Day 4 - Bacteremia

Gram Stains, Common Organisms and Empiric Antibiotics
All patients with bacteremia should have an examination to identify the source

Gram Positive Cocci in Groups

• Coagulase Positive - Staphylococcus Aureus (Can be MSSA or MRSA)

• Coagulase Negative - Staphylococcus sp. Not aureus

Empiric Antibiotics: Cloxacillin 2g IV q4h, Cefazolin 2g IV q8h or Vancomycin 15-20mg IV x 1 loading dose, then 1g IV BID

Gram Positive Cocci in Chains

• Streptococcus sp.

• Enterococcus sp.

Empiric Antibiotics: Ceftriaxone 2g IV q24h

Gram Positive Bacilli - Generally skin organisms

• Clostridium sp.

• Bacillus sp. (ie - Bacillus Anthracis, Bacillus Cereus)

Empiric Antibiotics: None if stable, redraw blood cultures to r/o contamination

Gram Negative Bacilli

• E. Coli sp.

• Klebsiella sp.

• Pseudomonas sp.

Empiric Antibiotics: Ceftriaxone 2g IV q24h
Prior ESBL Positivity: Meropenem 1g IV q8h or Ertapenem 1g IV q24h
Prior Pseudomonas: Tazocin 4.5g IV q6h

Gram Negative Cocci

• Neisseria sp.

Empiric Antibiotics: Ceftriaxone 2g IV q24h

Yeast

• Candida sp.

Empiric Antibiotics: Caspofungin 70mg IV x 1 loading dose, then 50mg IV daily or Anidulafungin 200mg IV x1 loading dose, then 100mg IV daily

Duration of Treatment for Uncomplicated Infections

• Gram positive bacteremia - generally 14 days

• Gram negative bacteremia - generally 7-10 days

Frequently Asked Questions:

1. My patient has a central line - how do I know if it is a central line infection vs native bloodstream infection?

   • Line infection vs peripheral infection can be distinguished using time to positivity. Blood cultures should be drawn from the central line and the peripheral site at the SAME time. Time to positivity < 120 min - Peripheral Infection. Time to positivity > 120 min - Central line infection.

2. Do all patients require echocardiogram to rule out endocarditis?

   • Only patients with organisms causing endocarditis require echocardiograms

3. Is coagulase negative staphylococcus always a contaminant?

   • No! Multiple positive cultures for CNST should be taken seriously. Generally CNST requires treatment with vancomycin. Note of any indwelling devices, implants or hardware should be made to ensure that they do not have

4. Do I need to get an infectious disease consult?

   • Patients with Staph. Aureus bacteremia have been shown to have better outcomes with mandatory ID consultation.

5. What about neutropenic patients?

   • Neutropenic patients should be treated according to febrile neutropenia guidelines and risk assessment.