Saline Contrast Echocardiography in Patients With Hepatopulmonary Syndrome Awaiting Liver Transplantation

Background Patients with hepatopulmonary syndrome (HPS) with end-stage liver disease (ESLD) have higher cardiorespiratory mortality than those without. The aims of this study were to determine whether echocardiography could distinguish patients with ESLD with and without HPS and whether the diagnosis of HPS by contrast echocardiography (CE) was altered by the performance of the test in a supine or standing position. Methods Subjects were recruited prospectively from patients with end-stage liver disease undergoing assessment for liver transplantation. Hepatopulmonary syndrome was diagnosed on the basis of arterial blood gas analysis, lung function testing and agitated saline contrast echocardiography in the absence of primary cardiac or pulmonary disease. Bubble contrast injections were performed supine or standing in a randomised order and read by a blinded observer. Results CE showed late right-to-left shunting in 13 of 50 consecutive patients with cirrhosis (26%). Eight patients (16%) had definite diagnoses of HPS. CE in the standing position consistently increased both the number and the size of shunts compared with supine injection. CE detected intrapulmonary shunting before a change in arterial blood gases. Standard echocardiographic parameters did not distinguish between those with and without HPS. Conclusion This study suggests that screening for HPS in patients with advanced cirrhosis should be done using CE with patients in the upright position.