[Parenteral nutrition: indications and techniques]

Parenteral nutrition corrects for or prevents malnutrition in patients with acute or chronic bowel disease. Whether acute (a few days to a few weeks) or chronic (a few weeks to several years), there are two pathophysiological mechanisms of bowel disease leading to malnutrition: motricity disorders and defective absorption. Total parenteral nutrition has to be prescribed in three situations: occlusive intestinal stenosis, pseudo-obstruction with complete food intolerance, clinically or endoscopically severe colitis. The indication for total parenteral nutrition to allow the intestine to "rest" is indicated in case of digestive fistulae with a high flow and for inflammatory bowel disease (Crohn's disease, irradiated bowel disease). In other cases, parenteral nutrition can be used as a complement to poorly tolerated or quantitatively insufficient oral or enteral nutrition to maintain the patient's nutritional status or correct for malnutrition. Peripheral (<3 weeks) or central (>3 weeks) parenteral nutrition, like all types of nutritional support, must be complete and conducted according to a rigorous written protocol specific for each indication, particularly acute versus chronic intestinal disease, in order to avoid iatrogenic and metabolic risks. This goal can be best achieved by developing a nutritional team within each hospital. Two other important goals are to enhance the efficacy of the nutritional support and to avoid inappropriate prescriptions, notably for parenteral administration. Such an approach allows a better risk/benefit ratio evaluated with nutritional standards. These are the prerequisites for nutritional therapy to be recognized as a major discipline in medicine.