RESUMEN
Hepatopulmonary syndrome (HPS) is characterized by intrapulmonary microvasculature dilatation that causes intrapulmonary shunting and leads to a gas exchange abnormality in the presence of liver diseases, which is the most common cause of respiratory insufficiency in these patients. HPS doubles the risk of death, and liver transplantation (LT) is the only curative therapeutic option so it should be considered in patients with severe HPS, with excellent survival rates post-LT. However, pretransplant Pao2 <45 mm Hg has been associated with an increase in post-transplant morbidity and mortality, but it does not imply a contraindication for LT. The resolution of HPS usually occurs within 6 months post-LT, but it can take 1 year. Portopulmonary hypertension (PoPH) is defined as pulmonary arterial hypertension (PAH) that develops in the setting of portal hypertension with or without liver disease in the absence of other causes of PAH. The prevalence of PoPH is 5% to 10% among liver transplant (LT) candidates. The impact of LT on PoPH is unpredictable. Therefore, despite conferring a high morbidity and mortality, PoPH itself is not an indication for liver transplantation. It may be considered a contraindication for LT in severe cases.