Liver function values in adults receiving total parenteral nutrition

A retrospective review was made of results of conventional liver function tests in adult patients who received fat-free total parenteral nutrition (TPN) for two weeks or longer and who did not have other obvious causes for liver function abnormalities. A "meaningful" increase (greater than or equal 50% increase above baseline pre-TPN value) in SGOT levels was noted in 68% of patients, in alkaline phosphatase levels in 54%, and in serum bilirubin levels in 21% of patients. The median peak values for SGOT, alkaline phosphatase, and bilirubin were 3-, 1.9-, and 0.25-fold above the upper limit of normal, respectively. The median time interval of peak increase for each of the three tests was between 9 and 12 days after TPN was started. Liver biopsy specimens from four patients, taken when liver function values were abnormal, showed pronounced steatosis in three patients and mild periportal cholestasis in the fourth patient. The cause(s) of the elevated liver values is unknown, but possibilities include cellular damage, such as steatosis, and an "overshoot" of enzymes when starved patients are refed.