How should I manage a central line-associated bloodstream infection in an adult, including catheter removal, empiric broad‑spectrum antibiotics (covering MRSA, Pseudomonas, and Candida), dosing adjustments for renal impairment or vancomycin allergy, antibiotic lock therapy if the catheter cannot be removed, and appropriate treatment duration?

Management of Central Line-Associated Bloodstream Infection (CLABSI)

Remove the catheter immediately and initiate empiric broad-spectrum antibiotics covering MRSA, Pseudomonas, and Candida for any patient with suspected CLABSI who has severe sepsis, purulent drainage at the exit site, tunnel infection, or infection caused by S. aureus, Pseudomonas species, or Candida species. 1

Immediate Diagnostic Steps

Before initiating treatment, obtain paired blood cultures—one from the catheter and one from a peripheral vein—to confirm the diagnosis and identify the causative organism. 1 If purulent drainage is present at the exit site, submit it for Gram stain and culture (including fungal and acid-fast organisms if the patient is immunocompromised). 2

Catheter Removal: Mandatory Indications

The catheter must be removed in the following situations:

• Severe sepsis or hemodynamic instability 1
• Tunnel infection or port abscess (catheter salvage is impossible in these cases) 3
• Purulent drainage at the exit site 1
• Infections caused by S. aureus, Pseudomonas species, or Candida species (for both short-term and long-term catheters) 1
• Persistent bacteremia or fungemia >72 hours after appropriate antibiotic therapy 1
• Suppurative thrombophlebitis or endocarditis 1
• Metastatic infection (osteomyelitis, septic emboli) 1

For hemodialysis catheters specifically, S. aureus, Pseudomonas, and Candida infections always require immediate catheter removal and insertion at a new anatomical site. 1

Empiric Antibiotic Therapy

Start empiric therapy immediately after obtaining blood cultures:

• Vancomycin (15-20 mg/kg IV every 8-12 hours, adjusted for renal function) to cover MRSA and coagulase-negative staphylococci 1
• Plus an antipseudomonal agent based on local antibiogram:
  • Third-generation cephalosporin (ceftazidime), OR
  • Carbapenem (meropenem), OR
  • β-lactam/β-lactamase combination (piperacillin-tazobactam) 1

Add empiric antifungal coverage (echinocandin or fluconazole) if the patient has:

• Total parenteral nutrition 1
• Prolonged broad-spectrum antibiotic use 1
• Hematologic malignancy or transplant 1
• Femoral catheterization 1
• Candida colonization at multiple sites 1

For femoral catheters in critically ill patients, always include empiric Candida coverage. 1

Vancomycin Allergy or Renal Impairment Adjustments

If the patient has a vancomycin allergy, substitute with daptomycin (6 mg/kg IV daily, adjusted for renal function) or linezolid (600 mg IV/PO every 12 hours). 1 For hemodialysis patients with vancomycin-resistant enterococci, use daptomycin 6 mg/kg after each dialysis session or linezolid 600 mg every 12 hours. 1

De-escalation Based on Culture Results

Once susceptibilities are available:

• Methicillin-susceptible S. aureus (MSSA): Switch from vancomycin to cefazolin (2 g IV every 8 hours, or 20 mg/kg after dialysis for hemodialysis patients) 1
• Coagulase-negative staphylococci: Continue vancomycin or switch to cefazolin if susceptible 1
• Gram-negative organisms: Narrow to the most appropriate agent based on susceptibilities 1
• Candida species: Use an echinocandin (caspofungin, micafungin, or anidulafungin) or fluconazole if no azole exposure in the past 3 months and low risk of C. krusei or C. glabrata 1

Catheter Salvage: When and How

Catheter salvage may be attempted ONLY in uncomplicated CLABSI involving long-term catheters (tunneled or implanted devices) when:

