Harrison's Internal Medicine Part 4. Nutrition Chapter 73. Enteral and Parenteral Nutrition Therapy Enteral and Parenteral Nutrition Therapy: Introduction The ability to provide specialized nutritional support (SNS) represents a major advance in medical therapy. Nutritional support, via either enteral or parenteral routes, is used in two main settings: (1) to provide adequate nutritional intake during the recuperative phase of illness or injury, when the patient's ability to ingest or absorb nutrients is impaired, and (2) to support the patient during the systemic response to inflammation, injury, or infection during an extended critical illness. SNS is also used in patients with. | Chapter 073. Enteral and Parenteral Nutrition Part 1 Harrison s Internal Medicine Part 4. Nutrition Chapter 73. Enteral and Parenteral Nutrition Therapy Enteral and Parenteral Nutrition Therapy Introduction The ability to provide specialized nutritional support SNS represents a major advance in medical therapy. Nutritional support via either enteral or parenteral routes is used in two main settings 1 to provide adequate nutritional intake during the recuperative phase of illness or injury when the patient s ability to ingest or absorb nutrients is impaired and 2 to support the patient during the systemic response to inflammation injury or infection during an extended critical illness. SNS is also used in patients with permanent loss of intestinal length or function. In addition an increasing number of elderly patients living in nursing homes and chronic care facilities receive enteral feeding usually as a consequence of inadequate nutritional intake. Enteral refers to feeding via a tube placed into the gut to deliver liquid formulas containing all essential nutrients. Parenteral refers to the infusion of complete nutrient solutions into the bloodstream via a peripheral vein or more commonly by central venous access to meet nutritional needs. Enteral feeding is generally the preferred route because of benefits derived from maintaining the digestive absorptive and immunologic barrier functions of the gastrointestinal tract. Small-bore pliable tubes have largely replaced large-bore rubber tubes making placement easier and more acceptable to patients. Infusion pumps have also improved the delivery of nutrient solutions. For short-term use enteral tubes can be placed via the nose into the stomach duodenum or jejunum. For long-term use these sites can be accessed through the abdominal wall using endoscopic radiologic or surgical procedures. Intestinal tolerance of tube feeding may be limited during acute illness by gastric retention or diarrhea. Parenteral feeding has .
