Manual of Clinical Nutrition

Enteral Nutrition Support Therapy for Adults

Manual of Clinical Nutrition Management B- 37 Copyright © 2013 Compass Group, Inc.

The order specifies:

 product, either by name or as “Standard Tube Feeding,” according to hospital protocol
 volume, rate, and timing, including the initial volume and rate, as well as the progression and goal volume and
rate^ (At a standard dilution of 1.0 kcal/mL, the volume will be roughly equal to the number of kilocalories
specified.)
 administration and monitoring, following either the facility’s standard procedures or individualized
orders, including the administration of extra water to flush the tube or meet fluid requirements

See Section III: Clinical Nutrition Management, Enteral Nutrition: Management of Complications

Routes of Access for Enteral Tube Feeding (4)
The type and route of feeding tube should depend on the patient’s needs and the route that optimizes
nutrient delivery (stomach or small bowel) for disease management. The smallest tube possible should be
used for patient comfort (4), and correct placement of the feeding tube should be confirmed by X-ray prior to
use (4). When the anticipated need for enteral nutrition exceeds 4 to 6 weeks, a more permanent enteral
access device is indicated (4).

There are several types of feeding tube placements:

 Orogastric: The feeding tube is inserted through the mouth, with the tip resting in the stomach.
 Nasogastric: The feeding tube is inserted through the nose, with the tip resting in the stomach.
 Nasoduodenal: The feeding tube is inserted through the nose, with the tip resting in the duodenum.
 Nasojejunal: The feeding tube is inserted through the nose, with the tip resting in the jejunum.
 Esophagostomy: The feeding tube is inserted through a surgical opening in the neck and passed through
the esophagus, with the tip resting in the stomach.
 Gastrostomy: The feeding tube is inserted through the abdominal wall into the stomach via
percutaneous endoscopic guidance or surgical placement (surgical “open” gastrostomy).
 Jejunostomy: The feeding tube is inserted through the abdominal wall into the jejunum via percutaneous
endoscopic guidance or surgical placement (surgical “open” jejunostomy).

Enteral Formula: Categories and Selection
Choosing the most appropriate tube-feeding formula is critical for achieving nutritional goals. Formulas
should be selected based on digestibility/availability of nutrients, nutritional adequacy, viscosity, osmolality,
ease of use, and cost (4). In addition, the nutritional status of the patient, including electrolyte balance,
digestive and absorptive capacity, disease state, renal function, medical or drug therapy, and possible routes
of enteral infusion should be considered (4). Enteral formulations are considered medical foods by the Food
and Drug Administration (FDA); therefore, their labels can make “structure and function” claims without the
approval of the FDA (4). Limited evidence is available regarding the efficacy and outcomes associated with the
use of specialized enteral formulations (3,4).

Enteral formulas can be classified as standard (or polymeric), elemental, or semi-elemental. Standard
formulas include synthetic formulas and blenderized formulas. Specialized enteral formulas include disease-
specific formulas and nutrient-modified formulas. Additionally, individual modular components that can
supplement the formula are available (15). Most enteral formulations provide adequate amounts of vitamins
and minerals to meet the Reference Daily Intakes when provided in volumes of 1,000 mL to 1,500 mL daily
(16). Enteral formulas contain a large amount of water; their water content generally ranges from 70% to 85%
(15). It is important to be aware of patients with potential food allergies when prescribing an enteral formula.
Enteral formulations may contain milk, soy, corn, or egg products, all of which are common allergens (15).
Most enteral formulations are lactose free and gluten free (15).

Standard or polymeric formulas: Standard or polymeric formulas must be digested into dipeptides and
tripeptides, free amino acids, and simple sugars in the small bowel. Polymeric formulas require adequate
digestive and absorptive capability and are indicated in patients with normal or near-normal gastrointestinal
function. There are two basic types of polymeric formulas, synthetic formulas and blenderized formulas.
Synthetic formulas are the most commonly used formulas due to their safety and feasibility in an institutional
setting (4).

Synthetic formulas are used for standard tube feedings. Their energy content ranges from 1.0 to 2.0
kcal/mL. The protein content provides 12% to 20% of total energy and consists of intact protein, generally