• The infection is caused by coagulase-negative staphylococci or gram-negative bacilli (NOT S. aureus, Pseudomonas, or Candida) 1
• There is no tunnel infection, port abscess, or purulent drainage 1
• The patient shows clinical improvement within 48-72 hours of antibiotic initiation 1
• No metastatic complications are present 1

For catheter salvage, use antibiotic lock therapy (ALT) in combination with systemic antibiotics:

• Instill high-concentration antibiotics (e.g., vancomycin 5 mg/mL or gentamicin 5 mg/mL) into the catheter lumen 1
• Dwell time should not exceed 48 hours; preferably reinstall every 24 hours 1
• Continue ALT for 10-14 days along with systemic antibiotics 1
• Obtain repeat blood cultures at 72 hours; if positive, remove the catheter 1

Research supports that ALT combined with systemic antibiotics reduces catheter replacement rates from 33% to 10% compared to systemic antibiotics alone. 4 However, ALT has a 20% relapse rate and is ineffective for fungal infections (70% failure rate). 1, 4

Antibiotic Duration

Treatment duration depends on organism, catheter removal, and complications:

• Uncomplicated CLABSI with catheter removal: 10-14 days of systemic antibiotics 1
• Uncomplicated CLABSI with catheter retention (using ALT): 10-14 days of systemic antibiotics plus ALT 1
• Tunnel infection without bacteremia: 7-10 days after catheter removal 3
• S. aureus bacteremia:
  • If transesophageal echocardiography (TEE) is negative and catheter removed: 14 days 1
  • If TEE is positive or persistent bacteremia >72 hours: 4-6 weeks 1
• Candida bloodstream infection: 14 days after the last positive blood culture and catheter removal 1
• Complicated infections (endocarditis, suppurative thrombophlebitis): 4-6 weeks 1
• Osteomyelitis: 6-8 weeks 1

For hemodialysis patients, if symptoms resolve within 2-3 days and no metastatic infection is present, the catheter can be exchanged over a guidewire and ALT used for 10-14 days. 1

Catheter Reinsertion Timing

Do not reinsert a tunneled catheter until:

• The patient has completed the full antibiotic course 1
• Repeat blood cultures obtained 5-10 days after completion are negative 1
• For hemodialysis catheters, a long-term catheter can be placed once blood cultures are negative (does not require waiting until after antibiotic completion) 1

If immediate vascular access is needed, insert a temporary non-tunneled catheter at a different anatomical site—never at the same site as the infected catheter. 3

Special Considerations for Hemodialysis Catheters

Hemodialysis patients have unique management considerations due to limited vascular access sites. 1 For infections caused by organisms other than S. aureus, Pseudomonas, or Candida, empiric antibiotics can be started without immediate catheter removal. 1 If symptoms resolve within 2-3 days and no metastatic infection is present, the catheter can be exchanged over a guidewire or retained with ALT. 1 However, if symptoms persist beyond 2-3 days or metastatic infection develops, the catheter must be removed. 1

Monitoring and Follow-Up

Obtain repeat blood cultures 48-72 hours after catheter removal and antibiotic initiation to confirm clearance of bacteremia. 3 If fever persists beyond 72 hours despite appropriate therapy and catheter removal, evaluate for septic thrombosis or endocarditis with TEE. 3 For hemodialysis patients with retained catheters, obtain surveillance blood cultures 1 week after completing antibiotics; if positive, remove the catheter. 1

Common Pitfalls to Avoid

Do not use vancomycin for MSSA infections—switch to cefazolin once susceptibilities confirm methicillin susceptibility, as vancomycin is inferior for MSSA bacteremia. 1 Never attempt catheter salvage for S. aureus, Pseudomonas, or Candida infections—these organisms have high failure rates and increased mortality when catheters are retained. 1, 5 Do not use ALT alone without systemic antibiotics—it is ineffective as monotherapy. 1 Avoid guidewire exchange in the presence of tunnel infection or purulent drainage—this spreads infection and worsens outcomes. 1