What is the management approach for catheter-related infections?

Management of Catheter-Related Infections

Immediate Decision: Remove or Retain the Catheter

The catheter must be removed immediately if there is purulence at the exit site, erythema overlying the catheter, clinical signs of sepsis, positive blood cultures with certain organisms (S. aureus, Candida, Pseudomonas species, Bacillus, Corynebacterium, or mycobacteria), tunnel infection, port abscess, septic thrombosis, or endocarditis. 1, 2

When Catheter Removal is MANDATORY:

• S. aureus bacteremia: Remove catheter immediately due to high risk of endocarditis and metastatic infection 1, 3
• Candida or fungal infections: All tunneled CVCs and implantable devices must be removed with documented fungemia 1
• Gram-negative infections with specific organisms: Pseudomonas (non-aeruginosa), Burkholderia cepacia, Stenotrophomonas, Agrobacterium, Acinetobacter baumannii require removal, especially if bacteremia persists or patient becomes unstable 1
• Bacillus or Corynebacterium species: Vast majority require catheter removal 1
• Mycobacterial infections (M. fortuitum, M. chelonae): Catheter removal mandatory 1
• Tunnel infection or port abscess: Remove catheter, perform incision and drainage if indicated 1, 2
• Septic thrombosis: Remove catheter in all cases 2

When Catheter May Be Retained:

• Coagulase-negative staphylococci in hemodynamically stable patients without evidence of persistent bacteremia, metastatic complications, or prosthetic devices 1
• Tunneled CVCs with uncomplicated intraluminal infection: Can attempt salvage with systemic antibiotics plus antibiotic lock therapy for 14 days 1

Diagnostic Workup Before Treatment

Obtain two sets of blood cultures (one drawn percutaneously, one from the catheter) before initiating antibiotics. 1, 2

• Use quantitative blood cultures or differential time to positivity (≥2 hours earlier growth from catheter vs peripheral) to confirm catheter-related infection 1
• Culture catheter tip using semiquantitative or quantitative methods if removed (≥15 cfu for semiquantitative, ≥10³ cfu for quantitative) 1
• Culture any purulent drainage from exit site 1

Organism-Specific Antibiotic Therapy

Staphylococcus aureus:

Use nafcillin or oxacillin for methicillin-susceptible strains—vancomycin is inferior and should NOT be used for MSSA. 1, 2

• Perform transesophageal echocardiography (TEE) in all patients without contraindications to rule out endocarditis due to high complication rates 1, 2
• If TEE negative and catheter removed: treat for 14 days 1
• If endocarditis present: treat for 4-6 weeks 1
• Vancomycin reserved only for MRSA or severe β-lactam allergy 2
• Screen nares for S. aureus colonization and treat carriers with mupirocin 2% ointment in patients requiring continued IV access 1

Coagulase-Negative Staphylococci:

• Catheter removal with 5-7 days systemic antibiotics for uncomplicated infection 1
• If catheter retained: longer duration therapy required (14 days with antibiotic lock therapy for tunneled catheters) 1

Gram-Negative Bacilli:

• Nontunneled CVCs: Remove catheter and treat for 10-14 days 1
• Tunneled CVCs that cannot be removed: Systemic plus antibiotic lock therapy for 14 days; quinolones (ciprofloxacin ± rifampin) preferred as they can be given orally 1
• Empiric therapy for suspected gram-negative CRBSI: Must include anti-pseudomonal coverage, especially in neutropenic patients 1
• Prolonged bacteremia after catheter removal: Extend therapy to 4-6 weeks, especially with underlying valvular disease 1

Candida Species:

All patients with candidemia require treatment; remove all tunneled CVCs and implantable devices immediately. 1

• Hemodynamically unstable patients or prior fluconazole exposure: Use amphotericin B 1
• Hemodynamically stable patients without recent fluconazole: Can use fluconazole 400-600 mg daily for susceptible organisms 1
• Candida krusei: Must use amphotericin B 1
• Duration: 14 days after last positive blood culture and resolution of symptoms 1
• Catheter salvage NOT recommended: Success rates only ~30% with antibiotic lock therapy 1

Malassezia furfur:

• Discontinue intralipids, remove catheter, treat with amphotericin B 1

Catheter Reinsertion Timing

For nontunneled catheters: May reinsert after appropriate systemic antimicrobial therapy is begun 1, 2

For tunneled CVCs and implantable devices: Postpone reinsertion until after appropriate systemic therapy is begun based on susceptibilities AND repeat blood cultures are negative 1, 2

• Ideally in stable patients: Complete full antibiotic course, then wait 5-10 days and confirm negative repeat blood cultures before reinsertion 1

Special Considerations for Tunneled Catheters

Exit Site Infections (Uncomplicated):

• No systemic signs, no purulence: Topical therapy only (mupirocin for S. aureus, ketoconazole for Candida) 1
• Fails topical therapy or purulent drainage present: Add systemic antibiotics; remove catheter if systemic therapy fails 1

Antibiotic Lock Therapy:

• Use for salvage attempts in tunneled CVCs with uncomplicated intraluminal infections (coagulase-negative staphylococci, S. aureus, gram-negative bacilli) for 14 days combined with systemic therapy 1
• Recommended for hemodialysis catheters when catheter is retained 1

Critical Pitfalls to Avoid

Never use vancomycin for methicillin-susceptible S. aureus—it has higher failure rates and promotes vancomycin resistance. 1, 2

• Do not routinely remove catheters in patients with fever and mild-to-moderate illness without other indications—71% of suspected infected catheters are sterile 1
• Do not use qualitative broth cultures of catheters—only quantitative or semiquantitative methods are recommended 1
• Do not attempt catheter salvage for fungal infections—removal is mandatory 1
• Do not delay TEE in S. aureus bacteremia—endocarditis rates are high and change treatment duration 1, 2
• If bacteremia or fungemia persists ≥3 days after catheter removal and appropriate antibiotics, aggressively evaluate for septic thrombosis, endocarditis, and metastatic infections 1, 2