Exam 4 lecture 2 Flashcards
What is the most common pathogen with regard to bacteremia
Staph aureus (I.e the name SAB- Staph aureus bacteremia)
blood culture significance in SAB
Blood cultures are always clinically significant regardless of number of positive blood cultures.
Repeat blood culture sets q 48-72 hrs until negative)
Other than blood cultures, what diagnostic evaluations are performed in SAB and why?
-Echocardiograph- all patients with SAB
-TEE (transesophageal echocardiograph) performed after TTE, which is performed first (preferred for MRSA)
What if urine cultures are positive for s. aureus
S aureus is NOT a common organism in UTIs.
Prevalence of S aureus becteriuria in pts with SAB is 8-40%.
Translocation of S aureus from blood to urine
in patients with bacteremia, describe catheter and prosthetic device management
S aureus may colonize and infect metal, plastic surfaces. Cosnider all IV catheters and prosthetic devices to be infected in patients with SAB
- attempt to remove all prosthetic devices to avoid risk of relapse.
In management of SAB in pts with catheter and prosthetic device management, what should we do if unable to remove catheter
add rifampin, may need long term suppressive therapy
replace catheters when blood cultures negative for 48-72 hrs
Empiric tx for SAB
vancomycin IV q 8-12 h
daptomycin 6-10 mg/kg IV q 24 h
MSSA bacteremia tx of choice
Nafcillin
oxacillin
cefazolin
goal target for vancomycin
400-600 AUC/MIC
tx of MRSA vacteremia
Vanc
dapto
limited data with ceftaroline
should we use rifampin or vanc or aminoglycosides with MSSA bacteremia
No, drug i/a, toxicity, mortality
how long to treat uncomplicated SAB
14 days of IV therapy from first negative blood culture
criteria for uncomplicated SAB
-Exclusion of endocarditis (negative TEE, TEE)
-No indwelling or implantable devices or prostheses (valves, prosthetic joints, grafts)
- No evidence of metastatic infection
- Patient defervesced (fever brokr, clinically improved) with 48-72 hrs after initiating IV therapy and removal of presumed focus on infection
- follow up blood cultures drawn 2-4 days after initiating IV therapy and removal of presumed focus on infection are negative
Must meet ALL criteria to be uncomplicated
Tx duration for cpmplicated SAB?
4 wks
Tx duration for complicated SAB with metastatic infection
6-8 weeks
PO or IV for SAB
IV always ONLY
highest risk streptococci organisms for bacteremia
viriduans and gallolyticus
What to use for bacteremia due to S. pyogenes, S agalactiae, S pneumoniae
penicillin IV-> high dose amoxicillin PO
For S pneumoniae- Ceftriaxone or penicillin if susceptible
What are the two enterococci that cause bacteremia and risk for endocarditis
E facealis
E faecium
Tx duration for E facealis and E facium
7 days
E faecialis bacteremia tx
Ampicillin 2 g Q4h
if allergic , vanc or dapto
E faecium bacteremia tx
If VanA and VanB negative, vancomycin
If VanA or VanB positive (VRE)- daptomycin or linezolid
gram negative bacteremia organsims? tx duration? treatment?
pseudomonas aeruginosa
7 days (not from first day of negative blood cultures, different from MRSA)
Piperacillin/tazobactam
carbopenem
imipenem
meropenem
Levofloxacin
is longer duration of therapy always better for bacteremia?
no shorter duration is preferred in uncomplicated disease
takeaway for blood cultures for S aureus bacteremia
Mandatory repeat blood cultures q48-72h until negative for S aureus, not needed for other bacteremia
empiric therapy for MRSA bacteremia
Vanc or dapto
MSSA tx of bacteremia
nafcillin, oxacillin, cefazolin
duration for uncomplicated bacteremia
7-10 days
what happens if bacteremia is left unltratedq
leads to endocarditis
Classic way to diagnose endocarditis? describe it
Duke criteria
2 major criteria, 1 major + 3 minors or 5 minor criteria= endocarditis
major criteria
major
- microbiological (positive blood cultures)
-Echocardiography and CT imaging
- evidence of endocarditisnduring cardiac surgery
Minor (not important for exam)
-patient history (valve, heart disease, inj drug use)
- clinical symptoms (fever, vascular, imaging)
endocarditis vs bacteremia tx duration
Endocarditis is invasive, takes weeks
duration of endocarditis (native valve, prosthetic valve)
4-6 wks
native valve- shorter duration
prosthetic valve longer duration
When are surgical interventions required for endocarditis
Persistent vegetation after systemic embolization
valve > 10 mm vegetation
For high penicillin susceptible NATIVE valve endocarditis with viridians and/or S gallolyticus, what is tx
Penicillin G IV or ceftriaxone- 4 wks
Pen G + Gentamycin- 4 wks
Ceftriaxone + Gentamycin- 4 wks
Vancomycin- 4 wks
When are each tx for native valve highly pen susceptible viridians/gallolyticus used?
pen G or ceftriaxone- Preferred in pts > 65 yrs or with renal dysfunction.
