Why's total perenteral nutrition hard on the liver?

Carbs: If the amount of carb (sugars) in TPN is too high, it can cause fatty buildup and inflammation in the liver. This usually goes away when the carbs are decreased or if the TPN is stopped.

Depends on age: Tpn is certainly toxic to the liver over time and eventually will result in liver cirrhosis from cholestatic disease. The exact etiology is unclear but the presence of lipids (fats) and the type of lipids in the TPN contributes to the problem. The immature liver of an infant or child develops complications faster than an adult liver. We try to lower lipid levels in TPN to minimize liver damage.

TPN.: TPN avoids the digestive system altogether as the nutrients enter the blood directly. That's why the lining of the digestive tract, unused, can break down while on TPN, too.

Protein versus fat: some attribute the protein, some attribute the fat to irritating the liver, and causing inflammation. That is why people who receive TPN are monitored for their liver function tests.