What is Included in Enteral Feeding?

Over 500,000 Americans receive enteral nutrition each year, which is a method of delivering nutrients directly to the gastrointestinal tract via a feeding tube. Knowing what is included in enteral feeding is vital for patients, caregivers, and healthcare providers to ensure adequate nutrition and prevent complications.

Quick Summary

Enteral feeding includes three primary components: the feeding formula, the access device or tube, and the delivery system. The formula provides essential macronutrients, micronutrients, and hydration, while the tubes direct the feed into the stomach or small intestine. The delivery system controls the rate and schedule of feeding to match patient needs.

Key Points

• Enteral Formula: A special liquid food mixture containing all necessary macronutrients (protein, carbs, fats) and micronutrients (vitamins, minerals).

• Access Devices (Tubes): A pathway for the formula, including nasoenteral tubes for short-term use and surgically placed gastrostomy or jejunostomy tubes for long-term feeding.

• Delivery Systems: Methods for administering the feed, such as continuous feeding via a pump or intermittent/bolus feeding via a syringe or gravity.

• Water Flushes: Used regularly to prevent tube clogging and ensure the patient remains properly hydrated.

• Medication Supplies: Specialized syringes and procedures are required for administering medications safely through the feeding tube, avoiding compatibility issues.

• Site Care Equipment: For surgically placed tubes, dressings and cleaning supplies are needed to prevent infection and irritation.

Essential Components of Enteral Feeding

Enteral Formulas: The Nutrient Mix

The most critical component of enteral feeding is the liquid formula, which is designed to provide complete nutrition. These formulas are carefully balanced to meet a patient's specific dietary requirements and can be tailored for various medical conditions. There are several types of formulas, each with a unique composition.

• Standard (Polymeric) Formulas: These contain intact proteins, carbohydrates, and fats, and are suitable for patients with normal or near-normal digestive function. They often include added fiber and come in different caloric densities to suit fluid requirements.
• Elemental and Semi-Elemental Formulas: These are used for patients with compromised gastrointestinal function or malabsorption issues. The nutrients, particularly the protein, are partially or fully hydrolyzed (pre-digested) to make them easier to absorb.
• Specialty Formulas: Tailored for specific diseases, these formulas address conditions like diabetes (lower carbohydrates), renal disease (adjusted electrolytes), or immune compromise (immune-modulating nutrients like arginine and omega-3s).
• Blenderized Formulas: Made from real food ingredients, these can be either commercially prepared or homemade. They are often chosen for long-term feeding and may improve GI tolerance for some individuals.

Access Devices: The Pathway for Nutrition

An enteral access device, or feeding tube, is necessary to deliver the formula to the GI tract. The type of tube depends on the expected duration of feeding and the patient's medical condition.

• Nasoenteral Tubes: These are for short-term feeding, typically less than four to six weeks.
  • Nasogastric (NG) tube: Inserted through the nose, down the esophagus, and into the stomach.
  • Nasoduodenal (ND) or Nasojejunal (NJ) tube: Placed into the small intestine, used for patients at high risk of aspiration or with impaired gastric emptying.
• Ostomy Tubes: These are surgically placed for long-term feeding, lasting longer than four to six weeks.
  • Gastrostomy (G-tube) or PEG tube: Inserted directly into the stomach through the abdominal wall.
  • Jejunostomy (J-tube) or PEJ tube: Inserted into the jejunum (small intestine) through the abdominal wall, bypassing the stomach.
  • Gastrojejunostomy (GJ-tube): A tube with ports in both the stomach and the jejunum.

Delivery Systems: Regulating the Flow

The delivery system dictates how the formula is administered and can significantly impact patient tolerance and safety.

• Continuous Feeding: Formula is delivered at a slow, constant rate over 8 to 24 hours via a feeding pump. This is ideal for patients who cannot tolerate large volumes at once, such as those with GI intolerance or those receiving post-pyloric feeding.
• Intermittent Feeding: Administered several times a day over a shorter period (e.g., 30-60 minutes), often using a pump or gravity. This method mimics regular meal patterns and allows for greater mobility during the day.
• Bolus Feeding: Delivers a larger volume of formula over a short period (5-15 minutes) using a syringe. It is suitable for stable patients with good gastric function and is more convenient for active individuals.
• Gravity Feeding: Similar to bolus feeding but uses an elevated bag to control the flow rate with gravity instead of a pump.

