What if nothing comes out of the Nasogastric (NG) tube when turned on to suction?

Troubleshooting a Non-Functioning Nasogastric (NG) Tube

If nothing comes out of the NG tube when turned on to suction, first check for tube patency by flushing with 30ml of water, as the tube may be blocked by gastric mucosa, medication residue, or kinked tubing. 1

Initial Assessment of NG Tube Function

When an NG tube is not producing any output on suction, follow this systematic approach:

1. Check tube position:

   • Confirm proper placement with pH testing prior to any intervention 2
   • Verify that the tube hasn't migrated or become dislodged
   • Consider obtaining an x-ray if position is uncertain

2. Check for tube patency:

   • Attempt to flush with 30ml of warm water 2
   • If resistance is met, the tube may be blocked

3. Common causes of blockage:

   • Tube occlusion by gastric mucosa (especially with gastrostomy tubes) 2
   • Medication residue (particularly crushed tablets, hyperosmolar drugs, potassium supplements) 2
   • Thick or viscous feeds that haven't been adequately flushed 2
   • Kinking or compression of the tube

Interventions for Non-Functioning NG Tubes

For blocked tubes:

• Flush with warm water (first-line approach) 2
• If unsuccessful, try an alkaline solution of pancreatic enzymes 2
• Avoid using carbonated drinks, pineapple juice, or sodium bicarbonate as they may degrade the tube 2

For tubes with positional issues:

• Reposition the patient (turn to left side to optimize gastric positioning)
• Advance or withdraw the tube slightly (1-2cm) if appropriate
• Ensure proper fixation to prevent displacement (40-80% of NG tubes become dislodged when not properly secured) 1

For gastric emptying issues:

• Consider that lack of output may indicate delayed gastric emptying or ileus
• Ondansetron should not be used as it may mask progressive ileus and gastric distention 3
• Consider prokinetic agents like metoclopramide (10-20mg every 6 hours) 1

Special Considerations

• Important: Remember that NG tubes are not drugs that stimulate gastric or intestinal peristalsis and should not be used instead of nasogastric suction when indicated 3

• Caution: Lack of output could indicate tube misplacement. Misplacement and subsequent use of an NG tube is considered a "never event" 4

• Risk factors for complications:

  • Recent abdominal surgery (possible ileus)
  • Altered mental status (increased risk of tube displacement) 2
  • Mechanical obstruction
  • Gastroparesis

When to Consider Alternative Approaches

If NG tube function cannot be restored:

• Consider tube replacement if blockage persists
• For long-term feeding needs (>4-6 weeks), consider PEG placement 2, 1
• For patients with high aspiration risk or gastroparesis, consider post-pyloric feeding 1

Documentation and Monitoring

• Document all troubleshooting attempts
• Monitor for signs of intolerance (abdominal distension, discomfort)
• Position patient at 30° or higher during and after feeding to reduce aspiration risk 1
• Monitor gastric residual volumes before each feeding (consider delaying next feed if residual volume exceeds 150ml) 1

Remember that proper tube maintenance (regular flushing before and after medications or feeds) is essential to prevent future blockages 2.