Catheter-Related Bloodstream Infection

Bloodstream

Patient + scenario modifiers

Patient

Clinical scenario / source

Annotations only — chart still shows the full chemistry of each drug.

1. Clinical Syndrome

CLABSI (CDC surveillance definition): laboratory-confirmed bloodstream infection in a patient with a central line in place ≥2 days, without another identifiable source.

CRBSI (IDSA clinical definition, more stringent): bacteremia/fungemia in patient with intravascular catheter + clinical signs of infection + no other apparent source + one of: positive catheter tip culture (≥15 CFU semi-quantitative) with same organism as blood, OR ≥2× higher CFU from catheter-drawn blood than peripheral, OR differential time-to-positivity ≥2 h (catheter culture flags positive ≥2 h before peripheral).

Excludes: secondary bacteremia from another source (pneumonia, UTI, intra-abdominal), contaminant (single positive culture of skin organism without clinical correlate), pocket / tunnel infection (local management ± systemic abx).

2. Pathogens

Consider the patient: Line type (peripheral IV, midline, PICC, non-tunneled CVC, tunneled CVC, port), duration (recent vs prolonged), TPN exposure (raises Candida risk), immunocompromise (broader empirics + fungal), recent broad-spectrum abx (MDRO, fungi).

Consider the case: Severity (sepsis vs simple bacteremia), distant complications (endocarditis, septic emboli, persistent bacteremia), salvageable vs non-salvageable line (S. aureus / Candida / mycobacteria / persistent bacteremia → remove always; CoNS / select GNR → salvage attempt possible for tunneled lines).

Common

- Coagulase-Negative Staphylococci
  Most common CLABSI pathogen. Confirm with ≥2 positive sets + clinical correlate before treating — single positive often contaminant.
- Staphylococcus aureus (MSSA)
  Always significant. Mandates line removal, TEE, 14-day minimum therapy, evaluation for metastatic infection.
- Staphylococcus aureus (MRSA)
  Same management as MSSA but vancomycin-based regimen. Higher rate of complications.
- Candida albicans
  TPN exposure, prolonged broad-spectrum abx, immunocompromise. Always remove line, ophtho exam, 14 days from first negative.
- Enterococcus faecalis
  Often biofilm-associated. Consider underlying biliary or GU source if recurrent.

Less common

- Pseudomonas aeruginosa
  Burn ICU, prolonged hospitalization, neutropenia, femoral lines.
- Klebsiella pneumoniae
  Healthcare-associated; ESBL risk if prior abx exposure.
- Candida glabrata (Nakaseomyces glabratus)
  Fluconazole resistance common — echinocandin first-line empiric.
- Enterococcus faecium (VRE)
  Liver transplant, oncology, prolonged hospitalization.

3. Empiric Therapy

Tier	First choice	Alternatives	Duration	Comments
Admitted to ward	load + AUC-guided · — · IV · Empiric — narrow when cultures back	6–8 mg/kg · q24h · IV Alternative if vanco intolerance or MIC creep.	Empiric until organism identified; final duration is organism-dependent	Stable patient, no septic shock, no neutropenia. Vanc covers MRSA, CoNS, MSSA, enterococcus empirically. Add GNR coverage if neutropenic / immunocompromised / femoral line.
Admitted to ICU	load + AUC-guided · — · IV 2 g · q8h · IV · Empiric GNR coverage	Vanc + pip-tazo load + AUC vanc; 4.5 g pip-tazo q6h · — · IV Alternative if anaerobe coverage also desired (e.g., suspected gut translocation).	Empiric until organism identified	Septic / unstable patient. Covers MRSA + GNR including Pseudomonas. Add empiric echinocandin if Candida risk factors (TPN, multifocal colonization, recent abdominal surgery, prolonged broad abx).
ICU — Pseudomonas risk	load + AUC-guided · — · IV 2 g · q8h · IV 100 mg · q24h · IV Empiric antifungal — adjust to fluconazole step-down if C. albicans susceptible.	1 g · q8h · IV If ESBL risk or carbapenem-sparing not feasible.	Empiric until organism identified; antifungal continues 14 days from first negative if Candida grows	Septic shock + immunocompromise / TPN / prior broad abx. Echinocandin > fluconazole empiric — covers C. glabrata, C. krusei.

