Standard Polymeric Formulas are the most widely used sources of EN. They are available in a wide variety of formats that generally meet the nutritional requirements of a normal, healthy person. Carbohydrates provide most of the energy. The proteins (from casein, whey, or soy) are intact and require normal pancreatic enzyme function for digestion and absorption. These products are isotonic or nearly so, and provide from 1000-2000 kcal and 50-70-g protein/L. Additional formula types include Polymeric Formulas with Fiber, Elemental and Semi-elemental Formulas, and Immune-enhancing Formulas, Protein-enriched Formulas, as well as disease-specific formulas used in pts with diabetic, hepatic, renal, or pulmonary disease.

After elevation of the head of the bed and confirmation of correct tube placement, continuous infusion is initiated using a half-strength diet at a rate of 25-50 mL/h. This can be advanced to full strength as tolerated to meet the energy target. The major risks of enteral tube feeding are aspiration, diarrhea, electrolyte imbalance, glucose intolerance, sinusitis, and esophagitis.