What are the guidelines for the placement and management of a Nasogastric (NG) tube?

Guidelines for Nasogastric (NG) Tube Placement and Management

Fine bore (5-8 French gauge) nasogastric tubes should be used for enteral tube feeding unless there is a need for repeated gastric aspiration or administration of high viscosity feeds/drugs via the tube. 1

Tube Selection and Placement

Types of Tubes

• Nasogastric (NG) tubes:

  • Use fine bore 5-8 French gauge tubes for most feeding situations
  • Large bore PVC tubes should be avoided as they irritate the nose/esophagus and increase risks of gastric reflux and aspiration 1
  • No evidence supports using weighted NG tubes for better placement or position maintenance 1

• Nasojejunal (NJ) tubes:

  • Indicated for patients with gastric reflux, delayed gastric emptying
  • Essential for unconscious patients who must be nursed flat
  • All are fine bore (6-10 French gauge) 1

Placement Verification

• NG tube position must be checked using pH testing prior to every use 1
• NJ tube position should be confirmed by x-ray 8-12 hours after placement 1
• Auscultation alone is not reliable for confirming tube position 1, 2
• X-ray remains the gold standard for checking correct tube placement but causes significant delays in feeding 1, 3

Special Considerations

• Avoid NG tube insertion for three days after acute variceal bleeding 1
• Accidental bronchial insertion is common in patients with reduced consciousness or impaired gag/swallowing reflexes 1
• Endotracheal tubes in ventilated patients do not necessarily prevent bronchial insertion 1

Tube Management

Maintenance

• Long-term NG and NJ tubes should be changed every 4-6 weeks, swapping to the other nostril 1
• Consider gastrostomy or jejunostomy when feeding is likely needed for >4-6 weeks 1
• Some evidence suggests considering gastrostomy at 14 days for certain patients (e.g., post-stroke dysphagia) 1
• Loosening and rotating gastrostomy tubes may prevent blockage through mucosal overgrowth and reduce peristomal infections 1

Feed Administration

• Gastric feeding (vs. small intestine) permits use of hypertonic feeds, higher rates, and bolus feeding 1
• Position patients at 30° or more during feeding and for 30 minutes after to minimize aspiration 1
• Continuous feed should not be given overnight in patients at risk of aspiration 1
• In patients with doubtful GI motility, check gastric aspirates every four hours; if >200ml, review feeding policy 1

Complication Prevention and Management

Common Complications

1. Insertion-related:

   • Perforation of pharyngeal/esophageal pouches
   • Intracranial insertion (rare)
   • Bronchial insertion (common in at-risk patients)
   • Approximately 25% of NG tubes "fall out" or are pulled out soon after insertion 1

2. Post-insertion:

   • Nasopharyngeal discomfort, sore mouth, thirst, swallowing difficulties
   • Local pressure effects: nasal erosions, abscess formation, sinusitis, otitis media
   • Esophageal damage: esophagitis, ulceration, stricturing (with long-term use)

3. Feeding-related:

   • Refeeding syndrome (monitor electrolytes closely)
   • Aspiration
   • Diarrhea (often related to medications, particularly antibiotics) 1

Prevention Strategies

• Monitor fluid, glucose, sodium, potassium, magnesium, calcium, and phosphate status in the first few days 1
• Administer drugs via ETF tube in liquid form, separately from feed with tube flushing before and after 1
• Avoid bacterial contamination of feeds which can cause sepsis, pneumonia, UTIs 1
• Allow breaks in feeding to let gastric pH fall to prevent bacterial overgrowth 1
• Consider fiber-containing feeds and 4-8 hour feeding breaks for ETF-related diarrhea 1

Discharge Planning

• Ensure adequate liaison with community carers before discharge
• Provide training in pump use, infection control, feeding stoma care
• Give patients/carers a list of expert contacts
• Ensure continuing prescription of feed and equipment is in place 1

Special Considerations

• Suitability for gastrostomy placement should be assessed by an experienced gastroenterologist or nutrition support team member 1
• Expert advice on the prognosis of swallowing difficulties may be needed 1
• Ethical considerations must always be addressed before initiating enteral feeding 1

The evidence clearly demonstrates that proper tube placement verification, appropriate tube selection, and vigilant monitoring for complications are essential for reducing morbidity and mortality associated with NG tube placement and management.