What is the treatment for an infected Arteriovenous Fistula (AVF) in a dialysis patient?

Treatment of Infected Arteriovenous Fistula in Dialysis Patients

Infected AVFs require immediate initiation of broad-spectrum antibiotics (vancomycin plus an aminoglycoside) for 6 weeks, cessation of cannulation at the infected site with arm rest, and urgent surgical evaluation if the AV anastomosis is involved, as infection at this site requires immediate resection of infected tissue. 1

Immediate Management Steps

Antibiotic Therapy

• Start empiric broad-spectrum antibiotics immediately with vancomycin plus an aminoglycoside to cover both Gram-positive (including Staphylococcus aureus and coagulase-negative staphylococci) and Gram-negative organisms 1
• Coverage must include Enterococcus given increasing trends of enterococcal infections in dialysis access 1
• Continue antibiotics for a full 6 weeks, analogous to treatment for subacute bacterial endocarditis 1, 2
• Adjust antibiotic therapy based on culture and sensitivity results once available 1

Local Access Management

• Immediately cease cannulation at the infected site 1, 2
• Rest the affected arm completely until infection resolves 1, 2
• Obtain blood cultures and wound cultures to guide definitive antibiotic therapy 1

Surgical Intervention Requirements

Infections at Cannulation Sites

• Most AVF infections occur at cannulation sites and can be managed conservatively with antibiotics and access rest 1
• Cannulation must stop at the infected site, but the fistula itself typically does not require surgical intervention 1, 2

Infections at the AV Anastomosis

• Infections at the AV anastomosis require immediate surgical referral and resection of infected tissue 1, 3
• If arterial segments require resection, reconstruction options include venous interposition grafting or creation of a more proximal AV anastomosis using only degradable suture material 1
• This is a surgical emergency due to risk of catastrophic complications including septic emboli, bacteremia, and death 1, 3, 4

Indications for Complete Fistula Takedown

• Septic emboli mandate complete fistula takedown 1
• Uncontrolled systemic sepsis despite appropriate antibiotics requires surgical exploration and possible complete AVF removal 3
• Metastatic infectious complications (such as bacterial meningitis or endocarditis) necessitate complete access removal 3, 4

Monitoring for Complications

Life-Threatening Sequelae

• Access-related bacteremia can lead to metastatic complications including endocarditis, septic arthritis, osteomyelitis, and bacterial meningitis 1, 4
• The immunocompromised status of dialysis patients makes any access infection potentially lethal 1
• Mortality from catheter-related infections in dialysis patients can reach 14-25%, emphasizing the severity of vascular access infections 5

Clinical Surveillance

• Monitor for systemic signs of infection including fever, chills, and hemodynamic instability 2
• Evaluate for local signs of worsening infection including expanding erythema, purulent drainage, or tissue necrosis 2
• Repeat blood cultures during and after antibiotic therapy to confirm clearance 1

Alternative Dialysis Access During Treatment

• Establish temporary dialysis access via catheter if the infected AVF cannot be used 3
• Plan for alternative permanent access in a different location or contralateral limb if fistula takedown is required 3
• Avoid using the infected fistula until complete resolution of infection and completion of the 6-week antibiotic course 1, 2

Critical Pitfalls to Avoid

• Never attempt to continue using an infected AVF for dialysis—this risks systemic sepsis and metastatic complications 1, 2
• Do not delay surgical consultation when the AV anastomosis is involved—these infections require immediate surgical intervention within hours, not days 3, 6
• Do not shorten the 6-week antibiotic course—premature discontinuation leads to recurrence and catastrophic complications 1, 6
• Do not rely on antibiotics alone for anastomotic infections—surgical resection is mandatory in addition to prolonged antibiotics 1, 3, 6

Distinguishing AVF Infection from Inflammation

• Infection presents with erythema, warmth, tenderness, purulent drainage, and systemic symptoms (fever, chills) 2
• Non-infectious inflammation after dialysis may present with swelling and tenderness but lacks purulence and systemic symptoms 2
• If infection cannot be ruled out clinically, treat as infection with full antibiotic course rather than risk undertreating 1, 2