The neonatal liver: Part III: Pathophysiology of liver dysfunction.

The liver, the largest organ in the body, is critical to a number of key metabolic functions. Its also plays an important role in removing the waste products of metabolism (particularly ammonia) and in detoxifying drugs and other substances such as endogenous hormones and steroid compounds. In addition, the liver plays a major role in the production of clotting factors, plasma proteins, bile salts, and bilirubin. Many neonates display signs of hepatic dysfunction such as hyperbilirubinemia, hepatomegaly, or elevated liver enzymes. These often occur secondary to systemic illness, such as sepsis or hypoxic injury, or following the use of drugs or parenteral nutrition to treat other problems. Although rare, primary liver disease does occur in neonates and must be recognized promptly, with treatment initiated in a timely manner to prevent unnecessary sequelae. This article, the third in a series on the liver, examines causes of liver dysfunction in neonates, beginning with an overview of jaundice and hepatomegaly and moving to a discussion of specific diseases.