Hepatopulmonary syndrome, an unusual cause of hypoxemia.

A six-year-old boy presented with cough, cyanosis and clubbing. Investigations revealed hypoxia (PaO2 53 mm Hg on room air) which was only partially correctable (PaO2 73 mm Hg) with 100% oxygen administered through a non re breathing face mask. Liver function tests showed elevated total bilirubin, and transaminases, liver biopsy confirmed chronic hepatitis and endoscopy showed grade three varices. A contrast enhanced echocardiography (bubble study) revealed pulmonary arterio-venous communication. A diagnosis of hepatopulmonary syndrome was made based on the triad of hypoxemia, liver disease and intra pulmonary vascular communications.