total parenteral nutrition (TPN), the administration of a nutritionally adequate hypertonic solution consisting of glucose, protein hydrolysates, minerals, and vitamins through an indwelling catheter into the superior vena cava or other main vein. Fat is also provided in a three-in-one solution or “piggy-backed.” The high rate of blood flow results in rapid dilution of the solution, and full nutritional requirements can be met indefinitely. The procedure is used in prolonged coma, severe uncontrolled malabsorption, extensive burns, GI fistulas, and other conditions in which feeding by mouth cannot provide adequate amounts of the essential nutrients. In infants and children it is used when feeding via the GI tract is impossible, inadequate, or hazardous, such as in chronic intestinal obstruction from peritoneal sepsis or adhesions, inadequate intestinal length, or chronic nonremitting severe diarrhea. The hyperalimentation solution is infused through conventional tubing with an IV filter attached to remove any contaminates. In adults the catheter is placed directly into the subclavian vein and threaded through the right innominate vein into the superior vena cava. In infants and small children the catheter is usually threaded to the central venous location by way of the jugular vein, which is entered through a subcutaneous tunnel beneath the scalp. Strict asepsis must be maintained because infection is a grave and present danger of this therapy. Also called hyperalimentation, intravenous alimentation, parenteral hyperalimentation, total parenteral alimentation.
