Therapeutics 3: Bloodstream/catheter-related infections (trinh)

Define catheter-related bloodstream infection (CRBSI)

bacteremia or fungemia in a patient with an intravascular device and > 1 positive peripheral blood culture, infection signs and symptoms, and no identifiable source

Define centra line-associated bloodstream infection (CLABSI)

primary BSI in patient that had a central line within the 48 hour period before BSI development

Uncomplicated infection:

- fever and BSI resolve

Complicated bloodstream infection:

-fever and BSI resolve > 72 hours after initiation of antimicrobials

Which catheter type has the highest risk of CRBSI?

non-tunneled central venous catheter

What is an extraluminal CRBSI?

migration of skin pathogens at insertion site

what is intraluminal CRBSI

migration from contamination of catheter hub

Listed microbes that creat biofilms (4)

Staph spp.

Pseudomonas

Enterococcus spp.

Candida spp.

What kind of microbe are the most common cause for a bloodstream infection?

coagulase-negative staph (16-31%)

-most are methicillin-resistant

Gram negative bacilli that can cause a bloodstream infection: (4)

klebsiella

e. coli

enterobacter spp.

pseudomonas

Risk factors for bloodstream infections

-multi-lumen device

- parenteral nutrition

- chemo

- immunosuppression

- long duration of vascular catheter use

CRBSI signs

- erythema, purulence, tenderness or pain around insertion site

- Phlebitis

Which of the following bacteria is/are the most common cause of catheter-related bloodstream infections?

A. Staphylococcus aureus

B. Escherichia coli

C. Coagulase-negative

staphylococci

D. Pseudomonas aeruginosa

E. Klebsiella pneumoniae

C. Coagulase-negatice staphylococci

T/F: For bloodstream/ catheter infections, ALWAYS obtain blood cultures prior to starting antibiotics

True

Definitive diagnosis for CRBSI (a lot)

Percutaneous blood sample AND catheter tip growing the same

organism (note that tip can only be cultured if catheter is removed)

OR

Blood sample obtained from peripheral vein AND catheter hub growing

the same organism

AND

3-fold higher microbial colony count from catheter hub sample

OR

Catheter hub sample positive ≥2 hours before peripheral vein sample

OR

two blood samples from different catheter lumens growing the same

organism

AND

3-fold higher microbial colony count in one sample than the other sample

T/F: Micrococcus spp. and Bacillus spp. from a single blood culture set is NOT indicative of a bloodstream infection

True; must be confirmed with 2 or more positive blood cultures from different sites

Other potential contaminants that would lead to getting greater or equal to 2 blood cultures from different sites

coagulase-negative staph, corynebacterium

Catheter removal considerations for long-term catheter

if infected with s. aureus, pseudomonas, fungi, or mycobacteria

-severe sepsis

-suppurative thrombophlebitis

- infective endocarditis

- positive blood cultures > 72 hours despite appropriate antibiotics

Catheter removal considerationsfor short-term catheters

Infection with S. aureus, Enterococcus spp., gram-negative bacilli, fungi, or mycobacteria

T/F: For bloodstream infections, ALWAYS use an antibiotic with activity agaisnt MRSA and coagulase-negative staph (also usually methicillin-resistant)

True

Empiric gram-negative antibiotics considerations/ risk factors

- hemodialysis CRBSI

- femoral catheter CRBSI

- critiacally ill

- neutropenia (ANC < 500)

- known colonization with or concurrent infection by gram- negative

Empiric Candida spp. risk factors/considerations

- critically ill

- sepsis with any of the following:

parenteral nutrition

prolonged broad-spectrum use

hematologic malignancy

bone marrow transplant

solid organ transplant

known colonization with Candida at multiple sites

Which of the following is NOT an indication for empiric gram-negative coverage in patients with suspected CRBSI?

A. Hemodialysis catheter

B. Femoral catheter

C. Septic shock

D. Neutropenia

E. Hospitalization ≥ 48 hours

before CRBSI onset

E. Hospitalization ≥ 48 hours before CRBSI onset

FIRST LINE for gram-positive bacteria in blood infection

Vancomycin

Alternative empirics to vancomycin for gram-positive blood stream infections

daptomycin

- only used if cannot tolerate vanco OR VRE

Empiric antimicrobial options for Gram-negative bloodstream infections

B-lactams

- cefepime, impenem, meropenem, zosyn

Fluoroquinolones

- cipro, levo

Aminoglycosides

- amikacin gentamicin, tobramycin

Empiric antimicrobial options for Candida spp.

Echinocandins

- anidulafungin, caspofungin, micafungin

Slide 28?

DIRECTED therapy- gram negative

If enterobacterales,no resistance = ceftriaxone

If pseudomonas = cefepime, meropenem, zosyn

Directed therapy alternative to echinocandins for Candida infection

fluconazole

Duration of therapy for uncomplicated removed catheter coagulase- neg staph

5-7 days

Duration of therapy for uncomplicated removed catheter enterococcus spp. or gram negative bacilli

7-14 days

Duration of therapy for uncomplicated removed catheter candida spp. infection

14 days

Duration of therapy for uncomplicated retained catheter coagulase-neg staph

10-14 days + antibiotic lock

Duration of therapy for uncomplicated retained catheter s. aureus

4 weeks + antibiotic lock

Duration of therapy for uncomplicated retained catheter enterococcus spp.

7-14 days + antibiotic lock

Duration of therapy for uncomplicated retained catheter gram negative bacilli

10-14 days + antibiotic lock

What defines BSI clearance

the first negative blood culture after which no further positive culture is documented

T/F: Date of BSI clearnace is the first day of antibiotic therapy when counting days

true

What is antimicrobial Lock therapy

when you instill a high concentration of an antimicrobial into the lumen mixed with heparin

- cefazolin, ceftazidime, vanco

When is antimicrobial lock therapy indicated?

for patients with CRBSI without entry site or tunnel infection, involving long-term catheters fro whom catheter salvage is necessary

How long should the antimicrobial dwell in antimicrobial lock therapy?

>12 hours per day but

Which of the following patients requires antibiotic lock therapy?

A. A patient with MRSA CRBSI who had infected catheter removed

B. A patient with P. aeruginosa CRBSI who had infected catheter removed

C. A patient with VRE CRBSI who did not have infected catheter removed

D. A patient with S. epidermidis CRBSI who had infected catheter removed

E. All patients with CRBSI should receive antibiotic lock therapy

C. A patient with VRE CRBSI who did not have infected catheter removed