A physician considers several factors when deciding which feeding route to use. Of particular importance are the aspiration potential of the route of administration, and the expected duration of the enteral therapy.

When using feeding tubes, several schedules of administration may be considered, including continuous infusion, and intermittent infusion (also called bolus feedings).

The primary indication for nutritional therapy is inadequate protein and calorie intake. The choice of enteral versus parenteral support (also called TPN) is typically based on the gastrointestinal tract’s functionality, or lack thereof. “If the gut works, use it", is a common method for determining which administration route to use.

If the patient is eating, oral supplementation should be selected. If the patient cannot eat or cannot swallow adequately, or if oral supplementation is not successful, enteral feeding should be considered.

In 1987 the American Society of Enteral and Parenteral Nutrition (ASPEN) published guidelines for the use of enteral nutrition, which included the clinical settings in which enteral nutrition is helpful, the clinical settings in which it is of limited value, and the settings in which it is contraindicated. The guidelines are intended to be applied to patients who cannot ingest adequate amounts of nutrients orally but have properly functioning gastrointestinal tracts. 

Why use a pump instead of bolus feedings? Of the two feeding schedules mentioned earlier, continuous infusion requires the use of a pump to deliver formula at a constant rate over 24 hours. A major advantage to this mode of administration is a smaller osmotic load compared with intermittent feedings. This smaller osmotic load may decrease the likelihood of gastric intolerance and aspiration by improving gastric motility, as compared to bolus feedings. In addition, in a skilled nursing setting, continuous feedings are easier to use and more convenient and less exposed to error than the bolus feeding method.

Monitoring Nutritional Status

Patients receiving enteral nutrition need to be monitored for effectiveness. This is frequently the job of a registered dietitian.

A baseline weight should be taken along with regular weights throughout the therapy, intakes and outputs volume data, and routine laboratory screenings, including serum glucose and electrolyte levels and hematologic markers. The traditional indicator for protein metabolism has been serum albumin.[55]

There are about 60,000 patients receiving enteral nutrition support in the United States, and about 220,000 patients worldwide.[55] One-quarter to one-third of this group is 65 years or older, depending on the underlying diagnosis.

Geriatric enteral nutrition patients generally have good outcomes, but as a rule typically do not do as well as their younger counterparts; however, geriatrics have fewer therapy-related complications than children.[55]