Pen G + Gentamycin- not in pts with cardiac abscess or crcl<20
WHat is the MIC of highly pen susceptible
MIC< or = 0.12
tx for penicillin relatively resistant NATIVE valve endocarditis with viridians strep and/or gallolyticus
Pen G IV 4 wks + Gent IV 2 wks
Ceftriaxone 4 wks + Gent 2 wks
Vanc 4 wks (only if unable to tolerate B lactam therapy)
What is another option for pen G + Gent in pen relatively resistant native valve endocarditis
Ampicillin IV q 4h
MIC for pen relatively resistant MIC
MIC>0.12 to < 0.5
Tx of pen susceptible prosthetic valve endocarditis for viridians/gallolyticus
Pen G 6 wks+/- gentamycin 2 wks
Ceftriaxone 6 wks +/- gent 2 wks
Vancomycin 6 wks
NOTICE how much longer prosthetic are than native
Alternative for prosthetic valve endocarditis pen susceptible viridians/gallolyticus
AVOID gentamycin if Crcl<30
Instead of ceftriaxone- ampicillin 2 g IV is reasonable alternative
For prosthetic valve endocarditis with pen resistant strep viridians/ gallolyticus, what are tx options
Pen G + gent- 6 wks (ampicillin is alternative)
Ceftriaxone + Gent- 6 wks
Vanc - 6 wks (if unable to tolerate B lactam therapy)
for oxacillin susceptible strains (MSSA), native valve endocarditis, what is tx of choice
nafcillin or oxacillin 6 wks (2 wks for uncomplicated right sided)
For pen allergic- cefazolin - 6 wks
Tx of oxacillin resistant (MRSA) native valve endocarditis
Vancomycin 6 wks
daptomycin 6 wks
fda approved drug for right sided endocarditis
daptomycin
MRSA alternative in endocarditis
ceftaroline if failed vanc or dapto (salvage therapy)
tx for prosthetic valve endocarditis for MSSA
nafcillin or oxacillin (6 wks)
+ rifampin (6 wks) + gentamycin (2 wks)
What to use for immediate type HS rxn to b lactams in prosthetic valve endocarditis in MSSA (oxicillin susceptible)? Non immediate?
Vanc
Non immediate- cefazolin
What to use to treat MRSA prosthetic valve endocarditis
Vanc (6 wks) + Rifampin (6 wks) + Gentamicin (2 wks)
how to treat e faecalis, e faecium native/prosthetic valve endocarditis if they are pen and gent susceptible
Ampicillin + Gent (4-6 wks)
Pen + Gent- 4-6 wks
Ampicilin + ceftriaxone - 6 wks
4 wks for native
6 wks for prosthetic
e faecalis, e faecium native/prosthetic valve endocarditis if they are pen and gent susceptible, what to use if CRCL< 50? > 50
> 50- pen + gent
Amp + ceftriaxone if < 50
e faecalis, e faecium native/prosthetic valve endocarditis if they are pen susceptible and aminoglycoside resistant
Ampicillin + Ceftriaxone 6 wks
e faecalis, e faecium native/prosthetic valve endocarditis if they are pen susceptible, streptomycin susceptible, gent resistant
Ampicillin + streptomycin 4-6 wks
pen + Streptomycin 4-6 wks
e faecalis, e faecium native/prosthetic valve endocarditis if they are unable to tolerate B lactam, but are vanc and aminoglycoside susceptible
Vanc + Gentamycin 6 wks
Same if intrinisc resistance to penicillin or B lactamase producer
e faecalis, e faecium native/prosthetic valve endocarditis if they are Vancomycin resistant (VRE), pen and aminoglycoside resistant
Daptomycin > 6 wks
linezolid > 6 wks
Valve replacement may be necessary
What are HACEK Organisms? How to tx native of prosthetic valve endocarditis
Ceftriaxone- 4-6 wks (preferred)
Ampicillin +/- sulbactam
Ciprofloxacin 4-6 wks
HACEK- gram negative in oral flora
what are some non hacek gram negative organisms that cause endocarditis? tx?
Rare- < 2 % of endocarditis cases
E coli and Pseudomonas aeruginosa
Combination of B lactams (penicillins, cephalosporins and carbapenems + aminoglycosides or fluoroquinolones for 6 wks)
what is culture negative endocarditis? what to treat?
imaging shows endocarditis, but culture is negative
cover for staph aureus, strep, aerobic gram negative bacilli (pseudomonas)
tx regimen for culture negative endocarditis
Vanc + Cefepime - 4-6 wks for acute (days onset)
Ampicillin/sulbactam + Vanc- 4-6 wks for subacute (weeks onset)
monitoring parameters for endocarditis
fever, blood cultures (blood cultures should beome negative within a week)
do patient cases on lecture march 12
