A 71 year-old woman with alcoholic cirrhosis presented to the emergency room and referred effort dyspnea for the last six months. She had a past medical history of ex-smoker (10 pack/year), glaucoma and hypothyroidism. She had been abstinent from alcohol for one year and showed no admissions for edematous-ascites syndrome, esophageal varices or spontaneous bacterial peritonitis. Her Model for End-Stage Liver Disease (MELD) score at the time of presentation to our center was 17.On physical exam, her breath sounds were clear and did not show signs of fluid overload. Cyanosis, clubbing or platypnea were not present, however orthodeoxia was detected: SaO2 of 93% (0.21) in supine position and SaO2 of 89% in upright position. Computer tomography scans showed ground glass areas with and thickening of interlobular septa. Laboratory evaluation showed: hematocrit = 41%, hemoglobin = 14.5 g/dl, platelet count = 83000/mm3, total bilirubin = 2.7 g/dl, alkaline phosphatase =118 U/l, serum albumine = 4.1 g/ dl, aspartate aminotransferase = 30UI/l and alanine aminotransferase = 43UI/l. HIV serology was negative and her immunological profile inconsistent with collagen diseases.Pulmonary function, respiratory gas exchange and ventilationperfusion relationships were studied. Both forced spirometry results and lung volumes by plethysmography were normal. A severely reduced DLCO (37%) after adequate correction for anaemia was detected (Table 1). Arterial blood gas (ABG) on room air revealed a pH of 7.43, partial pressure of oxygen (PaO2) was 57.7 mmHg, partial pressure of dioxide (PaCO2) was 30 mmHg, and an alveolar arterial gradient of 43 mmHg. Contrast enhanced transesophageal echocardiography Abbreviations