Total parenteral nutrition (TPN) gives a person liquid nutrition (such as protein, carbohydrates, and fats) through a tube (catheter) that is inserted into a vein. In a newborn, the tube may be inserted into the umbilical cord artery.

TPN places nutrients needed for growth and tissue repair directly into the blood, bypassing the digestive tract completely.

A person's blood sugar and blood chemicals (such as electrolytes) are monitored while he or she receives this type of nourishment.