Add coverage if:

MRSA coverage

Healthcare-associated
Known MRSA colonization
Severe disease

Add:

load + AUC-guided · — · IV

Pseudomonas coverage

Neutropenia
Burn ICU
Femoral line
Prolonged hospitalization
Recent broad-spectrum abx

Add:

2 g · q8h · IV
Or pip-tazo / meropenem.

Candida coverage

TPN exposure
Multifocal Candida colonization
Recent abdominal surgery (esp upper GI)
Prolonged broad-spectrum abx
Hemodialysis catheter
Septic shock without clear bacterial source

Add:

100 mg · q24h · IV
Echinocandin preferred empiric — covers non-albicans. Step down to fluconazole if C. albicans susceptible.

ESBL coverage

Prior ESBL isolate
Recent broad-spectrum abx
Healthcare-associated

Add:

1 g · q8h · IV
Or ertapenem if not septic.

4. Directed Therapy

S. aureus (MSSA or MRSA):

Always remove line (no salvage attempts).
TEE (sensitivity for IE in S. aureus bacteremia ~90%; TTE inadequate).
Ophthalmology consult (endogenous endophthalmitis).
14 days minimum from first negative blood culture (uncomplicated SAB criteria); 4–6 weeks if endocarditis, abscess, persistent bacteremia, prosthetic device.
MSSA → nafcillin 2 g q4h or cefazolin 2 g q8h.
MRSA → vancomycin AUC-guided or daptomycin 8–10 mg/kg.

CoNS:

Distinguish pathogen (≥2 sets, clinical syndrome, biofilm-prone device) from contaminant.
Pathogenic: line removal + vancomycin × 5–7 days from first negative culture.
Tunneled-line salvage: systemic abx + antibiotic lock therapy (vancomycin lock) × 10–14 days if no complications.
S. lugdunensis is the exception — treat like S. aureus.

Candida:

Always remove line.
Ophthalmology exam within 1 week (endophthalmitis).
Echocardiogram if persistent fungemia or pre-existing valve disease.
Echinocandin first-line empiric; step down to fluconazole if C. albicans / parapsilosis susceptible.
14 days from first negative blood culture (uncomplicated candidemia).

Enterococcus:

E. faecalis (PCN-S): ampicillin 2 g q4h × 7–14 days.
E. faecium (often AmpR + VRE): daptomycin 8–10 mg/kg or linezolid 600 mg q12h.
Line removal usually required; salvage rare.

Gram-negative rods (E. coli, Klebsiella, Pseudomonas):

Line removal preferred; salvage possible for tunneled lines if susceptible isolate + antibiotic lock therapy + uncomplicated.
7–14 days from first negative; longer (4–6 weeks) if endovascular complication.

Mycobacteria, P. aeruginosa endocarditis, fungal endocarditis:

Remove line always. Long durations, surgical consult.

5. Monitoring

Resolution: repeat blood cultures q24–48 h until clear (essential — duration of therapy counted from first negative for S. aureus, fungi, GNR with high complication risk). Persistent bacteremia >72 h on appropriate abx → search for endovascular focus (TEE), abscess, retained device.

Imaging / specialty consults:

TEE for S. aureus, Candida, persistent bacteremia, prosthetic valve.
Ophthalmology for candidemia (every patient).
ID consult — required for S. aureus bacteremia per IDSA (improves outcomes).

Toxicity: vanc AUC + Cr; daptomycin CPK weekly; echinocandins LFTs; cefepime mental status in AKI.

Pearls

Line removal is the cornerstone for S. aureus and Candida — every time. Salvage attempts fail. For CoNS, distinguish contaminant (1/4 sets, no clinical signs) from pathogen (≥2 sets + device + syndrome). S. lugdunensis is the dangerous CoNS — treat like S. aureus. Antibiotic lock therapy for tunneled-line salvage (CoNS, susceptible GNR, enterococcus) — instill high-concentration antibiotic in line lumen for 12+ h/d × 10–14 days. Repeat blood cultures matter — duration counts from first negative for S. aureus, Candida. Differential time-to-positivity ≥2 h confirms line as source even without tip culture.

References

IDSA Catheter-Related Bloodstream Infection Guidelines (2009)
IDSA Candidiasis Guidelines (2016)
IDMP catheter-related BSI page