What are the immediate steps to take in the event of a dialysis shunt malfunction?

Immediate Management of Dialysis Shunt Malfunction

In the event of a dialysis shunt malfunction, immediate assessment and intervention are required to restore access function, with urgent referral for fluoroscopic fistulography or ultrasound duplex Doppler evaluation followed by appropriate intervention based on the specific cause of malfunction. 1

Initial Assessment

Signs of Shunt Malfunction

• Absent pulse and thrill on physical examination (indicates thrombosis)
• Abnormal clinical indicators:
  • Reduction in dialysis blood flow rates
  • Poor dialysis adequacy (reduced Kt/V)
  • Difficulty with cannulation
  • Prolonged bleeding after needle removal
  • Swelling in the extremity with the access
  • Development of collateral veins

Immediate Bedside Evaluation

1. Assess for pulse and thrill at the access site
2. Check for signs of infection (redness, warmth, tenderness)
3. Evaluate for abnormal skin changes (thinning, ulceration, eschar)
4. Look for evidence of pseudoaneurysm formation
5. Check for signs of steal syndrome (pain, coldness, numbness in the extremity)

Emergency Management Algorithm

For Suspected Thrombosis (No Pulse/Thrill)

1. Immediate referral for intervention (within hours) to prevent permanent access loss 1

2. Imaging options:

   • Fluoroscopic fistulography (first choice for suspected thrombosis) 1
   • Ultrasound duplex Doppler (alternative if fistulography not immediately available)

3. Intervention options:

   • Endovascular thrombectomy with balloon angioplasty
   • Surgical thrombectomy and revision
   • Catheter-directed thrombolysis with alteplase (for recent thrombosis) 2

For Dysfunctional But Patent Access (Weak Pulse/Thrill)

1. Urgent referral (within 24-48 hours) for evaluation

2. Imaging options:

   • Ultrasound duplex Doppler or fluoroscopic fistulography (equivalent alternatives) 1

3. Intervention based on findings:

   • Stenosis: Balloon angioplasty (success rates 92-98%) 1
   • Central venous stenosis: Endovascular stenting
   • Pseudoaneurysm without infection: Consider stent graft placement 1

For Complications Requiring Immediate Attention

1. Active bleeding/rupture:

   • Apply direct pressure (avoid tourniquet if possible)
   • Urgent surgical consultation 1

2. Signs of infection:

   • Blood cultures before antibiotics
   • Broad-spectrum antibiotics
   • Surgical consultation for possible access removal 1

3. Severe steal syndrome:

   • Urgent surgical consultation for potential banding or revision 1

Temporary Access Management

If the existing access cannot be salvaged immediately:

1. Placement of temporary dialysis catheter for emergency dialysis 1

   • Nontunneled catheter for very short-term use (<2 weeks)
   • Tunneled catheter if longer access needed

2. Catheter placement considerations:

   • Internal jugular vein preferred over subclavian (to prevent central stenosis)
   • Ultrasound guidance recommended
   • Avoid femoral site if possible (higher infection risk)

Prevention of Recurrence

After successful intervention:

1. Regular surveillance with:

   • Monthly clinical monitoring
   • Access flow measurements
   • Ultrasound evaluation for high-risk accesses 1

2. Early intervention for:

   • Flow rates <450-500 mL/min in AVF 1
   • Venous pressure to mean arterial pressure ratio >0.55 in AVG 1

Common Pitfalls to Avoid

1. Delayed intervention: Thrombosed accesses require immediate attention; success rates decline significantly after 48 hours 3

2. Overlooking central stenosis: Swelling of the extremity with collateral veins suggests central venous stenosis requiring specific intervention 1

3. Missing steal syndrome: Ischemic symptoms (pain, coldness, numbness) require urgent attention to prevent tissue loss 1

4. Inadequate infection management: Infected accesses often require complete removal rather than salvage attempts 4

5. Excessive catheter use: Prolonged catheter dependence increases infection risk and mortality; prioritize definitive access restoration 1