Bacteremia Flashcards
Staphylococcus aureus Bacteremia (SAB)
___ cause of community-acquired and hospital-acquired bacteremia
Mortality rates ∼20-40%
Treatment failure is relatively common in SAB, especially if due to ___
- Death within 30 days following treatment
- Persistent bacteremia > 10 days after initiation of appropriate therapy (some
recommend shorter duration of persistence)
- Recurrence of bacteremia within 60 days of discontinuing treatment
Staphylococcus aureus Bacteremia (SAB)
- leading
- MRSA
Repeat blood cultures q ___ - ___ h to document clearance
48-72
Clinical Stigmata of Endocarditis:
- osler’s nodes
- janeway lesions
- splinter hemorrhages
- petechiae
- roth spots
Diagnostic Evaluation in SAB
Blood cultures – always clinically significant regardless of number of positive blood cultures (1/4 vs. 4/4
bottles)
- Repeat blood cultures (2 sets) q ___ - ___ h until negative
___ – all patients with SAB!!
- Transthoracic echocardiography ( __ ) performed first
- Transesophageal echocardiography ( ___ ) usually performed after TTE (preferred for MRSA bacteremia)
- More ___ that TTE for identifying vegetation size/location
- 48-72
- Echocardiography
- TTE, TEE
- sensitive
Clinical Dilemna: What if Urine Cultures are Positive for S. aureus?
S. aureus is NOT a common
organism in UTIs
- ___ of S. aureus from
blood to urine due to hematogenous seeding and development of ___
- Translocation, microabscesses
Catheter and Prosthetic Device Management
Consider all IV catheters and prosthetic devices to be infected in patients with SAB until infection ruled out
- If unable to remove, may add ___ and may need long-term suppressive therapy
Catheter management
- Short term catheters – remove ASAP
- Long-term catheters – remove unless major contraindication
- Replace catheters when blood cultures ___ for 48-72 hours
- rifampin
- negative
Empiric Treatment of S. aureus bacteremia
Empirically cover MSSA and MRSA (rapid diagnostics)
- ___ 15-20 mg/kg IV q8-12h
- ___ 6-10 mg/kg IV q24h
- same for MRSA treatment
Addition of gentamicin or rifampin to vancomycin is not recommended
Addition of MSSA-specific agent to vancomycin??
- Favored by some clinicians in patients with highest risk of mortality (severe sepsis, probable endocarditis,
presence of prosthetic or intravascular device)
- vancomycin
- daptomycin
Treatment of Methicillin Sensitive S. aureus (MSSA) Bacteremia
- ___ 2 grams IV q4h
- ___ 2 grams IV q4h
- ___ 2 grams IV q8h
do not do vancomycin, or combine with rifampin or aminoglycoside
- nafcillin
- oxacillin
- cefazolin
Clinical Dilemma: Cefazolin vs. Anti-Staph PCNs in MSSA Bacteremia
___ better basically
cefazolin
Combination Therapy for SAB: Clinical Data
- Shorter durations of bacteremia with patients on vancomycin and ___ combo
- ___ plus vancomycin or dapto used as salvage therapy for refractory patients
It may be reasonable to employ combo therapy with a PBP-1 active β-lactam or ceftaroline with vancomycin or daptomycin early in MRSA bacteremia treatment course, especially in patients at highest risk of treatment failure and death
- B-lactam
- Ceftaroline
Duration of Treatment
- Uncomplicated SAB – ___ days of IV therapy from first negative blood culture
- Complicated SAB - __ weeks
- Complicated SAB with metastatic infection - __ - __ weeks
Current recommendations: ___ therapy for full duration
- 14
- 4
- 6-8
- IV
Uncomplicated SAB
must meet all criteria
- Exclusion of endocarditis (negative TTE, TEE)
- No indwelling or implantable devices or prostheses (prosthetic heart valve, pacemaker, prosthetic joints, vascular grafts, etc).
- Follow-up blood cultures drawn 2-4 days after initiating IV therapy and removal of the presumed focus on infection are negative.
- Patient defervesced with 48-72 hours after initiating IV therapy and removal of the presumed focus on nfection
- No evidence of metastatic infection
Prognosis in SAB
Presence of prosthetic material or devices ___ risk of relapse
Mortality rates – 20-40%
increases
Bacteremia Due to Other Gram-Positive Cocci
risk of endocarditis with varying streptococci
- Highest risk: ___ , Streptococcus gallolyticus
- Lowest risk: S. agalactiae, S. pyogenes, S. pneumoniae
Treatment duration: ___ days (IV → PO)
* S. pyogenes, S. agalactiae – penicillin IV (q4h or CI) → high dose amoxicillin PO
* S. pneumoniae – ceftriaxone or penicillin (if susceptible)
- viridans streptococci
- 14
Bacteremia Due to Other Gram-Positive Cocci
Treatment duration: ___ days
E. faecalis
- ___ 2 g q4h or 12 g CI (majority are susceptible);
- If amp-R or β-lactam allergy – ___ or daptomycin
E. faecium
- If vanA and vanB negative – vancomycin
- If vanA or vanB positive (VRE) – ___ 10 mg/kg/d, ___
7
- ampicillin, vanc
- dapto, linezolid
Treatment of Uncomplicated Gram-Negative Bacteremia
In general, treatment duration is ___ days
- Total days of therapy; not from first day of negative blood cultures
- Do not always have to repeat blood cultures (Different than S. aureus)
IV → PO when clinically improved and able to take PO
- PO – frequently TMP/SMZ, FQ, or β-lactam
Take home point: Longer is not always better. ___ days of therapy had comparable outcomes as compared to 14 days in patients with uncomplicated gram-negative bacteremia
- 7, 7
duration
this was said like 5 times in the gram negative section
Take home point: Longer
duration of therapy is not
always better
Antibiotic Therapy for P. aeruginosa Bacteremia
Short course (median 9 days) vs. long course (median 16 days)
trial: Patients in ___ course group spent 4 fewer days in the hospital
short
Clinical Pearls & Key Takeaways
- Always determine the ___ of bacteremia and assess for ___ complications
- Mandatory repeat blood cultures q ___ - ___ h until negative for S. aureus, usually not needed for other bacteremia
- ID consultation reduces mortality and improves outcomes (always consult ID!)
- Empiric therapy for MRSA: ___ (AUC-guided dosing) or ___ (higher dose in severe infections)
- MSSA treatment: Beta-lactams ( ___ , ___ , and ___ ) are superior to vancomycin
- ___ treatment durations (7-10 days) are effective for most cases of bacteremia including uncomplicated Gram-
___ bacteremia - Step-down to oral antibiotics is emerging as a viable option in select cases, but is not yet the gold standard
- source, metastatic
- 48-72
- vanc, dapto
- nafcillin, oxacillin, cefazolin
- shorter, negatice
