Answer to Question 1
TPN is nutrition administered entirely by a route other than the gastrointestinal tract, usually through a central line.
Answer to Question 2
Bilirubin is a byproduct of hemoglobin breakdown. Lysed red cells (hemolysis) release hemoglobin into the blood stream. Hemoglobin is very quickly converted to bilirubin while still in the bloodstream. If hemolysis is severe, bilirubin will accumulate faster than the liver can clear it.