Hepatopulmonary Syndrome (HPS) is a condition characterized by pulmonary vascular dilation, abnormal oxygenation with a stirred pulse, and hypoxemia occurring in liver disease. This syndrome was first reported by Rydell Hoffbauer in 1956, and the concept of HPS was proposed by Kennedy and Knudson in 1977. Hepatopulmonary Syndrome is primarily seen in patients with severe cirrhosis (Child-Pugh class C), often accompanied by massive ascites, clubbing of fingers, portal hypertension, and insufficient oxygen supply with a stirred pulse. PaO2 is often <10 kPa.

bubble_chart Etiology

The pathogenesis of hepatopulmonary syndrome is related to decreased affinity of oxyhemoglobin, pulmonary capillary dilation caused by vasodilatory factors such as prostaglandins, intrapulmonary (arteriovenous and portopulmonary venous) shunting, impaired oxygen diffusion between alveoli and capillaries, ventilation/perfusion mismatch, and compression from conditions like ascites. The main pathological changes include pulmonary vascular dilation, pulmonary circulatory disturbances, multiple anastomotic branches between peripheral pulmonary vessels and large hilar arteries and veins, allowing mixed venous blood to enter the pulmonary veins.

bubble_chart Clinical Manifestations

The main characteristics are difficulty breathing and cyanosis.

bubble_chart Diagnosis

In the diagnosis of chronic liver diseases, especially in patients with cirrhosis and massive ascites, severe hypoxemia (PaO2 < 6.7 kPa) should raise suspicion of this syndrome. A PaO2 < 10 kPa is a necessary condition for diagnosing HPS; orthodeoxia is a sensitive and specific indicator for diagnosing HPS.

bubble_chart Treatment Measures

In treatment, the priority should be given to addressing hypoxemia, which requires oxygen administration, such as via nasal cannula at 2–3 L/min. The efficacy of glucocorticoids, somatostatin, and prostaglandin inhibitors, among others, remains to be further studied and confirmed.