Pulmonary complications of hepatic diseases

Abstract

Severe chronic liver disease (CLD) may result from portal hypertension, hepatocellular failure or the combination of both. Some of these patients may develop pulmonary complications independent from any pulmonary pathology that they may have. Among them the hepatopulmonary syndrome (HPS), portopulmonary hypertension (PPH) and hepatic hydrothorax (HH) are described in detail in this literature review. HPS is encountered in approximately 15% to 30% of the patients and its presence is associated with increase in mortality and also requires liver transplantation in many cases. PPH has been reported among 4%-8% of the patient with CLD who have undergone liver transplantation. The HH is another entity, which has the prevalence rate of 5% to 6% and is associated in the absence of cardiopulmonary disease. These clinical syndromes occur in similar pathophysiologic environments. Most treatment modalities work as temporizing measures. The ultimate treatment of choice is liver transplant. This clinical review provides basic concepts; pathophysiology and clinical presentation that will allow the clinician to better understand these potentially life-threatening complications. This article will review up-to-date information on the pathophysiology, clinical features and the treatment of the pulmonary complications among liver disease patients.

Keywords: Cirrhosis; Hepatic hydrothorax; Hepatocellular failure; Hepatopulmonary syndrome; Intrapulmonary shunting; Portopulmonary hypertension.

Figure 1

Pathophysiology of the hepatopulmonary syndrome and portopulmonary hypertension. TNF α: Tumoral necrosis factor alpha; ET_B: Endothelin type B; iNOS: Inducible nitric oxide synthase; HO-1: Heme oxygenase 1; VEGF: Vascular endothelial growth factor; eNOS: Endothelial nitric oxide synthase; CO: Carbon monoxide; NO: Nitric oxide.