Print | Back
Overview of parenteral and enteral nutrition
Debora Duro, MD, MS
Sharon Collier, RD, MEd
Christopher Duggan, MD, MPH
J Thomas LaMont, MD
Timothy O Lipman, MD
Kathleen J Motil, MD, PhD
Alison G Hoppin, MD
Last literature review version19.2: mayo 2011 | This topic last updated: septiembre 9, 2010 (More)
INTRODUCTION — Advances in the field of clinical nutrition continue to be brought to the marketplace with great speed and variety. As a result, physicians caring for patients with nutritional deficits, critical illness, or primary gastrointestinal diseases are faced with what can be a bewildering array of choices of enteral andparenteral formulations. Furthermore, as nutritional components increasingly include properties formerly ascribed solely to medications, the term "nutritional pharmacology" has been coined to more accurately describe these nutrients .
This topic review will focus on two major issues related to artificial nutrition support (as defined by nutrition provided via enteral tube feedings or via theparenteral route): indications for its use and guidelines for choosing appropriate formulations of these nutrients.
INDICATIONS FOR ARTIFICIAL NUTRITION SUPPORT — A number of indications for artificial nutrition support have been suggested by clinical experience and controlled trials. For some patient groups, including those with severe chronic intestinal failure or neonates who cannot be fed bymouth because of necrotizing enterocolitis, the utility of parenteral nutrition is obvious and cannot ethically be tested through randomized trials. For many other patient groups with less extreme nutritional needs, randomized trials can and should be performed, but the current evidence base is limited.
The results of clinical trials have not always been consistent. Several meta-analyses haveraised concerns about poor study design and high-bias risk with many of these studies, and results are likely applicable only to specific patient populations [2,3]. The following conclusions can be drawn. Many of the recommendations for adult patients are summarized in greater detail in an American Gastroenterological Association (AGA) technical review for parenteral nutrition :
* Weak evidencesupports the use of enteral nutrition in perioperative patients with chronic liver disease, critically ill patients, low birthweight infants (as trophic feeding), and malnourished geriatric patients .
* For geriatric patients with advanced dementia, there is no evidence that enteral nutrition improves quality of life or physical function, reduces pressure sores, or prolongs survival .It may increase the risk of developing pneumonia due to aspiration. (See "Medical care of the nursing home patient in the United States", section on 'Nutrition'.)
* There is inadequate evidence to support the use of short-term enteral nutrition to adult patients recovering from hip fractures [5,7].
* In adult patients who have dysphagia after a stroke but who are not malnourished, thepotential adverse effects of using enteral nutrition outweigh the potential benefits within the first week of hospitalization. If the dysphagia persists, these patients will require enteral nutrition .
* Parenteral nutrition should not routinely be given to adult patients undergoing cancer chemotherapy or radiation therapy because it may increase the risk of complications such ascatheter-associated infections and thrombosis [4,8].
* In adult patients with newly diagnosed tuberculosis and wasting, supplemental enteral nutrition may increase lean mass and improve physical function compared to standard nutritional counseling alone .
* Parenteral nutrition may improve clinical outcomes in patients with short bowel syndrome and in adult postoperative patients with esophageal or...