Hepatopulmonary Syndrome: A Brief Review

Abstract

Hepatopulmonary syndrome (HPS) is a pulmonary complication of liver disease characterized by arterial hypoxemia. Mechanisms related to this event are diffusion-perfusion flaw, ventilationperfusion (V/Q) mismatch, and direct arteriovenous shunts. Diagnosis of HPS is based on the presence of liver disease or portal hypertension, increased alveolar-arterial (A-a) PO 2 , and intrapulmonary vascular dilatations (IPVD). Lung transplantation (LT) remains the most effective therapy for HPS. In spite of its poor prognosis, we could improve the quality of life and survival rate of patients.

Molecular mechanisms of hepatopulmonary syndrome

“…Today the term "hepatopulmonary syndrome" (HPS) describes deficiency of arterial oxygenation caused by dilatation of intrapulmonary vessels associated with liver disease [2][3][4][5]. A classification of the severity of HPS based on oxygenation abnormalities has been proposed [4] (table 1).…”

Pulmonary Complications of Liver Cirrhosis: A Concise Review

“…Hepatopulmonary syndrome (HPS) is first described in 1977 by Kennedy and Knudson [1] and defined as a defect in arterial oxygenation caused by the presence of intrapulmonary vascular dilatation (IVPD) in the context of portal hypertension [2] (Figure 2). The estimated prevalence of HPS in liver cirrhosis is 4-32% [3]. In patients who were accessed for LT, the prevalence of HPS is approximately 10-30% [4].…”

“…Most patients with HPS present with dyspnea, orthopnea, platypnea, cyanosis, spider naevi, and finger clubbing [3,7]. Platypnoea or orthodeoxia is defined as the presence of shortness of breath (dyspnoea) that worsens while sitting or standing and relieved by lying down.…”

“…The pathogenesis of HPS is still unclear but the hallmark is thought to be due to intrapulmonary vasodilatation (IVPD), especially at the level of pre-capillary and capillary vasodilation [7]. IVPD is mediated by a number of endogenous vasoactive molecules, mainly endothelin-1 (ET-1) and nitric oxide (NO) [3,9]. Portal hypertension increased the production…”

“…Monsel et al reported the use of ECMO in preparation of LT in patients with refractory hypoxemia caused by a combination of acute respiratory distress syndrome (ARDS) and HPS [21]. The preliminary data showed that ECMO allowed the performance of successful LT by controlling gas exchange [3]. Auzinger et al also reported the successful case of using ECMO for severe refractory hypoxemia after LT in HPS patients [20].…”