A nasogastric (NG) tube provides a vital route for delivering nutrition when a person cannot eat or drink adequately by mouth. The types of substances administered through an NG tube are carefully selected by a healthcare professional, such as a dietitian, based on the patient's specific health requirements. These feeds fall into several categories, each designed to meet different physiological needs. Adherence to a prescribed feeding plan and proper administration techniques are crucial for patient safety and successful nutritional support.
Commercial Liquid Formulas
Commercial formulas are the most common type of feed administered through an NG tube. They are nutritionally complete, sterile, and designed to flow easily through the tube without causing blockages. There are several sub-types of commercial formulas.
Polymeric Formulas
Polymeric formulas are the standard, most frequently used type of enteral feed. They contain intact, whole proteins, carbohydrates, and fats, similar to the nutrients found in a healthy diet. These formulas are suitable for most patients with a normally functioning digestive system.
Hydrolyzed Formulas
Also known as elemental or semi-elemental formulas, these feeds contain proteins that have been pre-digested or broken down into smaller peptides and amino acids. They are prescribed for patients with compromised digestive systems or malabsorption issues who cannot properly digest whole proteins. This can include individuals with conditions such as Crohn's disease or pancreatitis.
Disease-Specific Formulas
For patients with specific medical conditions, specialized formulas are available. Examples include those tailored for diabetes (with a specific macronutrient profile), renal disease (designed to limit electrolyte load), or conditions requiring immune support. These are always used under strict medical supervision.
Water and Medications
In addition to nutritional feeds, water and certain medications can be administered via an NG tube.
Water Flushes
Water is essential for hydration and is regularly flushed through the tube to prevent it from becoming clogged. A water flush is typically given before and after each feed and medication dose. Cooled boiled water is often recommended for flushes.
Medications
Medications must be in liquid, soluble, or finely crushed form to prevent clogging. Not all tablets can be crushed; slow-release, extended-release, or enteric-coated medications are strictly prohibited. Each medication must be administered separately, with a water flush in between, to prevent interactions. A pharmacist should always be consulted before giving any new medication through the tube.
Blenderized Tube Feeding (BTF)
Blenderized diets, made from pureed whole foods, have gained interest as an alternative to commercial formulas. However, significant precautions and professional guidance are required.
BTF through a Nasogastric Tube
It is crucial to note that many healthcare providers and institutions do not recommend using blenderized diets with thin, fine-bore nasogastric tubes. The primary risk is tube blockage, which is more likely with smaller diameter tubes. While suitable for larger gastrostomy tubes, administering BTF through an NG tube should be undertaken only with extreme caution and with specific instructions from a registered dietitian and healthcare team.
Best Practices for Safe Administration
To ensure safe and effective feeding, several best practices must be followed:
- Verify tube placement: The position of the NG tube must be checked before every use by aspirating stomach contents and checking the pH level. The pH should be 5.5 or lower, unless the patient is on acid-suppressing medication.
- Maintain proper positioning: The patient should be propped up at a 30 to 45-degree angle during feeding and for at least an hour afterward to prevent reflux and aspiration.
- Wash hands: Hand hygiene is critical before handling any feeding equipment.
- Check for clogs: If the tube becomes blocked, use a gentle push-pull action with warm water to attempt to clear it. Never use excessive force or attempt to clear with foreign objects.
- Monitor for intolerance: Watch for signs of discomfort such as bloating, nausea, vomiting, or diarrhea and report them to a healthcare provider.
Comparison of Standard Polymeric vs. Hydrolyzed Formulas
| Feature | Standard Polymeric Formula | Hydrolyzed Formula |
|---|---|---|
| Protein State | Intact, whole proteins | Broken-down peptides and amino acids |
| Digestion | Requires normal digestive function | Easier to digest and absorb |
| Cost | Generally more cost-effective | Typically more expensive |
| Ideal For | Patients with normal digestive capacity | Patients with malabsorption or impaired digestive function |
| Fiber Content | Available with or without fiber | Often fiber-free, but variations exist |
| Common Use | Wide range of conditions, most common | Conditions like pancreatitis or Crohn's disease |
Conclusion
Multiple types of feeds can be safely administered through a nasogastric tube, including standard, hydrolyzed, and disease-specific commercial formulas, along with water and specific medications. However, homemade blenderized diets are generally not recommended for thin NG tubes due to a high risk of clogging. The choice of feed is highly individualized and must be determined by a healthcare team to ensure the patient's specific nutritional and medical needs are met safely. Adhering to proper protocols for checking tube placement, administration, and hygiene is paramount for preventing complications like aspiration or blockage. For further information on enteral formula selection, consult the BAPEN website.
Remember, the correct use of a nasogastric tube and its feeds is a team effort involving the patient, caregivers, and medical professionals to provide effective and safe nutritional support.
