What is the recommended G (gastrostomy) tube flush rate?

Recommended G-Tube Flush Rate

Gastrostomy tubes should be flushed with at least 30 mL of water before and after feeding, and every 4 hours during continuous feeding to prevent tube obstruction. 1

Evidence-Based Flushing Protocol

Water Volume Requirements

• Minimum volume: 30 mL of water per flush 1
• Frequency:
  • Before and after each bolus feeding 1
  • Every 4 hours during continuous feeding 1
  • Before and after medication administration 1

Type of Water

• Sterile water is generally recommended, though practices vary between institutions 1
• Recent evidence suggests tap water is a safe and cost-effective alternative in most settings 2
• Reserve sterile water for cases with compromised immune systems or concerns about tap water safety

Flushing Technique

• Use a 50 mL syringe for administration 1
• Apply gentle, consistent pressure to avoid tube damage
• Ensure complete flush through the entire tube length

Preventing Tube Occlusion

Tube occlusion occurs in 20-45% of cases and can increase up to 10-fold when checking gastric residuals 1. Proper flushing is essential to maintain tube patency.

Common Causes of Occlusion

• Interaction between protein-based formulas and acidic environment 1
• Medication administration without proper flushing 1
• Smaller diameter tubes (especially jejunostomy tubes) clog more easily 1

Effective Flushing Agents

• Water is the most effective flushing agent 1, 3
• Cranberry juice and carbonated beverages have been shown to be inferior to water 1, 3
• Some evidence supports prophylactic use of pancreatic enzymes to prevent occlusion 1

Managing Tube Occlusion

If occlusion occurs despite preventive measures:

1. First attempt: Simple water flush (resolves approximately one-third of obstructions) 1
2. Second attempt: Installation of pancreatic enzymes (can reopen an additional 50% of occluded tubes) 1
3. Last resort: Mechanical devices (Fogarty balloon, biopsy brush, or commercial tube decloggers) 1
4. If all else fails: Tube replacement 1

Special Considerations

Tube Material Impact

• Polyurethane tubes have lower clogging rates than silicone tubes 3
• Tube diameter (8Fr, 10Fr, 12Fr) has not shown significant effect on clogging rates 3

pH Considerations

• Formula clotting is more likely in acidic environments (pH 5.0 or less) 4
• Flushing before and after checking gastric residuals is particularly important to prevent acid precipitation of formula in the tube 4

Early Feeding After Placement

• G-tubes can be safely flushed with 60 mL of sterile water as early as 4 hours after placement 5
• This early flushing protocol has been shown to be safe and cost-effective 5

Pitfalls to Avoid

• Inadequate flushing volume: Using less than 30 mL may not adequately clear the tube
• Improper medication administration: Always flush before and after medication administration
• Using acidic solutions: Avoid flushing with acidic solutions that can precipitate formula proteins
• Neglecting regular maintenance: Tubes should be cleaned daily with water and soap 1
• Excessive force during flushing: Can damage the tube or cause discomfort

Implementing these evidence-based flushing protocols will help maintain tube patency, reduce complications, and ensure effective delivery of nutrition and medications.