Enteral nutrition generally refers to any method of feeding that uses the gastrointestinal (GI) tract to deliver part or all of a person’s caloric requirements. It can include:
Parenteral nutrition refers to the delivery of calories and nutrients into a vein. This could be as simple as carbohydrate calories delivered as simple sugar in an intravenous solution or all of the required nutrients could be delivered including carbohydrate, protein, fat, electrolytes (for example sodium and potassium), vitamins and trace elements (for example copper and zinc).
TPN is a way of supplying all the nutritional needs of the body by bypassing the digestive system and dripping nutrient solution directly into a vein. TPN is used when individuals cannot or should not get their nutrition through eating. TPN is used when the intestines are obstructed, when the small intestine is not absorbing nutrients properly, or a gastrointestinal fistula (abnormal connection) is present. It is also used when the bowels need to rest and not have any food passing through them.
TPN is also used for individuals with severe burns, multiple fractures, and in malnourished individuals to prepare them for major surgery, chemotherapy, or radiation treatment. Individuals with AIDS or widespread infection (sepsis) may also benefit from TPN. It is also used for patients who have gastroparesis and cannot digest food properly.