Antibiotic Lock Therapy for Hemodialysis Catheters
Prophylactic antimicrobial lock solution should be used in hemodialysis patients with long-term catheters who have a history of multiple catheter-related bloodstream infections (CRBSI) despite optimal adherence to aseptic technique. 1
Indications for Antibiotic Lock Therapy
- Antibiotic lock therapy is indicated for patients with CRBSI involving long-term catheters with no signs of exit site or tunnel infection for whom catheter salvage is the goal 1
- Antibiotic lock should be used in patients with a history of multiple CRBSI despite optimal adherence to aseptic technique 1
- For patients with multiple positive catheter-drawn blood cultures that grow coagulase-negative staphylococci or gram-negative bacilli and concurrent negative peripheral blood cultures, antibiotic lock therapy can be given without systemic therapy for 10-14 days 1
Recommended Antibiotic Lock Protocol
- Antibiotic lock should not be used alone for active CRBSI; it should be used in conjunction with systemic antimicrobial therapy, with both regimens administered for 10-14 days 1
- For hemodialysis patients, the antibiotic lock solution should be renewed after every dialysis session 1
- The antibiotic is combined with heparin and instilled into each catheter lumen at the end of each dialysis session 1
- For vancomycin locks, the concentration should be at least 1000 times higher than the MIC (e.g., 5 mg/mL) of the microorganism involved 1
- Gentamicin-based lock solutions (4 mg/mL with heparin) have shown significant reduction in CRBSI rates compared to heparin alone 2, 3
Effectiveness Based on Pathogen
- Success rates for antibiotic lock therapy vary by pathogen:
- Catheter removal is recommended for CRBSI due to S. aureus and Candida species, instead of treatment with antibiotic lock and catheter retention, unless there are unusual extenuating circumstances (e.g., no alternative catheter insertion site) 1
Novel Lock Solutions
- A novel lock solution containing 0.24 M (7.0%) sodium citrate, 0.15% methylene blue, 0.15% methylparaben, and 0.015% propylparaben has shown significant reduction in CRBSI compared to heparin (0.24 vs. 0.82 per 1000 catheter days) 4
- Daptomycin lock therapy has shown promising results for CRBSI from coagulase-negative staphylococci and methicillin-sensitive S. aureus, but not for methicillin-resistant S. aureus 5
Important Considerations and Caveats
- Antibiotic concentrations must be 100 to 1000 times greater to kill sessile bacteria within a biofilm than to kill planktonic bacteria 1
- The ability of an antibiotic to eradicate a biofilm is not predicted by its inherent spectrum of antibacterial activity, as biofilms display different resistance mechanisms 6
- Recurrent bacteremia after parenteral therapy is more likely to occur if therapy is administered through a retained catheter than if the catheter is removed 1
- At this time, there are insufficient data to recommend an ethanol lock for the treatment of CRBSI 1
- Surveillance blood cultures should be obtained 1 week after completion of an antibiotic course for CRBSI if the catheter has been retained 1