalities identifiable on chest computed tomographic (CT) imaging. Differentiating between them can be challenging, as there is overlap in their clinical and radiographic manifestations. We present a patient with severe refractory hypoxemia, platypnea, orthodeoxia and cutaneous telangiectasia whose subtle clinical and laboratory findings did not initially suggest significant liver disease. Also, refractory hypoxemia in response to a high fraction of inspired oxygen strongly suggested anatomical right-to-left shunt. Thus, the alternative diagnosis of diffuse microvascular pulmonary arteriovenous malformations as a rare manifestation of HHT was entertained. The patient was referred for possible lung transplantation. Further investigations revealed chronic liver disease, confirming the diagnosis of HPS. Liver transplantation resulted in rapid resolution of the severe refractory hypoxemia and disappearance of the cutaneous telangiectasia. Nine months post liver transplant, chest CT imaging showed marked improvement in the pulmonary vascular abnormalities. This patient’s clinical presentation and work-up illustrate: (i) the relevance of subtle clinical and chest CT findings to the differential diagnosis of intrapulmonary right-to-left shunt; and (ii) the importance of a thorough knowledge of the mechanisms of hypoxemia to understanding the pathophysiology of HPS.