Vancomycin Initiation for CRBSI in Hemodialysis Patients
For hemodialysis patients with CRBSI, initiate vancomycin with a loading dose of 20-25 mg/kg (actual body weight) administered during the last 60-90 minutes of the hemodialysis session, followed by maintenance doses of 1000-1500 mg (approximately 15-20 mg/kg) given during the last hour of each subsequent dialysis session. 1, 2, 3
Loading Dose Strategy
- Administer a weight-based loading dose of 20-25 mg/kg based on actual body weight to rapidly achieve therapeutic concentrations, regardless of dialysis timing 2, 3
- This typically translates to 1500-2000 mg for most patients 3
- The loading dose should be given during the last 60-90 minutes of the dialysis session to prevent vascular damage and preserve vascular access 3
Maintenance Dosing Regimen
- Give maintenance doses of 1000-1500 mg (approximately 15-20 mg/kg) during the last hour of each dialysis session using high-flux membranes 3, 4
- Fixed maintenance doses of 1000 mg are often insufficient, with 41.67% of patients receiving <15 mg/kg achieving subtherapeutic levels 4
- Target pre-dialysis trough concentrations of 15-20 μg/mL 2, 3
- Administering vancomycin during (rather than after) dialysis reduces exposure by approximately 25%, necessitating dose adjustment to approximately 1400 mg for a typical patient 5
Empirical Coverage Requirements
- Vancomycin must be combined with gram-negative coverage (third-generation cephalosporin, carbapenem, or β-lactam/β-lactamase combination) based on local antibiogram for empirical CRBSI therapy 1
- This dual coverage is mandatory until culture results guide de-escalation 1
Catheter Management Considerations
- Remove the infected catheter immediately for CRBSI due to S. aureus, Pseudomonas species, or Candida species and insert a temporary catheter at a different anatomical site 1
- For other pathogens (coagulase-negative staphylococci, non-Pseudomonas gram-negative bacilli), initiate antibiotics 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 adjunctive antibiotic lock therapy for 10-14 days 1
Monitoring and Adjustment
- Measure pre-dialysis vancomycin concentrations before the second dialysis session to ensure levels are 15-20 μg/mL 2, 3
- High-flux polyethersulfone membranes remove approximately 39% of vancomycin, with significant variability (±13%) 6
- Polyethersulfone high-flux membranes (PES-AP) result in lower concentrations (5.95 mg/mL) compared to medium-low flux membranes (PES-BP, 7.27 mg/mL), with 31.58% vs 0% subtherapeutic rates respectively 4
- Body weight, dialysis duration, blood flow rate, and dialysate flow rate are not reliable predictors of vancomycin removal 6
De-escalation Strategy
- Switch from vancomycin to cefazolin 20 mg/kg (actual body weight, rounded to nearest 500 mg) after each dialysis session when cultures confirm methicillin-susceptible S. aureus 1, 7
- This switch is mandatory to reduce toxicity risk and improve outcomes 1
Duration of Therapy
- Administer 10-14 days of therapy for uncomplicated CRBSI with catheter removal or exchange and symptom resolution within 2-3 days 1, 7
- Extend to 4-6 weeks for persistent bacteremia >72 hours, endocarditis, or suppurative thrombophlebitis 1, 7
- Extend to 6-8 weeks for osteomyelitis 1, 7
Critical Pitfalls to Avoid
- Do not administer vancomycin after dialysis as this prolongs treatment time and reduces patient acceptance; administration during the last hour is preferred 5, 3
- Do not use fixed 1000 mg doses every 5-7 days as this results in subtherapeutic levels in 16.3-41.67% of patients, particularly with high-flux membranes 4
- Do not rely on post-dialysis or pre-second dialysis concentrations for initial dosing decisions as these are consistently subtherapeutic 4
- Do not attempt catheter salvage for S. aureus, Pseudomonas, or Candida CRBSI as this significantly worsens outcomes 1