Parenteral nutrition-associated liver disease in adult and pediatric patients.

There are essentially 3 types of hepatobiliary disorders associated with parenteral nutrition (PN) therapy: steatosis, cholestasis, and gallbladder sludge/stones. Reported prevalence rates of PN-associated liver disease (PNALD) vary greatly, and there are distinct differences between adult and pediatric patients. Various etiologic factors have been evaluated for significance in contributing to PNALD, including enteral feeding history, septic events, bacterial overgrowth, length of intestinal resection, and prematurity/low birth weight. Etiologic factors specifically related to the PN formulation or nutrient intake have also been evaluated, including excessive calorie intake, dextrose-to-lipid ratio, amino acid dose, taurine deficiency, IV fat emulsion (IVFE) dose, carnitine deficiency, choline deficiency, and continuous vs cyclic infusion. Minor increases in serum aminotransferase concentrations are relatively common in patients receiving PN therapy and generally require no intervention. The primary indicator of cholestasis is a serum conjugated bilirubin >2 mg/dL. When a patient receiving PN develops liver complications, it is necessary to rule out all treatable causes and minimize other risk factors. All potential hepatotoxic medications and herbal supplements should be eliminated. Modifications to the PN regimen that may be helpful include reduction of calories, reduction of IVFE dose to <1 g/kg/d, supplementation of taurine in the infant, and use of cyclic infusion. Initiation of even small amounts of enteral nutrition and use of ursodiol may be beneficial in stimulating bile flow. In the long-term PN patient with severe and progressive liver disease, intestinal or liver transplantation may be the only remaining treatment option.