Clinical controversies surrounding the diagnosis and treatment of hepatopulmonary syndrome.

Hepatopulmonary syndrome (HPS) is a clinical syndrome which complicates liver disease but remains poorly defined. To date there is no consensus on the definition of hypoxemia or the best diagnostic test that provides evidence of intrapulmonary shunting. Furthermore, it is reasonable to question whether the role of intrapulmonary shunting has been overplayed in the etiology of HPS and if echocardiographic intrapulmonary shunts could simply be nonspecific markers of the hyperdynamic circulation of liver disease. These inquiries lend support to theories that HPS is primarily a manifestation of profound pulmonary vascular autoregulatory failure that occurs in predisposed patients. Because there is little experience with clinical interventions for HPS other than liver transplantation, there are few accepted, efficacious therapeutic options for these patients. Because liver transplantation remains the only treatment known to effectively ''treat'' HPS, many medical communities have increased the priority of HPS patients over others who are waiting for life saving organs. Until there is further evidence that effectively identifies patients with HPS and that predicts outcomes, the preferential allocation of organs to patients with suspected HPS may unjustly cause the death of others waiting for transplantation.