What is the recommended treatment regimen for a permacath infection using vancomycin and amikacin?

Treatment Regimen for Permacath Infection with Vancomycin and Amikacin

For permacath (tunneled dialysis catheter) infections, use vancomycin 20 mg/kg loading dose during the last hour of dialysis, then 500 mg during the last 30 minutes of each subsequent dialysis session, combined with gentamicin (or amikacin) 1 mg/kg (not exceeding 100 mg) after each dialysis session, along with antibiotic lock therapy using vancomycin 2.5-5.0 mg/mL with heparin. 1

Systemic Antibiotic Dosing

Vancomycin Dosing for Hemodialysis Patients

• Loading dose: 20 mg/kg infused during the last hour of the dialysis session 1
• Maintenance: 500 mg during the last 30 minutes of each subsequent dialysis session 1
• Target trough levels: 15-20 mcg/mL for serious infections including catheter-related bloodstream infections 1
• Monitor trough concentrations before the fourth or fifth dose at steady state 1

Amikacin Dosing for Hemodialysis Patients

• Dose: 1 mg/kg after each dialysis session, not to exceed 100 mg 1
• Alternative: Gentamicin or tobramycin at same dosing 1
• Peak target: 25-35 mg/L 2
• Trough target: 4-8 mg/L 2
• Monitor closely for nephrotoxicity and ototoxicity, especially when combined with vancomycin 1

Antibiotic Lock Therapy (Critical Component)

Antibiotic lock therapy should be added to systemic antibiotics for catheter salvage. 1, 3

Lock Solution Preparation

• Vancomycin concentration: 2.5-5.0 mg/mL (5.0 mg/mL is more efficacious for biofilm eradication) 1
• Heparin: 2,500-5,000 IU/mL 1
• Gentamicin alternative: 1.0 mg/mL with 2,500 IU/mL heparin for gram-negative coverage 1

Lock Therapy Administration

• Instill the antibiotic lock solution into both lumens of the catheter in the exact volume of each lumen 3
• Dwell time: 24 hours between dialysis sessions 3
• Replace lock solution daily 3
• Continue for the entire duration of systemic antibiotic therapy 3

Treatment Duration and Monitoring

Duration

• Minimum: 2 weeks for uncomplicated catheter-related bloodstream infection 1
• Typical range: 13-24 days depending on clinical response and follow-up blood cultures 3
• Continue until blood cultures are negative and clinical signs resolve 3

Monitoring Requirements

• Blood cultures: Draw from both the catheter and peripheral vein before starting antibiotics 3
• Vancomycin levels: Trough before 4th-5th dose, target 15-20 mcg/mL 1
• Amikacin levels: Peak and trough monitoring if available, especially with high-dose therapy 1
• Renal function: Monitor creatinine closely; avoid other nephrotoxic agents 1
• Hepatic enzymes: Check for twofold increases (more common with vancomycin-containing regimens) 4
• Ototoxicity screening: Particularly important with aminoglycoside use 1

Empirical Coverage Rationale

This combination provides:

• Gram-positive coverage (including MRSA): Vancomycin 1
• Gram-negative coverage: Amikacin/gentamicin 1
• Biofilm penetration: Antibiotic lock therapy addresses organisms embedded in catheter biofilm 1

Common Pathogens in Permacath Infections

• Staphylococcus species (most common) 3
• Pseudomonas species 3
• Enterobacter species 3
• Streptococcus species 3

Catheter Management

Attempt catheter salvage with combined systemic and lock therapy before removal. 3

Indications for Catheter Removal

• Hemodynamic instability or septic shock 1
• Persistent bacteremia after 72 hours of appropriate therapy 1
• Fungal infection (Candida species) 1
• Tunnel or exit site infection with purulence 1

Success Rates

• Combined systemic antibiotics plus lock therapy: 90% catheter salvage rate 3
• Systemic antibiotics alone: 71% catheter salvage rate with 29% mortality 3

Important Caveats

• Red man syndrome: Can occur with vancomycin infusion; consider prolonging infusion time to 2 hours and premedication with antihistamine 1
• Nephrotoxicity risk: Significantly increased with vancomycin-aminoglycoside combination; avoid additional nephrotoxic agents 1
• Dialysis schedule: Maintain regular dialysis schedule throughout treatment 3
• Adjust for renal function: These recommendations are specific to hemodialysis patients; different dosing applies to patients with residual renal function 5, 6