Manual of Clinical Nutrition Management B- 33 Copyright © 2013 Compass Group, Inc.
SPECIALIZED NUTRITION SUPPORT THERAPY
Description
Specialized nutrition support therapy is the provision of nutrients orally, enterally, or parenterally with
therapeutic intent (1). The preferred route for patients who cannot meet their nutritional needs through
voluntary oral intake is enteral nutrition, the nonvolitional delivery of nutrients by tube into the gastrointestinal
tract through a feeding tube, catheter, or stoma (1-4). Parenteral nutrition is the administration of nutrients
intravenously (1). The modality of nutrition therapy selected should permit the delivery of required nutrients by
the safest, most cost-effective route for the patient.
The goals of nutrition support therapy in both well-nourished and malnourished critically ill patients are to
prevent the depletion of lean body mass, promote acute phase and whole body protein synthesis, and prevent
physiologic deterioration (2). Traditionally, nutrition support in critically ill patients was regarded as adjunctive
care designed to provide energy to support the patient during the stress response (4). Recently, these goals have
become more focused on nutrition therapy, specifically attempting to attenuate the metabolic response to stress,
prevent oxidative cellular injury, and favorably modulate the immune response (4).
The following section is a brief outline of nutritional management with these two modalities of nutrition
support therapy. More detailed information related to specialized nutrition support therapy for critically ill
patients can be found in the cited literature and evidence-based guidelines (2-4).
Indications (1-4)
Evidence-based guidelines for managing critically ill patients support early nutrition intervention. Enteral
nutrition is recommended over parenteral nutrition in critically ill patients who are hemodynamically stable
and have a functioning gastrointestinal tract. Enteral nutrition along with adequate fluid resuscitation should be
initiated 24 to 48 hours after injury or admission to the intensive care unit (Grade I)* (2-4). In the critically ill
patient, early enteral nutrition is associated with a reduction in infectious complications (Grade I) (2) and may
reduce the length of hospitalization (2). Patients who receive enteral nutrition experience lower rates of septic
morbidity and fewer infectious complications than patients who receive parenteral nutrition (Grade I) (2-5). In a
large sample of patients with traumatic brain injury, early nutrition intervention was associated with improved
medical outcomes and reduced mortality (6). It is advised that patients with traumatic brain injury should
receive some form of nutrition support within 24 to 48 hours after injury to support their increased energy
needs (5). In surgical patients and critically ill patients, enteral feedings should be provided without waiting for
the resumption of flatus or bowel movements (5).
According to guidelines from the American Society for Parenteral and Enteral Nutrition and the Society of
Critical Care Medicine, if enteral nutrition is not feasible or available for the first 7 days following the intensive
care unit admission of a critically ill patient who was previously healthy with no evidence of protein-calorie
malnutrition, no nutrition support therapy should be provided (4). Refer to Section II for guidelines to identify
patients who are malnourished or may become malnourished. The use of parenteral nutrition should be
reserved and initiated only after the first 7 days of hospitalization (4). However, if there is evidence of protein-
calorie malnutrition on admission and enteral nutrition is not feasible, it is appropriate to initiate parenteral
nutrition as soon as possible following adequate resuscitation (4). If a patient is expected to undergo major
upper gastrointestinal surgery and enteral nutrition is not feasible, parenteral nutrition should be provided
under the specific conditions described below (4):
If the patient is malnourished, parenteral nutrition should be initiated 5 to 7 days preoperatively and be
continued into the postoperative period (4).
Should enteral nutrition not be feasible after surgery, the initiation of parenteral nutrition should be
delayed for 5 to 7 days (4).
Parenteral nutrition should be initiated only if the duration of therapy is anticipated to be at least 7 days.
Parenteral nutrition therapy provided for a duration of less than 5 to 7 days would be expected to have no
beneficial effect and may result in an increased risk to the patient (4).
Contraindications
Specialized nutrition therapy is usually not indicated for: malnourished patients who are eating adequate
amounts to meet their estimated nutrient requirements; well-nourished patients who are anticipated to resume
adequate oral intake within 7 days; and patients whose prognosis does not warrant aggressive nutritional care