Lecture 1 - Bloodstream Infections & Infective Endocarditis Flashcards
Most common Community Acquired Pathogen for infection
E.coli
S.aureus
Streptococcus
Most common Healthcare associated Pathogen for infection
Staphylococcus
Other gram neg
How to diagnose Blood stream infection
Blood cultures
Draw 2 sets of cultures -> 12hrs/5 days it turns positive -> after positive do stain/subculture & rapid diagnostics -> 18-24hr after subculture ID organism and start susceptibility test 0> 6-24hrs ID organism and susceptibility results
Gram + cocci clusters vs pairs/chains
Clusters = staph
Chain/pairs = strep/Enterococci
Primary infection
Direct introduction into bloodstream
Idiopathic, source unclear
Secondary infection
Translocation form other source of infection
Continual seeding from non-infected area
Empirc management of suspected sepsis
obtain >2 blood cultures
initial brand antimicrobial therapy, guided by suspected source
If no clear source of infection, empiric therapy is..
Broad gram + (MRSA) & Borad GNR & Anaerobes/Atypiclals/ Candida/Toxins maybe
Med specific monitoring Vanco
renal toxicity
Med specific monitoring Dapto
creatinine kinase
Med specific monitoring Linezolid
thrombocytopenia
2 reasons for treatment failure
inadequate coverage or source control
2 Gram + cocci in clusters
Staph aureus
Coagulase negative staph
Risk factors for S.aureus bacteremia
> 70yrs old
HD requirements, PICC lines, Urinary catheter
Foreign material
Immunosuppression
MRSA specific risk factors
Hospital / HC exposure
Recent IV ABX exposure
Injectable drug use
3 main agents for MRSA bacteria
Vanco = AUC/MIC 400-600
Dapto = 8mg/kg ABW
Linezolid = 600mg Q12h
Vancomycin tends to be used first, but none is better
MSSA Bacteria treatment
cefazolin 2g Q8H or oxacillin/nafcillin 2g Q4h
both better than vanco
Gram positive cocci in cluster, MRSA Txm =
Vanco
Dapto
Linezolid
Gram positive cocci in clusters, MSSA Txm =
Cefazolin
Nafcillin
Oxacillin
Gram positive cocci in pair/chain, Streptococci
PCN-S = penicillin G IV
PCN-R = ceftriaxone
Gram positive cocci in pair/chain, Enterococci
E.faecalis = ampicilin
E.faecium = variable
S. aureus txm duration
uncomplicated = 14 +/- 2 days
complicated 24-42 +/- 2 days, > 4wk most pts
Basic different between complicated and uncomplicated
pts who respond to therapy quickly and don’t have any other concerning site for infection = uncomplicated
other = complicated
most S.aureus is complicated
Coag Neg Staph txm Duration
Simple = 0-3 +/- 1 day
uncomplicated = 5 +/- 1 day
Complicated = 7-28 +/- 2 day
Pseudomonas Aeruginoas Risk Factors
Modifiable: immunosuppression, housing insecurity, IDU
non-modifiable: hospitalization, recent IV ABX use < 90 days, history of PsA
Empiric GNR Bacteremia Txm w/o ESBL history
Cefepime 2g Q8H
Ceftazidime 2g Q8H
Pip/Tazo 4.5g IV Q6h
Empiric GNR Bacteremia Txm w/ ESBL history
Meropenem 1g Q8H
Pts eligible for Oral Therapy ABX Gram -
Enterobacterales BSI
Afebrile & Hemodynamically stable for > 48hrs
Isolate susceptible to agents with reliable serum conc
Able to take oral meds
Pts eligible for 7 day treatment Gram -
enterobacterales BSI
Afebrile & Hemodynamically stable for >48hrs
Adequate source control
Unclear eligibility for 7 day therapy Gram -
PsA BSI
pts with immunocompromising condition/meds
Men with UTI
Short term catheter, uncomplicated CoNs
remove line and treat with systemic agents for 5-7 days
or
retain line and treat w/ lock therapy and systemic agents for 10-14 days
Short term catheter, complicated or any other organism
remove line and treat w/ systemic agents for > 7 days
Long term catheter, complicated, S.aureus, or Candida spp.
remove line and treat w/ systemic agents for > 7 days
Long term catheter, uncomplicated w/ other organism
remove line and treat w/ systemic agents for > 7 days
or
line salvage w/ lock therapy and systemic agent for > 7 days
Lock therapy
uses high conc but low volume of antimicrobial in line itself
sits in line for 24-48hrs
needs to be given W/ systemic therapy for treatment
Candidemia initial therapy
Echinocandin = Caspofungin or micofungin
alternative if not critically ill or low risk of resistance = fluconazole
Candidemia Definitive therapy
based on susceptibilities
different species have different breakpoints
Candidemia Txm duration
uncomplicated = 2 weeks
complicated = based on site of infection
Right side IE more common in…
IDU due to impure ingredient that damage right side of heart
Left side IE more common in…
non-IDU due to turbulent flow the damage left side of heart
General risk factors for Endocarditis
Hear structure abnormalities
Comorbidities - CKD, DM, HD
Prior infection - prior endocarditis, skin-soft tissue infection w/ DM
Patient factors - IDU, indwelling catheter, HD, devices, poor oral hygiene
Endocarditis immunologic reactions
Osler nodes = painful papules pads of toes/fingers
Roth spot = retinal infarct w/ surrounding hemorrhage
Endocarditis Thromboembolic complication
Janeway lesions = painless lesion on palms
Finger clubbing = long standing disease
Splinter hemorrhage = occurs in nail bed
Petechiae = painless lesions typically on trunk
Septic emboli = stroke or PE
Most common way to ID endocarditis
Blood cultures + Imaging
> 3 blood cultures
TTE (more specificity) 1st and then can do TEE (higher sensitivity)
Definitie Endocarditis using modified Duke Criteria
2 major, 1 major + > 3 minor and/or 5 minor criteria
Possible Endocarditis using modified Duke Criteria
1 major + 1 minor or 3 minor
Empiric therapy, Native valve Txm
Vanco + ceftriaxone
Empiric therapy, Prosthetic valve w/ <1 year of placement txm
Vanco + cefepime + rifampin + gentamicin
Empiric therapy, Prsthetic valve > 1 year of placement txm
Vanco + ceftriaxone
what group is S.bovis?
Viridians group strep
Pts ineligible for short 2 week treatment for VGS in Native valve PCN-S
known cardiac or extra-cardiac abscess
History of renal dysfunction/AKI, CrCl < 20
Impaired eight cranial nerve
Non-traditional sp (ie Gemella)
Gentamicin duration in therapy for VGS in Native value PCN-R?
add on only for 2 weeks, but course is for 4weeks
Typical Txm duration for native vs Prosthetic valve
4 weeks vs 6 weeks
Most common causes of IE
S.auerus and Coagulase Negative Staph
Why are rifampin and Gentamicin add ons for prosthetic valve?
to help penetrate biofilms potentially
Prophylaxis indications Endocarditis
dental procedures w/ perforation of oral mucosa or manipulation of gingival tissue
incision or biopsy of mucosa
Pts who are at high risk of adverse endocarditis outcomes
Prosthetic valve or prostheses from valve repair
history of infective endocarditis
Cardiac tranplan w/ valvulopathy
congenital HD, unreparired or repaired with retained foreign material
Common prophylaxis txm endocarditis
Amoxicillin PO
Cefazolin IV
Clindamycin if B-lactam allergy
