Parenteral nutrition

Parenteral nutrition (PN) is the feeding of specialist nutritional products to a person intravenously, bypassing the usual process of eating and digestion. The products are made by specialist pharmaceutical compounding companies and are considered to be the highest risk pharmaceutical preparations available as the products cannot undergo any form of terminal sterilization. The person receives highly complex nutritional formulae that contain nutrients such as glucose, salts, amino acids, lipids and added vitamins and dietary minerals. It is called total parenteral nutrition (TPN) or total nutrient admixture (TNA) when no significant nutrition is obtained by other routes, and partial parenteral nutrition (PPN) when nutrition is also partially enteric. It may be called peripheral parenteral nutrition (PPN) when administered through vein access in a limb rather than through a central vein as central venous nutrition (CVN). Parenteral nutrition (PN) is the feeding of specialist nutritional products to a person intravenously, bypassing the usual process of eating and digestion. The products are made by specialist pharmaceutical compounding companies and are considered to be the highest risk pharmaceutical preparations available as the products cannot undergo any form of terminal sterilization. The person receives highly complex nutritional formulae that contain nutrients such as glucose, salts, amino acids, lipids and added vitamins and dietary minerals. It is called total parenteral nutrition (TPN) or total nutrient admixture (TNA) when no significant nutrition is obtained by other routes, and partial parenteral nutrition (PPN) when nutrition is also partially enteric. It may be called peripheral parenteral nutrition (PPN) when administered through vein access in a limb rather than through a central vein as central venous nutrition (CVN). Total parenteral nutrition (TPN) is provided when the gastrointestinal tract is nonfunctional because of an interruption in its continuity (it is blocked, or has a leak – a fistula) or because its absorptive capacity is impaired. It has been used for comatose patients, although enteral feeding is usually preferable, and less prone to complications. Parenteral nutrition is used to prevent malnutrition in patients who are unable to obtain adequate nutrients by oral or enteral routes. The Society of Critical Care Medicine (SCCM) and American Society for Parenteral and Enteral Nutrition recommends waiting until hospital day number seven. Absolute indications for TPN: TPN may be the only feasible option for providing nutrition to patients who do not have a functioning gastrointestinal tract or who have disorders requiring complete bowel rest, including bowel obstruction, short bowel syndrome, gastroschisis, prolonged diarrhea regardless of its cause, very severe Crohn's disease or ulcerative colitis, and certain pediatric GI disorders including congenital GI anomalies and necrotizing enterocolitis. There are physical, physiological, or mental differences in the geriatric population that could potentially lead to poor nutrient intake that would require them to have nutrition therapy. Patients that require nutrition therapy but have contraindications for or cannot tolerate enteral nutrition are appropriate candidates for parenteral nutrition. In the geriatric population, it is indicated if oral or enteral nutrition is impossible for 3 days or when oral or nutrition is likely insufficient for more than 7 to 10 days. While there are no complications of parenteral nutrition specific to the geriatric population, complications are more prevalent in this population due to increased comorbidities. Patients who are diagnosed with cancer, whether as outpatient undergoing treatment or hospitalized, are at a greater risk of malnutrition and cachexia. Cancer-related malnutrition can be attributed to the decrease in food intake, increase in the need for energy, and the alteration of metabolism. Patients should be assessed early on in their cancer treatment for any nutritional risk, such as by taking routine weights and BMI. Parenteral nutrition is indicated in cancer patients when it is not possible to access the digestive tract or if the tract is ineffective. In advanced cancer patients, the use of PN should be discussed in context of the risks and benefits, such as if the approximate survival rate is longer than 3 months and if PN would be expected to greatly improve the patients' quality of life. Short-term PN may be used if a person's digestive system has shut down (for instance by peritonitis), and they are at a low enough weight to cause concerns about nutrition during an extended hospital stay. Long-term PN is occasionally used to treat people suffering the extended consequences of an accident, surgery, or digestive disorder. PN has extended the life of children born with nonexistent or severely deformed organs. Approximately 40,000 people use TPN at home in the United States, and because TPN requires 10–16 hours to be administered, daily life can be affected. Although daily lifestyle can be changed, most patients agree that these changes are better than staying at the hospital. Many different types of pumps exist to limit the time the patient is “hooked up”. Usually a backpack pump is used, allowing for mobility. The time required to be connected to the IV is dependent on the situation of each patient; some require once a day, or five days a week. It is important for patients to avoid as much TPN-related change as possible in their lifestyles. This allows for the best possible mental health situation; constantly being held down can lead to resentment and depression. Physical activity is also highly encouraged, but patients must avoid contact sports (equipment damage) and swimming (infection). Many teens find it difficult to live with TPN due to issues regarding body image and not being able to participate in activities and events.