From the Guidelines
Total Parenteral Nutrition (TPN) can cause transaminitis, which is an elevation in liver enzymes (transaminases) such as ALT and AST, as a result of prolonged TPN use, usually after several weeks of administration. This complication is a significant concern in patients receiving long-term parenteral nutrition, with a reported occurrence of liver disease in both children and adults on TPN, at a frequency of between 15 and 85% 1. The liver dysfunction occurs because TPN bypasses normal digestive processes, leading to alterations in bile flow, accumulation of lipids in the liver, and potential inflammation.
Risk Factors and Prevention
Risk factors for TPN-associated transaminitis include excessive caloric intake (particularly from dextrose), lack of enteral stimulation, certain medication interactions, and pre-existing liver disease. To minimize this risk, healthcare providers should:
- Use cyclic TPN administration when possible
- Avoid overfeeding
- Ensure balanced macronutrient composition
- Add some enteral feeding if feasible
- Regularly monitor liver function tests 1.
Monitoring and Management
Early detection through routine liver enzyme monitoring allows for timely adjustments to the TPN formulation before significant liver damage occurs. It is also essential to monitor plasma or whole blood concentrations of manganese and copper, as impaired liver excretory function may lead to an accumulation of these elements 1.
Underlying Disease and Nutrition Regimen
The underlying disease, such as short bowel syndrome, and the nutrition regimen, including intravenous lipid intake, can also impact the development of chronic cholestasis and severe liver disease in patients on TPN 1. Supplementation with taurine in parenteral nutrition has been reported to ameliorate PN-associated cholestasis 1. Therefore, a comprehensive approach to managing TPN-associated transaminitis is crucial to prevent significant liver damage and improve patient outcomes.
From the Research
TPN and Transaminitis
- Total Parenteral Nutrition (TPN) can cause liver injury, including transaminitis, as evidenced by elevated liver enzymes such as alanine transaminase (ALT) and aspartate transaminase (AST) 2, 3, 4.
- The exact mechanism of TPN-induced liver injury is multifactorial and not fully understood, but it is thought to involve disruption of the normal enterohepatic circulation, gut bacterial permeation, and toxicity of the TPN solution itself 2, 5.
- Studies have shown that TPN can cause a range of liver abnormalities, including steatosis, cholestasis, and fibrosis, with infants being more susceptible to TPN-related hepatocellular injury 3.
- The type of lipid emulsion used in TPN may also play a role in liver injury, with some studies suggesting that certain types of lipid emulsions may be more toxic to the liver than others 5, 6.
- Clinical markers of liver injury, such as elevated liver enzymes, may not always predict the degree of hepatocellular injury or fibrosis, and serial biopsies may be necessary to monitor liver health in patients on TPN therapy 3.