Expression And Location Of Heme Oxygenase-1 In The Lung Of Experimental Rats With Hepatopulmonary Syndrome

Cirrhosis, portal hypertension, and even acute liver failure may result in a complex change in the pulmonary arterial bed. As a result, there are at least two clinically important and very distinct pulmonary vascular consequences: hepatopulmonary syndrome (HPS) and porto- pulmonary hypertension (PPH). These entities are pathophysiologically distinct in that hepatopulmonary syndrome is characterized by vasodilatation and portopulmonary hypertension results from vasoconstriction. The clinical implications are also quite dissimilar in the most dramatic presentations: gas exchange impairment in HPS (severe hypoxemia) and hemodynamic compromise in PPH (right heart failure). Fluckiger, in 1884, gave the first description of an interaction between the liver and the lung. The first description of the pathophysiology of the syndrome was given by Rydell and Hoffbauer.Arterial hypoxemia associated with liver disease ismulti-factorial and not only a consequence of HPS. Indeed,other reasons for hypoxemia as measured by PaO₂ or thealveolar-arterial gradient are more frequent. Severe hypoxemia(PaO₂<50mmHg) , however, is likely because of HPS. A...