TY - JOUR T1 - The hepatopulmonary syndrome: NO way out? JF - European Respiratory Journal JO - Eur Respir J SP - 661 LP - 662 DO - 10.1183/09031936.04.00028204 VL - 23 IS - 5 AU - A.T. Dinh-Xuan AU - R. Naeije Y1 - 2004/05/01 UR - http://erj.ersjournals.com/content/23/5/661.abstract N2 - “How diseases of the liver affect lung function?” is one of those puzzling questions that can turn obsessive for those who want to understand how two seemingly distinctive organs can interact and eventually lead to severe disorders 1, 2. The most common respiratory consequence of liver disease is hypoxaemia, which is often mild to moderate 3. Seldom severe hypoxaemia occurs when the arterial pressure of oxygen (Pa,O2) falls below 8 kPa (60 mmHg), heralding the occurrence of a condition known as the “hepatopulmonary syndrome” (HPS). HPS is characterised by a triad of conditions, namely: 1) advanced liver disease (with or without liver cirrhosis); 2) widespread intrapulmonary vasodilatation; and 3) alveolar-arterial oxygen gradient (PA‐a,O2) >2.6 kPa (20 mmHg) whilst breathing room air 2, 3. Clinical symptoms typically include shortness of breath, which may either worsen on standing (platypnoea) and/or be accompanied by a 10% fall in Pa,O2 (orthodeoxia). As with other lung disorders, hypoxaemia results from impaired gas exchange, which, in HPS, is particularly perturbed by excessive and widespread dilatation of intrapulmonary vessels. After decades of careful investigations, the underlying mechanisms linking altered gas exchange and pulmonary vasodilatation are now well delineated 2–4. Reduced tone causing vascular relaxation occurs at both ends of the capillary bed, i.e. affecting pre-capillary and post-capillary vessels. This … ER -