Cirrhosis can be complicated by refractory hypoxemia due to high rates of blood flow through the lung, resulting in ventilation-perfusion mismatch. Fat embolism syndrome, in which fat droplets are deposited in the pulmonary capillary bed. Shunting
Shunting refers to blood that bypasses the pulmonary circulation, meaning that the blood does not receive oxygen from the alveoli. In general, a shunt may be within the heart or lungs, and cannot be corrected by administering oxygen alone. Shunting may occur in normal states:

Anatomic shunting, occurring via the bronchial circulation, which provides blood to the tissues of the lung. Shunting also occurs by the smallest cardiac veins, which empty directly into the left ventricle. Physiological shunts, occur due to the effect of gravity. The highest concentration of blood in the pulmonary circulation occurs in the bases of the pulmonary tree compared to the highest pressure of gas in the apexes of the lungs. Alveoli may not be ventilated in shallow breathing.Shunting may also occur in disease states:

Acute respiratory distress syndrome (ARDS). Alveolar collapse, which can increase the amount of physiological shunting, may be managed through a combination of increasing oxygenation as well as positive pressure to recruit collapsed alveoli. Pathological shunts such as patent ductus arteriosus, patent foramen ovale, and atrial septal defects or ventricular septal defects. These states are when blood from the right side of the heart moves straight to the left side, without first passing through the lungs. This is known as a right-to-left shunt, which is often congenital in origin.
A ventricular outflow tract obstruction is one type of congenital heart defect in which either the right or left ventricular outflow tract is blocked or obstructed. These obstructions represent a spectrum of disorders. Right side
A right ventricular outflow tract obstruction (RVOTO) may be due to a defect in the pulmonic valve, the supravalvar region, the infundibulum, or the pulmonary artery. Pulmonary atresia
Pulmonary valve stenosis
Hypoplastic right heart syndrome
Tetralogy of Fallot

Left side
A left ventricular outflow tract obstruction (LVOTO) may be due to a defect in the aortic valve, or a defect located at the subvalvar or supravalvar level. Aortic valve stenosis
Supravalvar aortic stenosis
Coarctation of the aorta
Hypoplastic left heart syndrome


== References ==