Tube Feedings: Enteral Nutrition

1. Indications for Enteral Nutrition: the preferred route - "If the gut works, use it"


  • Mechanical GI tract dysfunction/disorders - may have normal digestive & absorptive function with an oral/mechanical/physiological obstruction
  • Facial/jaw injuries, head & neck CA, swallowing disorders, obstruction of the upper GI tract, GI tract fistulas, short bowel syndrome (feed beyond the obstruction/fistula)
  • Metabolic GI tract dysfunction - may have impaired ability to digest & absorb nutrients
  • Pancreatitis, infalmmatory bowel disease, radiation enteritis, chemotherapy
  • Hypermetabolic conditions - may have increased energy & protein requirements that cannot be met with regular oral intake
  • Major burns, trauma, sepsis, post-operative recovery following surgery

2. Contraindication for Enteral Therapy: GI tract not working

  • Intractable vomiting
  • Intestinal obstruction
  • Upper GI tract hemorrhaging
  • Severe, intractable diarrhea
  • Severe, acute pancreatitis
  • Expected need less than 5-10 days

3. Routes:

  • Short-term: Nasogastric, Nasoduodenal, Nasojejunal
  • Long-term
    Gastrostomy & Jejunostomy (surgically placed) and PEG - percutaneous-esophago-gastrostomy & PEJ - percutaneous-esophago-jejunostomy (endoscopically placed)
Location of enteral feeding tubes

4. Tubes

Tube size: Consider viscosity of formula; select the smallest appropriate size for patient comfort. 8 French can generally be used for commercial formulas while the patient will need a 10-14 French for blenderized formulas.

Tube length: Depends on tube placement, with a 30" length for nasogastric feeding and 43" for nasoduodenal & nasojejunal feedings.

5. Selecting the formula: based on patient need

Consider each of the following factors:

  • How well the GI tract is functioning and its capacity
  • Underlying disease conditions
  • Patient tolerance

Enteral Formula Categories

Category Subcategory Characteristics Indications
Polymeric Standard
Similar to average diet Normal digestion
High nitrogen Protein>15% of total kcal
  • Catabolism
  • Wound healing
Caloric dense 2 kcal/ml
  • Fluid restriction
  • Volume intolerance
  • Electrolyte imbalance
Fiber containing
Fiber 5-15 g/L Regulation of bowel function
Monomeric Partially hydrolyzed

One or more nutrients are hydrolyzed.
Composition varies.

Impaired digestive and absorptive capacity
Peptide based
Disease- Specific Renal Less protein, low electrolyte content Renal failure
Hepatic High branched chain amino acids (valine, isoleucine and leucine, which are known as the stress amino acids), low aromatic amino acids (phenylalanine; tyrosine; tryptophan), low electrolyte content Hepatic encephalopathy
Higher % of calories from fat instead of carbohydrates ARDS
Diabetic Low carbohydrates Diabetes mellitus
Immune-enhancing Arginine, glutamine, omega-3 fatty acid, antioxidants
  • Metabolic stress
  • Immune dysfunction

from (Note: N170 students responsible for Nutritional concepts and Enteral Nutrition ONLY)

6. Administration of feedings

  • Bolus
  • Intermittent
  • Continuous
  • Noncritically ill patient
  • Home TF
  • Rehabilitation patient
  • Easy to administer
  • Inexpensive
  • Short administration time (usually 15 minutes)
Highest risk of aspiration, N/V, abdominal pain and distention, and diarrhea
  • Noncritically ill patient
  • Home TF
  • Rehabilitation patient
  • Flexibility in feeding schedule
  • Inexpensive
  • Feeding over shorter time allows patient more free time
  • Higher risk of aspiration, N/V, abdominal pain and distention, and diarrhea
  • May require formula with more calories and protein
  • Initiation of tube feedings
  • Critically ill patient
  • Small bowel feeding
  • Intolerance of intermittent or bolus
  • Pump assisted
  • Minimizes risk of high gastric residuals and aspiration
  • Minimizes risk of metabolic abnormalities
  • Restricts ambulation
  • Infused over 24 hours/day
  • Increased cost (need pump)


7. Feedings started:

  • In the past tube feedings that were hyperosmolar were diluted ½ strength - current recommendations are to leave the formula full strength and begin at a lower volume until tolerance is determined.
  • Full strength if isotonic - DO NOT DILUTE ISOTONIC FORMULAS!
  • Tube feeding is progressed until assessed nutrition goal reached
  • If TF is diluted, do not advance concentration and rate at the same time

8. Tolerance

  • Check gastric residuals
  • Diarrhea
  • Constipation
  • Bloating and excess gas production

9. Sanitation

  • bag and tubing is changed every 24 hours, but check your hospital protocol
  • formula is administered at room temperature

TF should not be started until an X-ray shows the tube is in the proper place, then formula can be started

Head of bed (HOB) must be elevated at least 30° at all times.