What is the recommended treatment for catheter-related bloodstream infections?

Treatment of Catheter-Related Bloodstream Infections

For catheter-related bloodstream infections (CRBSI), initiate empirical therapy with vancomycin for gram-positive coverage (particularly MRSA) plus an antipseudomonal agent for gram-negative coverage, with catheter removal strongly recommended for most cases to reduce mortality and prevent complications. 1

Empirical Antibiotic Therapy

Gram-Positive Coverage

• Vancomycin is the cornerstone of empirical therapy in healthcare settings with elevated MRSA prevalence 1
• For institutions where MRSA isolates have vancomycin MIC values >2 μg/mL, use alternative agents such as daptomycin instead 1
• Linezolid should NOT be used for empirical therapy in patients suspected but not proven to have bacteremia 1
• In units with low MRSA prevalence, cefazolin may substitute for vancomycin 1

Gram-Negative Coverage

• Base empirical gram-negative coverage on local antimicrobial susceptibility data and disease severity 1
• Options include fourth-generation cephalosporins, carbapenems, or β-lactam/β-lactamase combinations, with or without aminoglycosides 1
• For neutropenic patients, severely septic patients, or those colonized with multidrug-resistant organisms, use empirical combination therapy for Pseudomonas aeruginosa until culture results allow de-escalation 1

Special Situations Requiring Broader Coverage

• Femoral catheters in critically ill patients: Add coverage for gram-negative bacilli AND Candida species in addition to gram-positive coverage 1
• Suspected catheter-related candidemia: Use empirical antifungal therapy for septic patients with risk factors including total parenteral nutrition, prolonged broad-spectrum antibiotics, hematologic malignancy, transplant recipients, femoral catheterization, or multi-site Candida colonization 1
• For empirical candidemia treatment, use an echinocandin (preferred) or fluconazole in selected stable patients 1

Catheter Management

When to Remove the Catheter

Catheter removal is critical and should occur in the following situations:

• Severe sepsis or hemodynamic instability 1
• Persistent bacteremia despite appropriate antibiotics 1
• Complicated infections including septic thrombosis, endocarditis, or metastatic infection 1
• Tunnel or exit-site infection with purulence 1
• Infections caused by S. aureus, Candida species, Pseudomonas (non-aeruginosa), Bacillus, Corynebacterium, or mycobacteria 1
• Nontunneled catheters with documented CRBSI 1

When Catheter Retention May Be Considered

• Uncomplicated coagulase-negative staphylococcal infections in tunneled catheters without persistent bacteremia 1
• Selected cases of tunneled catheter infections where systemic plus antibiotic lock therapy is used 1

Important caveat: Exchanging catheters over a guidewire is NOT recommended when infection is present 2

Pathogen-Specific Treatment Duration

Staphylococcus aureus

• Perform transesophageal echocardiography (TEE) in patients without contraindications to identify complicating endocarditis 1
• Uncomplicated bacteremia with catheter removal and negative TEE: 14 days of therapy 1
• Complicated infection or positive TEE: 4-6 weeks of therapy 1
• Day 1 of therapy is defined as the first day with negative blood cultures 1

Gram-Negative Bacilli

• Nontunneled catheters with catheter removal: 10-14 days of appropriate antimicrobial therapy 1
• For Pseudomonas species (other than P. aeruginosa), Burkholderia cepacia, Stenotrophomonas, Agrobacterium, or Acinetobacter baumannii, strongly consider catheter removal, especially if bacteremia persists or patient becomes unstable 1
• Prolonged bacteremia after catheter removal with underlying valvular disease: 4-6 weeks of therapy 1

Candida Species

• All tunneled catheters or implantable devices must be removed for documented fungemia 1
• Amphotericin B for hemodynamically unstable patients or those with prolonged fluconazole exposure 1
• Fluconazole for stable patients without recent fluconazole therapy and susceptible organisms 1
• Echinocandins (caspofungin, micafungin, or anidulafungin) are preferred for empirical therapy 1
• Duration: 14 days after last positive blood culture and resolution of symptoms 1
• C. krusei infections require amphotericin B 1

Antibiotic Lock Therapy

For tunneled catheters that cannot be removed, antibiotic lock therapy combined with systemic antibiotics may be attempted 1

Recommended Lock Concentrations

• Vancomycin: 2.5-5.0 mg/mL (5.0 mg/mL more efficacious for biofilm eradication) 1
• Cefazolin: 5.0 mg/mL for methicillin-susceptible staphylococci 1
• Gentamicin: 1.0 mg/mL for gram-negative organisms 1
• Ceftazidime: 0.5 mg/mL for gram-negative organisms 1
• Ciprofloxacin: 0.2 mg/mL for gram-negative organisms 1
• 70% ethanol lock for mixed infections 1

Research evidence supports antibiotic lock efficacy: Studies demonstrate significantly reduced catheter removal rates when vancomycin lock therapy is combined with systemic antibiotics compared to systemic therapy alone 3, 4

Hemodialysis Patients

Empirical Regimen

• Vancomycin 20 mg/kg loading dose during last hour of dialysis, then 500 mg during last 30 minutes of each subsequent session 1
• PLUS gentamicin 1 mg/kg (max 100 mg) after each dialysis session 1
• OR ceftazidime 1 g IV after each session 1

Common Pitfalls to Avoid

• Failing to remove the catheter when indicated is the most critical error, as it significantly increases mortality and complication rates 1
• Not performing TEE in S. aureus bacteremia misses complicating endocarditis requiring prolonged therapy 1
• Using linezolid empirically before bacteremia is confirmed 1
• Inadequate empirical coverage for Pseudomonas in neutropenic or severely ill patients 1
• Attempting salvage therapy for Candida-infected tunneled catheters (success rates only ~30%) 1
• Treating for insufficient duration after catheter removal, particularly with S. aureus 1
• Not considering local antibiogram data when selecting empirical gram-negative coverage 1