NG Tube Insertion and Enteral Nutrition

Nasogastric (NG) tube insertion is a common nursing procedure in UAE hospitals, performed for decompression of the stomach (in bowel obstruction, post-operative ileus, or upper GI bleeding) and for enteral feeding in patients who cannot meet their nutritional requirements orally. The DOH (UAE) examination tests your competence in NG tube insertion technique, confirming proper placement, managing enteral feeds, and preventing complications such as aspiration pneumonia and tube misplacement. In a region with a high prevalence of diabetes, stroke, and head/neck cancers (all conditions that may impair oral intake), enteral nutrition support is a critical nursing competency.

---

🟢 Lite — Quick Review (1h–1d)

Rapid summary for last-minute revision before your exam.

NG Tube Placement Verification — ALWAYS Required Before Any Use:

Method	What It Tells You
X-ray (gold standard)	Confirms tip is below diaphragm, above pylorus
Aspirate pH	pH ≤ 5.5 = gastric placement; pH ≥ 6 = intestinal/ respiratory placement
Capillary reflux	Aspirate returns easily with gentle syringe pull
Patient assessment	Can the patient speak? (if oral/nasal — they’d struggle to speak)

NEVER rely on: Bubbles in water, auscultation (whoosh sound), or colour of aspirate alone.

Key Formula — NG Feeding Rate: Volume (mL) ÷ Time (hours) × Drop factor (20 or 60) ÷ 60 = drops/min Example: 240 mL over 8 hours via gravity set (20 drops/mL): (240 ÷ 8) × 20 ÷ 60 = 10 drops/min

⚡ Exam Tip: If a patient with an NG tube develops respiratory distress, coughing, or cyanosis during tube insertion — STOP immediately, remove the tube, and reassess. The tube may have entered the airway rather than the oesophagus.

---

🟡 Standard — Regular Study (2d–2mo)

Standard content for students with a few days to months.

1. Types of NG Tubes

Tube Type	Use	Features
Levine tube	Gastric decompression; single-lumen	Most common; single use
** Salem sump**	Gastric decompression; double-lumen with vent	Preferred for decompression (sump action); blue vent port
Dobhoff tube	Enteral feeding; small-bore	Weighted tip; radiopaque line; meant for feeding only
Feeding tube with stylet	Difficult insertion	Stiffening wire inside for easier passage; MUST remove stylet before use

Sizes:

• Large-bore tubes (14–18 Fr): For decompression; easier to insert; more uncomfortable
• Small-bore tubes (8–12 Fr): For feeding; harder to place; more comfortable long-term

2. NG Tube Insertion Procedure

Equipment:

• NG tube (appropriate size; Dobhoff or levine)
• Water-soluble lubricant
• 50 mL catheter-tip syringe
• pH paper (range 1–11)
• Glass of water with straw (if patient can swallow safely)
• tissues
• drainage bag or cap
• Tape to secure
• Suction equipment (if for decompression)
• Safety pin and elastic band for securing tube to gown

Procedure:

1. Explain procedure and obtain consent
2. Assess nostril patency (ask patient to sniff; check each side)
3. Measure tube length: Nose → Ear → Xiphoid process (NEX method) or NEX + 10 cm for post-pyloric placement
4. Perform hand hygiene; don gloves
5. Lubricate tube tip
6. Insert tube along the floor of the nostril (not upward along the septum — follow the natural curve)
7. Advance gently; when tip reaches posterior pharynx (15 cm), ask patient to swallow (if safe to do so) and advance during swallowing
8. Continue advancing until measured mark is reached
9. Aspirate — obtain gastric contents; check pH
10. X-ray confirmation is the gold standard before first use (and after any episode of dislodgement)
11. Secure tube to nose with tape (ventilator-dependent patients or long-term — use bridle if at risk of dislodgement)
12. Position patient: Sit upright (Fowler’s 30–45°) or left lateral decubitus to promote gastric emptying
13. Cap the tube or connect to suction/drainage bag as ordered
14. Document: Date/time, tube type and size, nostril used, length at nose, aspirate pH, patient tolerance

3. Verifying NG Tube Placement

X-ray is the GOLD STANDARD and the only definitive method:

• A chest X-ray showing the tube below the diaphragm and above the pylorus confirms gastric placement
• The tube must be visible as a radiopaque line on X-ray
• All UAE facilities require X-ray confirmation before initiating feeds

Aspiration pH Method (supplemental to X-ray):

• Aspirate 0.5–1 mL of fluid from the tube
• Test with pH paper
• pH ≤ 5.5 = gastric placement (acceptable to start feeding)
• pH ≥ 6 = may be intestinal or respiratory placement (do NOT feed; recheck X-ray)
• pH 7+ = probable respiratory placement (MUST remove tube)

Aspirate Appearance:

• Gastric: Green/yellow, off-white, brownish (bile, stomach acid)
• Intestinal: Clear to yellow (more alkaline)
• Respiratory: Thin, frothy, pale (pleural fluid)

Signs of Respiratory Placement (MUST remove immediately):

• Patient is coughing, choking, dyspnoeic
• Unable to speak (hoarseness is an early sign)
• Tube cannot be aspirated
• Patient vomits
• Cyanosis

