Key Takeaways
- X-ray is the gold standard for verifying initial NG tube placement; bedside pH testing (gastric pH <5) confirms ongoing placement
- Elevate head of bed 30-45 degrees during feeding and for 30-60 minutes afterward to prevent aspiration
- Check gastric residual volume (GRV) per facility policy before intermittent feedings; hold if residual exceeds threshold (typically >250-500 mL)
- Flush feeding tubes with 30 mL water every 4-6 hours for continuous feeds and before/after intermittent feeds and medications
- Common complications include aspiration, tube displacement, clogging, diarrhea, and electrolyte imbalances
Enteral Nutrition (Tube Feeding)
Enteral nutrition provides nutrition directly to the gastrointestinal tract when patients cannot meet their nutritional needs orally. It's preferred over parenteral (IV) nutrition because it maintains gut function and reduces complications.
Indications for Enteral Nutrition
Tube feeding is indicated when the GI tract is functional but oral intake is inadequate:
| Indication | Examples |
|---|---|
| Inability to swallow | Stroke, neurological disorders, sedation |
| Decreased level of consciousness | Traumatic brain injury, coma |
| Mechanical obstruction | Oral/esophageal cancer, facial trauma |
| Increased metabolic needs | Burns, sepsis, trauma |
| Failure to thrive | Inability to maintain weight orally |
| GI disorders | Short bowel syndrome (with functional gut) |
Types of Feeding Tubes
| Tube Type | Location | Duration | Key Features |
|---|---|---|---|
| Nasogastric (NG) | Nose to stomach | Short-term (<4-6 weeks) | Most common, easy to insert |
| Nasoduodenal/Jejunal | Nose to small intestine | Short-term | Reduces aspiration risk, for gastroparesis |
| Gastrostomy (PEG/G-tube) | Directly into stomach | Long-term | Surgical or endoscopic placement |
| Jejunostomy (J-tube) | Directly into jejunum | Long-term | For gastric dysfunction, lowest aspiration risk |
Tube Placement Verification
CRITICAL SAFETY POINT: Confirming correct tube placement before feeding is essential. Feeding into the lungs causes aspiration pneumonia, which can be fatal.
Methods of Verification
| Method | Use | Reliability |
|---|---|---|
| X-ray (radiograph) | Initial placement verification | Gold standard |
| pH testing | Ongoing verification | Gastric pH <5 (acidic), respiratory pH >6 |
| Auscultation | Historical method | NOT reliable—do NOT use alone |
| Aspirate appearance | Supportive information | Gastric = green/brown; intestinal = yellow/bile-stained |
pH Testing Guidelines
| Location | Expected pH |
|---|---|
| Gastric | <5 (often 1-4) |
| Intestinal | 6 or higher |
| Respiratory | >6 (if tube is in lungs) |
Note: Patients on acid-reducing medications (PPIs, H2 blockers) may have higher gastric pH, making pH testing less reliable.
When to Verify Placement
- Before each intermittent feeding
- At least every 4-8 hours for continuous feeding
- After vomiting, coughing, or suctioning
- If tube appears longer than previous marking
- If patient shows signs of respiratory distress
Administration Methods
Continuous Feeding
- Delivered via pump over 16-24 hours
- Best for critically ill patients
- Start slowly (10-40 mL/hr), advance as tolerated
- Reduces dumping syndrome and aspiration risk
Intermittent (Bolus) Feeding
- Delivered via gravity or syringe over 15-30 minutes
- Typically 250-400 mL every 4-6 hours
- More closely mimics normal eating patterns
- Higher aspiration risk than continuous
Aspiration Prevention
Aspiration is the most serious complication of tube feeding.
Prevention Strategies
- Elevate head of bed 30-45 degrees during feeding and for 30-60 minutes after
- Verify tube placement before each feeding
- Check gastric residual volume (GRV) per facility protocol
- Use continuous infusion for high-risk patients
- Consider post-pyloric (intestinal) feeding for patients with gastroparesis or high aspiration risk
- Stop feeding during procedures that require flat positioning
Signs of Aspiration
- Respiratory distress
- Coughing, choking during feeding
- Crackles or wheezes
- Fever, increased secretions
- Feeding formula in tracheal secretions
Gastric Residual Volume (GRV)
Gastric residual is the volume of contents remaining in the stomach. High residuals suggest delayed gastric emptying and increased aspiration risk.
GRV Guidelines
| Finding | Action |
|---|---|
| GRV <250-500 mL | Return residual, continue feeding |
| GRV >500 mL | Hold feeding, reassess, notify provider |
| Repeated high GRV | May need prokinetic agent or post-pyloric tube |
Note: Current evidence suggests GRV monitoring may be less predictive of aspiration than once thought. Follow facility policy—some institutions have moved away from routine GRV checks.
Tube Patency and Flushing
Tubes must be flushed regularly to prevent clogging:
| Situation | Flush Volume |
|---|---|
| Before and after intermittent feeding | 30 mL water |
| Before and after medications | 30 mL water |
| Every 4-6 hours for continuous feeding | 30 mL water |
| Clogged tube | Warm water, gentle pressure (never force) |
Medication Administration
- Use liquid forms when available
- Crush tablets finely and dissolve in water (check if safe to crush)
- Give each medication separately with flushes between
- Never mix medications with feeding formula
- Check for drug-nutrient interactions
Do NOT crush:
- Enteric-coated tablets
- Extended-release (XR, ER, SR) medications
- Sublingual medications
Complications of Enteral Nutrition
| Complication | Cause | Intervention |
|---|---|---|
| Aspiration | Improper positioning, high GRV, displaced tube | HOB elevation, check placement, hold feeding |
| Tube clogging | Inadequate flushing, crushed medications | Flush regularly, use liquid medications |
| Diarrhea | Rate too fast, formula intolerance, contamination | Slow rate, change formula, evaluate for C. diff |
| Constipation | Inadequate fluid, low fiber formula | Increase water flushes, consider fiber formula |
| Electrolyte imbalance | Refeeding syndrome, fluid shifts | Monitor labs, correct deficiencies |
| Tube displacement | Coughing, vomiting, patient pulling | Secure tube, verify placement |
| Skin breakdown | Leakage around stoma (G-tube/J-tube) | Skin barriers, stoma care, proper sizing |
Refeeding Syndrome
When malnourished patients begin receiving nutrition, refeeding syndrome can occur—a dangerous shift of electrolytes (especially phosphorus) into cells.
Signs of Refeeding Syndrome
- Hypophosphatemia
- Hypokalemia, hypomagnesemia
- Cardiac arrhythmias
- Respiratory failure
- Edema
Prevention
- Start feeding slowly in malnourished patients
- Monitor electrolytes daily initially
- Supplement phosphorus, potassium, magnesium as needed
On the Exam
NCLEX tests:
- Placement verification: X-ray is gold standard, pH testing for ongoing verification
- Aspiration prevention: HOB 30-45 degrees, verify placement, check GRV
- Medication administration: Flush before/after, use liquids, don't mix with formula
- Complications: Recognize signs and appropriate interventions
Key Takeaways
- X-ray verifies initial placement; pH <5 confirms gastric placement at bedside
- Elevate HOB 30-45 degrees during and 30-60 minutes after feeding
- Check GRV before intermittent feedings; hold if excessively high
- Flush with 30 mL water before/after feedings and medications
- Never crush enteric-coated or extended-release medications
What is the gold standard for verifying initial nasogastric tube placement before starting tube feeding?
A patient receiving continuous tube feeding should be positioned how during the infusion?
Before administering a medication through a feeding tube, the nurse should: