Parenteral Nutrition Associated Liver Toxicity: Prevention, Diagnosis and Management

Long-term parenteral nutrition (PN) treatment is limited by parenteral nutrition–associated liver disease (PNALD), which is characterized initially by intrahepatic cholestasis, typically defined as a direct bilirubin greater than 2 mg/dL in the absence of other causes of liver disease. PNALD is typically less common and less severe and progresses more slowly in older children and adults than in infants. The etiology of PNALD is multifactorial. Key factors include immature liver function, sepsis, and a lack of enteral nutrition. Additionally, nearly every component of PN has been attributed to or exacerbated hepatotoxicity. PN preparations must be carefully individualized and monitored to minimize hepatotoxicity from its various components. Although many hepatotoxic components or imbalances have been recognized, soybean oil–based lipid emulsions continue to be widely used as they are the only lipid emulsions currently approved for PN by the Food and Drug Administration. Fish oil–based lipid emulsions have been shown to reverse PNALD, with an associated decrease in mortality. As such, fish oil therapy should be considered early once biochemical cholestasis is detected in PN-dependent patients. Studies investigating the use of novel lipid emulsions for prevention and treatment of PNALD are ongoing. This review contains 5 figures, 5 tables, and 114 references.