Management of Obstructed Nasogastric (NG) Line
To manage an obstructed NG tube, first attempt flushing with warm water, and if unsuccessful, use a solution of pancreatic enzymes which has a 96% success rate in clearing formula-related blockages. 1, 2
Causes of NG Tube Obstruction
NG tubes frequently become blocked due to several factors:
- Inadequate flushing before and after medication administration or feeds
- Medication-related issues:
- Crushed tablets
- Hyperosmolar drugs
- Potassium supplements
- Iron supplements
- Sucralfate
- Thick or viscous medications
- Formula clotting
- Gastric mucosal overgrowth (specifically in gastrostomy tubes)
- Physical obstructions (knotting, seeds, etc.)
Step-by-Step Management Algorithm
1. Prevention Strategies
- Flush tube with 30-60 mL of fresh tap, cooled boiled, or sterile water before and after every feed or medication 1
- Use liquid medications whenever possible instead of crushed tablets
- Administer medications separately from feeds
- For gastrostomy tubes: loosen and rotate the tube weekly to prevent mucosal overgrowth 1
2. Initial Management of Blockage
- Attempt to flush with 30-60 mL of warm water using gentle pressure 1
- Never use excessive force as this may rupture the tube
- Position patient upright if possible to use gravity assistance
3. If Initial Flushing Fails
- Try a solution of activated pancreatic enzymes:
- Insert a small catheter into the feeding tube to apply the enzyme solution directly to the obstruction site
- This method has shown 96% success in clearing formula-related clots when water has failed 2
4. Alternative Methods (Less Evidence-Based)
- Some experts suggest using an alkaline solution of pancreatic enzymes 1
- A guidewire or commercially available tube declogger may be used by an expert for PEG tubes 1
- Caution: While some practitioners suggest carbonated beverages like cola, this is not recommended due to the sugar content increasing risk of bacterial contamination 1
5. If Blockage Persists
- For NG tubes: consider tube replacement if the above measures fail
- For gastrostomy/jejunostomy tubes: consider tube replacement or surgical intervention if blockage cannot be cleared 1
- Assess for tube position before attempting any feeding after clearing a blockage
Special Considerations
Types of Blockages That May Require Immediate Replacement
- Tablet impaction
- Knotted feeding tube
- Foreign material occluding the feeding port
- Complete formula clotting throughout the tube length 2
Monitoring After Clearing
- Confirm tube patency by aspirating gastric contents
- Check pH of aspirate to confirm proper positioning before resuming feeds
- Monitor for signs of tube displacement or aspiration
Pitfalls and Caveats
- Never use excessive force when attempting to clear an obstruction as this may cause tube rupture or displacement
- Avoid using acidic solutions like fruit juices as they may cause tube degradation 1
- Do not use sodium bicarbonate solution as it may degrade certain types of tubes 1
- For long-term feeding needs (>4-6 weeks), consider switching from nasal tubes to percutaneous tubes (PEG) which have lower rates of blockage and dislodgement 1
- Fine bore tubes (5-8 French gauge) are more prone to blockage than larger bore tubes but are more comfortable for patients 1
By following this systematic approach, most obstructed NG tubes can be successfully cleared, minimizing the need for tube replacement and associated patient discomfort.