What is the treatment approach for a suspected Calcium-Related Blood Stream (CRBS) infection?

Treatment of Catheter-Related Bloodstream Infection (CRBSI)

For suspected CRBSI, immediately obtain paired blood cultures from both the catheter and a peripheral vein before initiating empirical antimicrobial therapy, then remove the catheter if the patient has severe sepsis, S. aureus, Pseudomonas, Candida, or persistent bacteremia beyond 72 hours despite appropriate antibiotics. 1

Diagnostic Approach

Obtain paired blood cultures from the catheter and a peripheral vein before starting any antibiotics. 1, 2 A differential time to positivity (DTP) of ≥2 hours between catheter and peripheral samples is highly sensitive and specific for CRBSI. 1, 2 If peripheral access is impossible, draw two blood samples from different catheter lumens at different times. 2, 3

• Disinfect the catheter hub with alcohol, alcoholic chlorhexidine (>0.5%), or tincture of iodine before drawing cultures. 2, 4
• Day 1 of treatment duration is defined as the first day negative blood cultures are obtained. 1

Immediate Catheter Management Decision

Mandatory Catheter Removal 1

Remove the catheter immediately if ANY of the following are present:

• Severe sepsis, hypotension, or organ failure 1, 2
• S. aureus bacteremia (only 20% success rate with catheter salvage) 1
• Pseudomonas aeruginosa infection 1
• Candida species infection 1, 4
• Mycobacterial infection 1
• Suppurative thrombophlebitis or endocarditis 1
• Tunnel or pocket infection 4
• Persistent bacteremia >72 hours despite appropriate antimicrobial therapy 1

For short-term (non-tunneled) catheters, also remove for gram-negative bacilli, enterococci, fungi, and mycobacteria. 1, 3

Catheter Salvage May Be Attempted 1

Only in clinically stable patients with limited venous access and infections caused by:

• Coagulase-negative staphylococci 1, 2
• Corynebacterium jeikeium 1
• Acinetobacter baumannii 1
• Stenotrophomonas maltophilia 1

Requirements for salvage attempt: Use both systemic antibiotics AND antibiotic lock therapy, obtain repeat blood cultures at 72 hours, and remove catheter if cultures remain positive. 1

Empirical Antimicrobial Therapy

Gram-Positive Coverage 1

• Vancomycin is the first-line empirical agent in settings with elevated MRSA prevalence. 1, 3
• Switch to daptomycin if vancomycin MIC values >2 μg/mL or in institutions with high prevalence of such strains. 1
• Do NOT use linezolid empirically (only after proven bacteremia). 1, 3

Gram-Negative Coverage 1

Base selection on local antibiogram and severity:

• Fourth-generation cephalosporin, carbapenem, or β-lactam/β-lactamase combination ± aminoglycoside 1, 3
• Use combination therapy for neutropenic patients, severe sepsis, or known colonization with multidrug-resistant organisms like Pseudomonas. 1

Fungal Coverage 1

Empirical antifungal therapy is indicated for septic patients with:

• Total parenteral nutrition 1
• Prolonged broad-spectrum antibiotic use 1
• Hematologic malignancy 1
• Bone marrow or solid-organ transplant 1
• Femoral catheterization 1
• Candida colonization at multiple sites 1

Use an echinocandin (caspofungin, micafungin, anidulafungin) for empirical treatment. 1, 3 Fluconazole may be used only if no azole exposure in prior 3 months and low risk of C. krusei or C. glabrata. 1

Pathogen-Specific Treatment Duration

Coagulase-Negative Staphylococci 1, 2

• Catheter removed: 5-7 days of IV antibiotics 2
• Catheter retained: 10-14 days IV antibiotics PLUS antibiotic lock therapy 1, 2
• Remove catheter if persistent fever/bacteremia after these measures (occurs in 20% of cases). 1

S. aureus 1, 2

• Uncomplicated (catheter removed): Minimum 10-14 days IV antibiotics after catheter removal 1
• Complicated infections: 4-6 weeks of therapy 1, 2
• Perform transesophageal echocardiography (TEE) to rule out endocarditis in all S. aureus bacteremia cases. 2, 4
• Antibiotic options based on sensitivities: penicillin, first-generation cephalosporin, vancomycin, daptomycin, or linezolid. 1

Enterococcus 1

• Susceptible isolates: Ampicillin or vancomycin alone or with aminoglycoside 1
• Resistant isolates: Linezolid or daptomycin 1
• Catheter retained: 7-14 days IV treatment plus antibiotic lock therapy 1

Candida Species 1

• Mandatory catheter removal 1
• Continue antifungal therapy for 14 days after first negative blood culture and resolution of symptoms 1

Special Populations

Hemodialysis Patients 1

• Always remove catheter for S. aureus, Pseudomonas, or Candida infections. 1
• If absolutely no alternative sites exist, exchange over guidewire as salvage strategy (combined with antibiotics). 1
• A new long-term catheter can be placed once blood cultures are negative. 1
• Draw peripheral blood cultures from vessels NOT intended for future fistula creation (e.g., hand veins). 1

Pediatric Patients 1

• Indications for catheter removal are similar to adults unless no alternative access exists. 1
• Monitor closely with clinical evaluation and repeat blood cultures if catheter retained. 1
• Remove device if clinical deterioration or persistent/recurrent CRBSI occurs. 1

Critical Pitfalls to Avoid

• Never delay obtaining blood cultures before starting antibiotics - this complicates diagnosis and pathogen identification. 2, 3, 4
• Never attempt catheter salvage with S. aureus, Pseudomonas, or Candida - failure/delay increases mortality and hematogenous complications. 1, 2
• Do not routinely replace CVCs or perform guidewire exchanges to prevent infection - this does not reduce CRBSI rates and increases insertion complications. 1, 4
• Do not use linezolid empirically - reserve for proven infections only. 1, 3
• Do not ignore local antibiogram data - empirical gram-negative coverage must reflect institutional resistance patterns. 1, 3