Patients who are malnourished or at significant risk for becoming malnourished should receive specialized nutrition support. Early enteral nutrition should be initiated within 24-48 hours of admission in critically ill patients with high nutritional risk who are unable to maintain volitional intake.6 In the absence of preexisting malnutrition, nutritional support should be provided for patients with inadequate oral intake for 7-14 days or for those in whom inadequate oral intake is expected over the same time period.7
How should nutritional support be administered?
Dietary modification and supplementation
In patients who can tolerate an oral diet, dietary modifications may be made in order to facilitate the provision of essential nutrients in a well-tolerated form. Modifications may include adjusting the consistency of foods, energy value of foods, types of nutrients consumed, and number and frequency of meals.8 Commercial meal replacement beverages are widely used to support a standard oral diet, but there is no data to support their routine use.7
Enteral nutrition (EN) is the method of choice for administering nutrition support. Contraindications to enteral feeding include diffuse peritonitis, intestinal obstruction, and gastrointestinal ischemia.9 The potential advantages of EN over parenteral nutrition (PN) include decreased infection rate, decreased total complications, and shorter length of stay, but there has been no observed difference in mortality. EN is also suggested to have nonnutritional benefits related to providing luminal nutrients – these include maintaining gut integrity, beneficial immune responses, and favorable metabolic responses that help maintain euglycemia and enhance more physiologic fuel utilization.4