Comparison of Enteral Tube Types

Feature	Nasogastric (NG) Tube	Gastrostomy (PEG) Tube
Duration of Use	Short-term (less than 4-6 weeks)	Long-term (more than 4-6 weeks)
Insertion Method	Bedside insertion, non-invasive	Endoscopic procedure, invasive
Common Indications	Dysphagia, altered consciousness, short-term need	Long-term nutritional support, permanent swallowing issues
Patient Comfort	Potential for nasal/throat irritation and discomfort	More cosmetically acceptable and comfortable long-term
Risk of Displacement	Higher risk of accidental dislodgment	Less risk of displacement once fully healed
Risk of Aspiration	Can have a moderate risk, especially with impaired reflexes	Generally lower risk of aspiration compared to NG tubes
Maintenance	Regular site checks for irritation	Requires stoma site care and monitoring for infection

Additional Considerations and Accessories

Besides the main components, several other items are integral to a complete and safe enteral feeding regimen.

• Water Flushes: Regular flushing with water is critical to prevent the tube from clogging and to maintain proper hydration.
• Medication Administration: Specific techniques and accessories, such as ENFit syringes, are used to safely administer liquid medications through the feeding tube, often requiring flushing before and after.
• Feeding Syringes: These are used for bolus feeding and for flushing the tube. They are designed with the new, safer ENFit connector to prevent misconnections with intravenous lines.
• Feeding Bags and Tubing: Used with pumps for continuous or intermittent feeding, these items connect the formula container to the feeding tube.
• Feeding Pumps: Deliver the formula at a precise, controlled rate, which is especially important for continuous or jejunal feeding.
• Site Care Supplies: For ostomy tubes, supplies like cleaning swabs, dressings, and fixation devices are needed to prevent infection and irritation at the insertion site.
• Monitoring Equipment: Includes tools for assessing gastric residual volume (GRV), though guidelines for this practice are evolving.

Conclusion

In summary, enteral feeding is a comprehensive system designed to deliver nutrition directly to a patient’s functional gastrointestinal tract. What is included in enteral feeding encompasses the nutrient-rich formulas, the specific access device chosen for the patient, and the delivery method, such as continuous or bolus feeding. A successful enteral feeding plan also depends on the correct use of ancillary equipment and adherence to proper administration techniques, all guided by a healthcare team. The choice of which components to include is highly individualized, based on the patient's specific nutritional needs, medical condition, and expected duration of therapy. A thorough understanding of each element is essential for optimizing patient outcomes, promoting comfort, and ensuring safety throughout the process.

Further Reading

For more detailed clinical recommendations on enteral nutrition, refer to the resources from the American Society for Parenteral and Enteral Nutrition (ASPEN).

Resource Title	Website URL
American Society for Parenteral and Enteral Nutrition	https://nutritioncare.org/about/what-we-do/nutrition-support/what-is-enteral-nutrition/

Frequently Asked Questions

What is the primary difference between enteral and parenteral feeding?

The main difference is the route of administration. Enteral feeding uses a functioning gastrointestinal tract, delivering nutrients via a tube. Parenteral feeding bypasses the GI tract entirely, providing nutrients directly into the bloodstream through an intravenous line.

How is the right enteral formula selected for a patient?

Formula selection is based on a patient's individual nutritional needs, digestive function, and medical condition. Options range from standard formulas with intact nutrients for normal digestion to specialized formulas with pre-digested nutrients for malabsorption.

What is the purpose of flushing an enteral feeding tube?

Flushing the tube with water is essential to prevent blockages, ensure medication is properly delivered, and provide the patient with adequate hydration.

What types of access devices are used for enteral feeding?

Access devices include temporary nasoenteral tubes (inserted through the nose) and permanent ostomy tubes (surgically placed into the stomach or small intestine).

Can regular food be used for enteral feeding?

Yes, some commercially available or homemade formulas are blenderized using real food ingredients. However, this requires a larger bore tube to prevent clogging and needs careful preparation to ensure nutritional completeness and safety.

What are the common methods of delivering enteral feeds?

The most common delivery methods are continuous feeding (slow, steady drip via a pump), intermittent feeding (scheduled intervals), and bolus feeding (large, quick volumes via a syringe).

Is enteral feeding used for critically ill patients?

Yes, enteral feeding is the preferred method for nutritional support in most critically ill patients who have a functioning GI tract. It is associated with fewer complications compared to parenteral nutrition.