What to do if a nephrostomy (percutaneous catheter used to divert urine directly from the kidneys) has no output?

Management of a Nephrostomy with No Output

When a nephrostomy has no output, immediate evaluation and intervention are required to determine the cause and restore drainage, as this can lead to serious complications including infection, renal damage, and deterioration of kidney function.

Initial Assessment

Check for mechanical causes first:

• Catheter position and patency:
  • Inspect the external portion of the catheter for kinks or compression 1
  • Check if the catheter is properly secured to prevent displacement 2
  • Ensure collection system is positioned below the level of the kidney

Immediate interventions:

1. Flush the catheter gently:

   • Use sterile technique with a small volume (5-10 mL) of sterile saline
   • Never forcefully flush as this may cause injury or introduce infection
   • Observe for resistance which suggests obstruction

2. Assess for catheter occlusion:

   • Blood clots
   • Debris or sediment
   • Mucus plugs
   • Mineral deposits

3. Check patient hydration status:

   • Dehydration can reduce urine output
   • Ensure adequate fluid intake or IV hydration if needed

Diagnostic Evaluation

If initial measures don't restore output:

1. Imaging studies:

   • Obtain a nephrostogram (contrast study through the nephrostomy tube) to:
     • Confirm catheter position
     • Identify obstruction or kinks
     • Assess for contrast extravasation
   • Consider CT if nephrostogram is inconclusive

2. Laboratory assessment:

   • Check renal function (BUN, creatinine)
   • Urinalysis and culture if infection suspected
   • Complete blood count to assess for infection

Management Algorithm

If catheter is obstructed:

1. Attempt catheter clearance:

   • Gentle irrigation with sterile saline
   • Consider urokinase or tissue plasminogen activator for blood clots
   • If unsuccessful, proceed to catheter exchange

2. Catheter exchange:

   • Replace with a new nephrostomy tube of appropriate size
   • Consider using a larger diameter tube if recurrent obstruction occurs
   • Always maintain access with a safety wire during exchange 2

If catheter is malpositioned:

1. Reposition existing catheter if possible under fluoroscopic guidance
2. Replace catheter if repositioning fails
3. Consider upsizing the catheter to prevent recurrence 1

If no mechanical issue is identified:

1. Evaluate for physiological causes:

   • Acute kidney injury
   • Severe dehydration
   • Decreased renal perfusion

2. Consider additional drainage options:

   • Placement of a second nephrostomy tube
   • Antegrade ureteral stent placement 1
   • Combined "rendez-vous" technique if complex obstruction 1

Special Considerations

For infected systems:

• Avoid complicated, prolonged procedures in an infected, obstructed system 2
• Ensure adequate antibiotic coverage before manipulation 2
• Prioritize drainage over complex interventions initially

For long-term management:

• Consider converting to a larger, self-retaining catheter for prolonged drainage 3
• Reinforce thin catheters with protective outer tubing to prevent kinking 4
• Regular scheduled exchanges (typically every 2-3 months) to prevent complications

Common Pitfalls to Avoid

1. Never lose access to an obstructed kidney once punctured - always use a safety wire 2
2. Don't forcefully flush an obstructed catheter - may cause pyelovenous backflow and sepsis
3. Don't ignore persistent bleeding after manipulation - may indicate vascular injury requiring angiographic evaluation 2
4. Don't delay intervention for a non-functioning nephrostomy in a patient with signs of infection or deteriorating renal function

When to Seek Additional Help

• Persistent lack of output despite interventions
• Signs of sepsis or worsening infection
• Significant bleeding after manipulation
• Deteriorating renal function

Remember that nephrostomy tubes are subject to fracture, dislodgement, and occlusion 1, so prompt evaluation and management of a non-functioning tube is essential to preserve kidney function and prevent complications.