4. NG Tube Feeding Management

A. Types of Enteral Feeds

Feed Type	Indication
Isotonic polymeric (e.g., Ensure, Ensure Plus)	Standard feeding; normal GI function
High-protein	Wound healing, trauma, burns
High-energy (1.5–2 kcal/mL)	Fluid restriction, high requirements (e.g., critically ill)
Disease-specific	Diabetes (lower glycaemic index), renal failure, hepatic failure
Elemental/semi-elemental	Malabsorption, short bowel syndrome, pancreatic insufficiency

B. Feeding Methods

Bolus feeding:

• 200–300 mL delivered via syringe over 15–20 minutes, every 3–4 hours
• Advantages: Simple; mimics normal meal pattern
• Disadvantages: Risk of reflux, diarrhoea, nausea

Continuous infusion:

• Pump-controlled feeding over 16–24 hours
• Advantages: Better tolerated; less reflux; more physiological for gut
• Used for: Critically ill, poorly tolerating bolus, post-pyloric feeds

C. Administering NG Medications

• Use liquid formulations whenever possible
• Crush only if tablet is safe to crush (NOT enteric-coated, NOT modified-release)
• Dissolve in 15–30 mL warm water
• Flush tube with 15–30 mL water before and after medication
• Do NOT mix medications directly with enteral feed (can cause incompatibilities)
• Never add medication to the feeding bag

---

🔴 Extended — Deep Study (3mo+)

Comprehensive coverage for students on a longer study timeline.

5. Complications of NG Tubes and Enteral Feeding

A. Aspiration Pneumonia (Most Serious)

• Occurs when gastric contents are regurgitated and aspirated into the lungs
• Risk factors: Supine position, delayed gastric emptying, large bore tubes, high-volume bolus feeds
• Prevention: Elevate head of bed 30–45°; use prokinetic agents (metoclopramide, erythromycin) if delayed gastric emptying; check residuals before each bolus feed
• If suspected: Stop feeds immediately; notify physician; ABC assessment; O₂ support; suction if needed; chest X-ray

B. Tube Misplacement

• NG tubes can enter the trachea, bronchi, or pleural space (especially in confused or uncooperative patients, or those with swallowing difficulties)
• This is a CRITICAL SAFETY ISSUE — death can result from pneumothorax
• ALWAYS verify placement before use and after any episode of dislodgement or vomiting
• If respiratory symptoms occur during insertion → REMOVE TUBE IMMEDIATELY

C. Gastrointestinal Complications

• Nausea, vomiting, bloating: Common; often due to high residual volumes, rapid infusion rate, cold feed, or lactose intolerance
• Diarrhoea: Most common GI complication; causes include antibiotics (C. difficile), formula choice, contamination, rapid infusion, hypoalbuminaemia
• Constipation: Fluid inadequate, fibre inadequate, immobility
• Clogged tube: Common with small-bore tubes; prevention: flush with 30 mL water before and after feeds and medications; use crushed medications dissolved well

D. Metabolic Complications

• Refeeding syndrome (in severely malnourished patients): Hypophosphataemia, hypokalaemia, hypomagnesaemia, fluid overload; occurs when feeding is started too aggressively
• Hyperglycaemia: Common in critically ill, diabetic patients; monitor blood glucose; may need insulin
• Dehydration/hypernatremia: Inadequate free water flushes

6. Gastric Residual Volume (GRV) — Current Evidence

What it is: The volume of fluid remaining in the stomach after a period without feeding.

Traditional practice: Hold feeds if GRV > 200–500 mL (varies by facility).

Current evidence (and UAE practice is evolving):

• GRV alone is NOT a reliable predictor of aspiration risk
• Routine GRV measurement is being questioned by evidence
• Some UAE facilities have updated protocols: Check GRV only if patient shows signs of intolerance (vomiting, distension, discomfort)
• Clinical assessment remains critical

If your facility still uses GRV monitoring:

• Use a 50–60 mL syringe; aspirate gently
• If GRV is high (per your protocol): Notify physician; consider prokinetic; hold or slow feeds

7. Specific Patient Populations

A. Stroke Patients (High Incidence in UAE)

• Dysphagia (swallowing difficulty) is common post-stroke
• NG tube feeding is often required for the first 2–4 weeks post-stroke
• Consider early speech and language therapy assessment for swallowing
• Most stroke patients who recover swallowing function will transition to oral intake
• Long-term dysphagia → consider PEG tube (percutaneous endoscopic gastrostomy)

B. Head and Neck Cancer Patients

• Often have NG tubes or PEG tubes due to tumour location, surgery, or chemoradiation
• Require meticulous oral care (mucositis is common)
• May have high nutritional requirements due to catabolic state

C. Critically Ill Patients

• Early enteral nutrition (within 24–48 hours of ICU admission) is recommended if oral intake is not possible
• Target: 25–30 kcal/kg/day; 1.2–2 g protein/kg/day
• Hypocaloric feeding in early phase (first week) may be appropriate
• Gastric feeding is first-line; post-pyloric if gastric residual volumes are persistently high

Exam Watch: The DOH exam frequently tests the scenario of an NG tube that has been inadvertently removed or dislodged. The nurse must NOT reconnect the tube to feeds or suction until placement is re-verified by X-ray. Another common question involves a patient who develops aspiration pneumonia — the priority nursing action is to place the patient in a lateral position, suction the airway, administer oxygen, and notify the physician immediately.

---

Content adapted based on your selected roadmap duration. Switch tiers using the selector above.