What is the recommended duration of antibiotic therapy for catheter-related bloodstream infections (CRBSI)?

Duration of Antibiotic Therapy for Catheter-Related Bloodstream Infections (CRBSI)

The recommended duration of antibiotic therapy for catheter-related bloodstream infections varies based on the pathogen, catheter management, and presence of complications, with uncomplicated infections requiring 5-7 days if the catheter is removed and 10-14 days if retained. 1

General Duration Guidelines

• For uncomplicated CRBSI where the catheter is removed, treat with antibiotics for 5-7 days 2, 1
• For uncomplicated CRBSI where the catheter is retained, treat with antibiotics for 10-14 days in combination with antibiotic lock therapy 2, 1
• Duration should be extended to 4-6 weeks for complicated infections (endocarditis, suppurative thrombophlebitis, osteomyelitis) 2, 1

Pathogen-Specific Recommendations

Coagulase-Negative Staphylococci

• 5-7 days of antibiotic therapy if the catheter is removed 2
• 10-14 days of antibiotic therapy plus antibiotic lock therapy if the catheter is retained 2
• Some patients may be observed without antibiotics if the catheter is removed, they have no intravascular or orthopedic hardware, and follow-up blood cultures confirm absence of bacteremia 2
• Recent evidence suggests that even shorter courses (≤3 days) may be safe after catheter removal 3

Staphylococcus aureus

• 4-6 weeks of antimicrobial therapy with mandatory catheter removal 2, 1
• Shorter duration (≥14 days) may be considered if:
  • Patient is not diabetic or immunosuppressed
  • Infected catheter is removed
  • No prosthetic intravascular devices present
  • No evidence of endocarditis or suppurative thrombophlebitis
  • Fever and bacteremia resolve within 72 hours of appropriate therapy
  • No evidence of metastatic infection 2
• Transesophageal echocardiography (TEE) should be performed for patients being considered for shorter therapy 2
• TEE should be done 5-7 days after onset of bacteremia to minimize false-negative results 2
• Early studies showed that therapy <10 days was associated with relapsing infection 4

Enterococci

• 7-14 days for uncomplicated enterococcal CRBSI when the catheter is removed or when a long-term catheter is retained and antibiotic lock therapy is used 2
• TEE should be performed if there are signs of endocarditis, prolonged bacteremia/fever despite appropriate therapy, radiographic evidence of septic pulmonary emboli, or presence of prosthetic valves 2

Gram-Negative Bacilli

• 10-14 days is the standard recommendation 1
• Recent evidence suggests that ≤7 days of appropriate antibiotic therapy may be as effective as longer courses once the catheter has been removed 5, 6

Candida species

• 14 days after the first negative blood culture with mandatory catheter removal 2, 1
• All patients with candidemia should be treated 2

Factors Affecting Treatment Duration

• Catheter management: Shorter duration if catheter is removed; longer if retained 1
• Clinical response: Extend therapy if fever or bacteremia persist beyond 72 hours 2, 1
• Complications: Presence of endocarditis, suppurative thrombophlebitis, or metastatic infection requires extended therapy (4-6 weeks) 2, 1

When to Remove the Catheter

• Mandatory removal for:
  • S. aureus infections 2
  • Candida species infections 2
  • Mycobacterial infections 2
  • Tunnel or exit-site infections 2
  • Persistent bacteremia (>72 hours) despite appropriate therapy 1

Common Pitfalls

• Failing to extend therapy for complicated infections or persistent bacteremia 1
• Inadequate duration when the catheter is retained 1
• Not removing the catheter when indicated (e.g., S. aureus, persistent bacteremia) 1
• Not obtaining follow-up blood cultures to confirm clearance of bacteremia 2

Recent Evidence

• A 2024 multicenter trial showed that 7 days of antibiotic treatment was noninferior to 14 days for bloodstream infections (excluding S. aureus and certain other complicated cases) 7
• This supports the trend toward shorter antibiotic courses for uncomplicated infections when appropriate source control is achieved 7

Monitoring Response

• Assess for clinical improvement within 48-72 hours of initiating appropriate antimicrobial therapy 1
• Persistent bacteremia beyond 72 hours suggests inadequate source control, inappropriate antimicrobial selection, or complications 1
• Consider surveillance blood cultures 1 week after completion of therapy if the catheter has been retained 2