When the gastrointestinal tract is not able to digest and absorb food, the necessary elements of nutrition can be artificially provided via the blood. Intravenous feedings are known as total parenteral nutrition (TPN). Essential nutrient needs are met by formula infusion into a large vein in the chest area. Life can be supported for decades with intravenous nutrition. However, since this is not how the body naturally uses nutrients, there are some common side effects.
The benefit of intravenous nutrition is that it supports life for those who have an illness preventing them from eating. People who have complications from Crohn’s disease, ulcerative colitis, colon cancer or other conditions may be left without enough functioning intestine to absorb nutrition. One hundred percent of nutritional needs can be met through carefully controlled intravenous feeding. People who require intravenous nutrition support can live at home and function in fairly normal lives. They do need to be attentive to the daily infusion of a sterile formula under a sterile technique. Blood tests are frequently monitored and special attention must be paid to any physical symptoms.
Mechanical Side Effects
Merck reports 5 to10 percent of patients have complications from line placement, which may include lung collapse. Up to 50 percent have sepsis, an infection in the bloodstream, and infection at the entry site of the port is also not uncommon. A clinical review in The Consultant Pharmacist on monitoring TPN in the elderly reports other catheter complications, such as air bubbles, clogging or even breaking. These all require the immediate attention of a physician.
Metabolic Side Effects
Because nutrients are infusing directly into the bloodstream, as opposed to naturally through the digestive tract, careful monitoring of blood levels is required. Glucose, triglycerides, and certain mineral blood levels can rise or fall dramatically, causing serious problems. Merck reports liver dysfunction is most common when TPN is first initiated, but is serious and must be treated. The Oley Foundation, an organization to support people living at home on nutrition support provides a reference chart with recommended actions for abnormal blood sugar ranges, dehydration and other metabolic complications.
A Last Resort
For people without a functioning gastrointestinal tract, intravenous nutrition can be life saving. If some degree of function is still present, however, the gut should be used as much as possible. Feeding directly into the digestive tract promotes intestinal health and preserves cell integrity. TPN brings more expense, more potential for health complications, and more need for daily monitoring. When intravenous feeding is the only option, the benefits outweigh the risks by maintaining a reliable means of nutritional support that is safe when administered under careful conditions.