Clinical predictors and characteristics of patients with chronic liver disease and intrapulmonary shunts

Intrapulmonary shunting (IPS) is a well-described phenomenon in chronic liver disease but its significance is not known.

The study was undertaken to enhance our understanding of the characteristics and prevalence of IPS.

We retrospectively studied 204 consecutive patients with end-stage chronic liver disease who underwent a dobutamine stress echocardiogram, along with a saline contrast bubble study, as part of their pretransplant evaluation.

Intrapulmonary shunting of any degree was present in 56.4% of patients. Patients with IPS were more likely to report alcohol use and less likely to have diabetes mellitus. Patients in Child-Pugh classification C were more likely to have IPS than those with classification A or B. The resting room air PaO2 levels were significantly lower in patients with grade 3-4 IPS than in those with grade 1-2. Elevated estimated pulmonary systolic pressure on echocardiography was more prevalent in patients with than in those without IPS.

A majority of patients with end-stage chronic liver disease undergoing transplant evaluation have IPS. There are important baseline differences between patients with and without IPS. The presence of IPS is associated with increased severity of chronic liver disease. Further study is required to define the prognostic significance of IPS and its impact on future liver transplantation.