What is Enteral Nutrition?
In medical terminology, the official name for tube feeding is enteral nutrition (EN). The word “enteral” refers to the gastrointestinal (GI) tract, indicating that this method delivers nutrients directly into the gut. Unlike oral intake, which involves eating and swallowing, enteral nutrition uses a flexible tube to bypass the mouth and esophagus, ensuring that patients receive the necessary calories, protein, fluids, vitamins, and minerals.
Enteral nutrition is a cornerstone of supportive medical care for many conditions. It is preferred over other methods, like parenteral nutrition, because it is more physiological, less invasive, and generally carries a lower risk of serious infection and complications. By preserving the function of the gastrointestinal tract, enteral nutrition helps maintain gut integrity and immune function, which is critical for healing and overall health.
Indications for Enteral Feeding
Healthcare providers recommend enteral nutrition when a patient has a functional digestive system but cannot meet their nutritional goals orally. Common reasons for needing a feeding tube include:
- Neurological conditions: Stroke, amyotrophic lateral sclerosis (ALS), or other disorders that impair the ability to chew or swallow (dysphagia).
- Gastrointestinal issues: A narrowed esophagus, motility disorders, or conditions where nutrient absorption is a challenge.
- Head and neck cancers: Treatments like radiotherapy can make swallowing painful or difficult.
- Critical illness or injury: Conditions such as burns or severe illness increase metabolic needs beyond what can be consumed by mouth.
- Unconsciousness: Patients who are in a coma or have altered mental status cannot safely take food orally.
Types of Feeding Tubes
Feeding tubes are categorized by their insertion method and where they terminate in the GI tract. The choice of tube depends on the anticipated duration of feeding and the patient's medical condition.
Short-term access (less than 4–6 weeks):
- Nasogastric (NG) tube: Passed through the nose, down the esophagus, and into the stomach. It is suitable for temporary feeding needs and easy to insert at the bedside.
- Nasojejunal (NJ) or Nasoduodenal (ND) tube: Extended from the nose past the stomach into the small intestine. This is used for patients with impaired gastric emptying or a higher risk of aspiration.
Long-term access (more than 4–6 weeks):
- Gastrostomy (G-tube) / Percutaneous Endoscopic Gastrostomy (PEG) tube: Inserted directly into the stomach through a small incision in the abdominal wall. It is more comfortable and less visible for long-term use.
- Jejunostomy (J-tube) tube: Inserted into the jejunum (small intestine) through the abdominal wall, bypassing the stomach completely. It is used when feeding into the stomach is not feasible.
Enteral vs. Parenteral Nutrition: A Comparison
While both methods provide artificial nutritional support, enteral and parenteral nutrition are fundamentally different and used for distinct clinical scenarios.
| Feature | Enteral Nutrition | Parenteral Nutrition (TPN) |
|---|---|---|
| Delivery Route | Directly into the gastrointestinal (GI) tract via a tube. | Directly into the bloodstream via a vein, bypassing the GI tract. |
| GI Tract Function | Requires a functional GI tract. | Used when the GI tract is not functional or needs complete rest. |
| Cost | Generally less expensive. | Typically more expensive due to complex formulas and sterile preparation. |
| Infection Risk | Lower risk of systemic infection compared to TPN. | Higher risk of bloodstream infections due to direct venous access. |
| Immune Support | Helps preserve the gut mucosal barrier and immune system function. | Does not provide direct immune support via the gut, potentially increasing risk of complications. |
| Administration | Can be done via bolus, continuous, or cyclic feeding. | Administered continuously via a pump, often over 10-12 hours overnight. |
How Enteral Nutrition is Administered
The administration method of enteral nutrition depends on the tube type and the patient's tolerance.
- Bolus Feeding: A larger volume of formula is delivered over a short period using a syringe, typically during mealtimes. This is often used with G-tubes.
- Continuous Feeding: Formula is delivered slowly and continuously over 8 to 24 hours using an electronic pump. This is standard for intestinal feedings, which cannot tolerate large volumes at once.
- Cyclic Feeding: A variation of continuous feeding where the formula is infused over a shorter period, such as overnight, allowing the patient more freedom during the day.
Benefits and Risks of Enteral Feeding
Benefits
- Preserves Gut Function: Maintains the health and integrity of the GI tract, preventing the atrophy that can occur with disuse.
- Cost-Effective: Less expensive than other nutritional support methods, especially parenteral nutrition.
- Reduced Infection Risk: The natural barrier of the gut helps lower the risk of systemic infections.
- Nutrient Delivery: Allows for precise and complete nutrient delivery when oral intake is impossible.
Risks
While generally safe, enteral nutrition can have complications:
- Gastrointestinal Issues: Common side effects can include nausea, bloating, vomiting, diarrhea, or constipation.
- Aspiration Pneumonia: A serious risk where formula enters the lungs, most commonly with nasogastric tubes or if the patient is lying flat during feeding.
- Refeeding Syndrome: A potentially fatal electrolyte imbalance that can occur when severely malnourished patients are refed too quickly.
- Tube Complications: Issues such as tube blockage, dislodgement, or leakage at the insertion site.
Conclusion
Understanding what is the official name for tube feeding, enteral nutrition, is essential for comprehending this vital medical procedure. It is a preferred and highly effective method for providing necessary nutrients when oral intake is compromised but the digestive system remains functional. While potential risks exist, careful management and monitoring by a healthcare team can lead to significant benefits for the patient's recovery and long-term health. The selection of the appropriate feeding tube and administration method is critical for ensuring optimal nutritional support and quality of life.
For more detailed information, the American Society for Parenteral and Enteral Nutrition (ASPEN) offers extensive resources on enteral nutrition and patient care.
