What is the management for a hemodialysis patient on prednisolone (corticosteroid) presenting with fever and a clot in the arteriovenous (AV) fistula?

Management of Thrombosed AV Fistula with Fever in an Immunocompromised Hemodialysis Patient

This patient requires immediate blood cultures, broad-spectrum antibiotics covering both gram-positive and gram-negative organisms (including Enterococcus), and urgent evaluation for both fistula thrombectomy and infection management, with the understanding that the fistula may need to be taken down if infection is confirmed. 1

Immediate Assessment and Stabilization

Rule Out Systemic Infection First

• Obtain blood cultures immediately before starting antibiotics – this patient has fever for 5 days in the setting of immunosuppression (prednisolone), making bacteremia highly likely. 1
• The combination of fever and thrombosed access raises serious concern for infected thrombus, which can lead to sepsis and death if not aggressively managed. 1
• Examine the fistula carefully for signs of local infection: erythema, warmth, tenderness, purulence, or skin changes. 2

Establish Alternative Dialysis Access

• Place a temporary non-tunneled dialysis catheter immediately (preferably right internal jugular vein) to enable urgent dialysis while managing the thrombosed fistula. 1, 3
• Avoid subclavian access as this can cause central venous stenosis. 3
• Do not attempt to use the thrombosed fistula for dialysis. 2

Antibiotic Management

Empiric Therapy

• Start broad-spectrum IV antibiotics immediately after blood cultures covering:
  • Gram-positive organisms (Staphylococcus, Streptococcus)
  • Gram-negative bacilli
  • Enterococcus 1
• Vancomycin plus an aminoglycoside is the recommended initial regimen. 2
• This patient's immunosuppression with prednisolone increases infection risk and severity, making aggressive empiric coverage essential. 1

Duration and Adjustment

• If AV fistula infection is confirmed, treat for 6 weeks similar to subacute bacterial endocarditis. 1, 2
• Adjust antibiotics based on culture results and sensitivities. 1
• If the patient remains symptomatic beyond 36 hours despite antibiotics, this suggests the access is the source and may require surgical intervention. 1

Management of the Thrombosed Fistula

Decision Algorithm for Thrombectomy vs. Surgical Takedown

If infection is present:

• Fistula takedown is required in cases of septic emboli or uncontrolled infection at the AV anastomosis. 4
• Systemic sepsis from access infection requires surgical exploration and removal of infected segments. 4
• Do not attempt thrombectomy if there are signs of infection – this can lead to septic embolization and death. 1

If no infection is identified:

• Percutaneous thrombectomy can be attempted with mechanical devices, achieving technical success in approximately 89% of native fistulas. 5
• For large clot burden, consider catheter-directed thrombolytic infusion with recombinant tissue plasminogen activator (rTPA) followed by angioplasty of any underlying stenosis. 6
• Critical caveat: The underlying cause of thrombosis (typically venous stenosis) must be identified and corrected, or rapid re-thrombosis will occur in >90% of cases. 1

Imaging and Intervention

• Fluoroscopy fistulography is the preferred initial imaging study to evaluate for underlying stenosis. 2
• Duplex ultrasound is an acceptable alternative. 2
• Any stenosis >50% with associated clinical abnormalities should be treated with percutaneous transluminal angioplasty. 2

Special Considerations in This Case

Immunosuppression Impact

• Prednisolone therapy significantly increases infection risk and may mask typical inflammatory signs. 1
• The 5-day fever history suggests established infection rather than simple mechanical thrombosis. 7
• Consider molecular diagnostic methods (e.g., multipathogen PCR) if blood cultures remain negative but clinical suspicion for sepsis is high, as this can provide results in 15 hours with 96% specificity. 7

Hypercoagulability Assessment

• In immunocompromised patients with recurrent thrombosis, consider underlying hypercoagulable states. 8
• If thrombectomy is performed and rapid re-thrombosis occurs despite correction of stenosis, systemic anticoagulation may be needed. 8

Clinical Pitfalls to Avoid

• Never attempt to use a thrombosed, potentially infected fistula for dialysis – this can cause septic embolization. 1
• Do not delay temporary catheter placement – the patient needs dialysis and the thrombosed fistula cannot be relied upon. 1
• Do not perform thrombectomy before ruling out infection – mechanical disruption of infected thrombus is dangerous. 1
• Do not use subclavian vein for temporary access – this permanently compromises future ipsilateral arm access options. 3

Follow-up After Acute Management

• If fistula is salvaged after thrombectomy, it will require close monitoring as primary patency at 3 months is only 63-75%. 5
• Most salvaged fistulas require secondary interventions (average 2.2 procedures) to maintain function. 9
• If the fistula must be taken down due to infection, plan for alternative permanent access in a different location or contralateral limb after infection resolution. 4