Neurological and Muscular Disorders Affecting Swallowing
One of the most frequent reasons for requiring enteral nutrition is dysphagia, or difficulty swallowing. This can be caused by neurological conditions that impair the intricate muscular coordination needed for safe oral intake. When swallowing is compromised, there is a high risk of aspiration, where food or liquid enters the lungs, potentially causing pneumonia. Enteral feeding provides a safe alternative by delivering nutrients directly to the stomach or small intestine.
Examples of Neurological Conditions
- Stroke: A cerebrovascular accident can cause temporary or permanent dysphagia, depending on the severity and area of the brain affected.
- Parkinson's Disease: This progressive neurodegenerative disorder often leads to swallowing difficulties and digestive motility issues as the disease advances.
- Amyotrophic Lateral Sclerosis (ALS) / Motor Neurone Disease (MND): As these diseases progress, muscle weakness affects the ability to swallow, making enteral feeding essential for maintaining nutrition and hydration.
- Dementia (including Alzheimer's Disease): In later stages, cognitive decline can severely impact a person's ability to eat and drink sufficiently, requiring nutritional support.
- Traumatic Brain Injury: Severe head injuries and altered levels of consciousness often necessitate temporary or long-term tube feeding.
Severe Malnutrition and Inadequate Oral Intake
Beyond swallowing problems, significant malnutrition or the risk of it is a primary indicator for enteral support. This is often the case when patients cannot consume enough food orally to meet their energy demands due to prolonged anorexia, severe illness, or hypermetabolic states.
Conditions Related to Malnutrition
- Critical Illnesses: Patients in the intensive care unit (ICU) with conditions like severe burns, trauma, or respiratory failure (requiring a ventilator) have significantly increased metabolic needs. Enteral nutrition is often started early in these cases to prevent malnutrition and improve outcomes.
- Anorexia Nervosa: In severe cases where re-feeding must be done carefully under medical supervision, enteral feeding ensures controlled nutritional intake.
- Prolonged Anorexia: Long-term poor appetite resulting from various illnesses, or medical treatments, including chemotherapy, can lead to dangerous levels of weight loss and protein-energy undernutrition.
Gastrointestinal Disorders and Dysfunction
Enteral nutrition is necessary for a functional gastrointestinal tract, but some conditions can impede normal oral intake or nutrient absorption. In these cases, a feeding tube can be placed beyond the affected area to deliver nutrients effectively.
Digestive System Problems
- Inflammatory Bowel Disease (IBD): In severe cases, such as Crohn's disease, exclusive enteral nutrition can be used to induce remission, reduce inflammation, and supplement nutrients in patients with malabsorption.
- Short Bowel Syndrome: After surgical removal of a significant portion of the small intestine, some patients may require enteral feeding to supplement the limited nutrients they can absorb.
- Intestinal Motility Disorders: Conditions like gastroparesis or chronic intestinal pseudo-obstruction, where the gut muscles and nerves do not function correctly, can make oral feeding difficult and lead to nausea and vomiting.
- Bowel Obstruction: While a non-functional GI tract is a contraindication, in some cases a tube can be placed past a partial obstruction to allow for distal feeding.
Cancer and Its Treatment
Cancer patients often experience significant nutritional challenges due to the disease itself and the side effects of treatment. Tumor location, especially in the head, neck, or esophagus, can cause physical obstruction or painful swallowing (odynophagia), while chemotherapy and radiation therapy can cause nausea, vomiting, or taste changes.
Cancer-Related Needs
- Head and Neck Cancer: Tumors in these areas can physically block the passage of food, and treatments often cause severe mucositis (inflammation of the mucous membranes) and dry mouth, making eating painful or impossible.
- Esophageal and Stomach Cancer: Cancers in these areas can cause blockages or reduce the stomach's capacity, necessitating a feeding tube.
- Cancer Cachexia: This wasting syndrome involves significant weight loss, muscle atrophy, and anorexia. Enteral nutrition is used to manage and slow the progression of cachexia, which is a major factor in morbidity and mortality.
Comparison of Enteral and Parenteral Nutrition
When a patient needs nutritional support, a healthcare team determines the best course of action. The primary decision is between enteral nutrition (via the gut) and parenteral nutrition (via an intravenous line), and is based on the condition of the patient's gastrointestinal tract.
| Feature | Enteral Nutrition | Parenteral Nutrition |
|---|---|---|
| Route | Administered directly into the stomach or small intestine via a feeding tube. | Administered into the bloodstream via a central or peripheral IV line. |
| Gut Integrity | Helps preserve the structure and function of the gastrointestinal tract and gut flora, supporting immune function. | Bypasses the gastrointestinal tract, leading to gut atrophy over time. |
| Infection Risk | Associated with a lower risk of infection compared to parenteral nutrition. | Higher risk of systemic infections, especially with long-term central line access. |
| Cost | Generally less expensive than parenteral nutrition. | Significantly more costly due to specialized solutions and strict sterile procedures. |
| Complications | Potential complications include tube displacement, clogging, and aspiration. | Potential complications include refeeding syndrome, electrolyte imbalances, hyperglycemia, and liver dysfunction. |
| Primary Indication | Functional GI tract, but patient cannot eat or drink safely or sufficiently. | Non-functional GI tract, such as with a bowel obstruction or severe malabsorption. |
Conclusion
Enteral nutrition is a critical medical intervention for a wide array of conditions that prevent a person from consuming adequate nutrition orally, provided their gastrointestinal tract is functional. From neurological disorders causing dysphagia to cancer and severe malnutrition, this therapy is essential for preserving a patient's nutritional status, preventing complications, and supporting recovery. It remains the preferred method of nutritional support over intravenous feeding due to its numerous physiological benefits and lower risks. The specific condition, severity, and duration of need determine the type and method of enteral support required for each individual.
Visit the American Society for Parenteral and Enteral Nutrition for more resources and information on nutritional support.
