Introduction

A middle-aged patient with a history of smoking and alcoholic liver cirrhosis was screened for liver transplantation. He had dyspnea on exertion. The EKG and chest X-ray revealed no abnormalities. Pulmonary function tests showed moderate obstruction. Arterial blood gas analysis revealed hypoxemia (saturation 89%) without significant orthodeoxia. On a 6 min walk test, saturation decreased to 82%. The AA-gradient was elevated (8.4 kPa). CT did not show any arteriovenous communications. Intrapulmonary shunting measured by conventional oxygen method and confirmed by radionuclide imaging was 19%. Transthoracic echocardiography demonstrated normal left and right ventricular size and function, mitral …