6 - Infective Endocarditis Flashcards
What is the incidence of infective endocarditis ?
- 2-6 cases per 100,000 population
- 1 per 1000 hospitalizations
Gram positive cocci in clumps = ?
staph
Gram positive cocci in chains = ?
strep
What are the most likely pathogens in a native valve endocarditis?
S. aureus (35%)
Strep (35%)
Enterococcus (10%)
What are the most likely pathogens in a prosthetic valve endocarditis ?
S. epidermidis (45%) S. aureus (20%) Fungal (10%) Enterococcus (10%) GNB (10%)
What are the most likely pathogens in a HCA (health care associated) endocarditis?
S. aureus (45%)
Enterococcus (15%)
S. epidermis (15%)
Streptococcus (10%)
Infective Endocarditis:
70% of cases associated with what 2 bugs?
- staphylococcus
- streptococcus
What are some risk factors for infective endocarditis?
- over 60 yo
- male
- bacteremia (intravascular catheter, IVDU)
- dialysis, diabetes, immunocompromised
- poor dentation
- prosthetic valve
- prior infective endocarditis
- congenital heart disease
- valvular heart disease
If they are at risk for infective, endocarditis, give an example of a scenario when antimicrobial prophylaxis is important?
dental procedures !
Why is there controversy around antimicrobial prophylaxis to prevent IE ?
1) Bacteremia is more likely spontaneous than procedure-related.
2) Oral health hygiene is important in prevention.
3) AP with 100% compliance likely to prevent small number of cases.
4) Antimicrobial-related adverse events may exceed benefits.
5) AP should be limited to dental procedures in highest-risk patients.
What are the highest-risk cardiac conditions for IE ?
- prosthetic heart valves (400x)
- prior endocarditis (400x)
- unrepaired congenital heart disease, or incompletely repaired with residual defects at prosthetic patches/devices , or completely repaired with prosthetic materials for 6 months
- cardiac transplants with valve dysfunction (valvulopathy)
What types of dental procedures cause bacteremia with IE pathogens ?
- procedures manipulating gingival tissue, peri-apical region of teeth, or perforation of oral mucosa (not injections, radiographs)
ex. extractions (where the gums are cut out)
**these patients should get AP to prevent IE
What is the 1st line antimicrobial for AP to prevent IE?
Include dose
Adults:
Amoxicillin 2g 1 hr prior to procedure
Children:
Amoxicillin 50mg/kg 1 hr prior to procedure
What is an alternative?
Include dose
Cephalexin or Cefadroxil
Adults:
2g 1 hr prior to procedure
Children:
50mg/kg 1 hr prior to procedure
What are alternatives for Severe beta lactam allergy? (3)
Include dose
Azithromycin/Clarithromycin :
Adults:
500 mg 1 hr prior
Children:
15 mg/kg 1 hr prior
Clindamycin:
Adults:
600 mg 1 hr prior
Children:
20 mg/kg 1 hr prior
For surgery involving respiratory, GI and GU tracts, ________ IV provides IE prophylaxis for staphylococcus and streptococcus
Cefazolin
For surgery involving GI and GU tracts, adding ______ provides IE prophylaxis for enterococcus
Ampicillin
What is enterococcus covered by?
it is covered by penicillins, not by cephalosporins
*Cefazolin will cover Staph and Strep. If you’re worried about Enterococcus, need to add a penicillin !
What mortality rates are associated with IE?
15-25% mortality (40% at 5 years)
>50% for fungal >20% for left-sided S. aureus 20% for enterococcus 10% for streptococcus <5% for right-sided S. aureus associated with IVDU
What is the clinical presentation of IE?
- fever (>75%)
- leukocytosis, anemia, elevated ESR and CRP
- malaise, anorexia, weight loss (50%)
- regurgitant murmur in most cases, new murmur (35%)
- new/worsening heart failure
- skin/mucosal lesions (50%)
- pulmonary emboli, TIA/stroke, renal failure (hematuria), splenomegaly
Subacute, indolent = ______
streptococcus
Acute, invasive = ________
S. aureus
What means Definite IE ?
2 major criteria OR 1 major + 3 minor OR 5 minor
What means Possible IE ?
1 major + 1 minor
OR
3 minor criteria
List Major Criteria
- blood culture for IE pathogen (x 2 of 3 draws from different sites > 1 hr apart)
- serology for Coxiella burneatii (Q fever)
- echocardiogram for IE (vegetation, abscess)
List Minor Criteria
- predisposition, predisposing heart conditions, IVDU
- temperature > 38 degrees C
- vascular phenomenon (trunk, buccal, conjunctival petechia, splinter hemorrhages, Janeway lesions)
- immunologic phenomenon (glomerular nephritis, Osler’s nodes, Roth’s spots)
- microbiological data that does not meet major criteria
What are Janeway lesions ?
little blood bursts under the skin
What are Osler’s nodes?
when patients have endocarditis, there tends to be an immunologic reaction so antibodies deposit in skin
What are Roth’s spots ?
hemorrhagic lesions in rent bc of emboli
What are the principles of antimicrobial therapy for ACTUALLY TREATING infective endocarditis ??
1) High-dose, IV therapy for plasma concentrations that sufficiently penetrate vegetation (clot)
2) Bactericidal against high-densities of bacteria with low metabolism and stationary growth phase
(cannot use static drugs)
3) Prolonged duration to sterilize vegetation (and then over time the vegetation will be resorbed)
List some of the streptococci species that are associated with IE ?
S. mitis
S. sangiunis
S. mutans
S. gallolyticus
Why are prosthetic valve endocarditis harder to treat ?
biofilm
Streptococcal IE therapy:
Pen-S:
What is the treatment for NVE ?
4w pen 12-18 MU/day (dosed Q4H)
or
4w Ceftriax 2 g Q24H
Streptococcal IE therapy:
Pen-S:
What is the treatment for NVE ?
(severe B lactam allergy)
4w Vanco 15 mg/kg Q12H
Streptococcal IE therapy:
Pen-S:
What is the treatment for NVE ? (uncomplicated, <5mm, no CV risks, no embolic events, treatment response)
2w Pen (12-18 MU/day or dosed Q4H)
+/-
Gent 3 mg/kg Q24H
(gent is being used for synergy)
OR
2w Ceftriax + Gent
Streptococcal IE therapy:
Pen-S:
What is the treatment for PVE ?
6w Pen 24 MU/day or dosed Q4H
+/-
2w Gent 3mg/kg Q24H
OR
6w Ceftriax + 2w Gent
Streptococcal IE therapy:
Pen-S:
What is the treatment for PVE ? (severe B lactam allergy)
6w Vanco
Streptococcal IE therapy:
Pen-RR:
What is the treatment for NVE ?
4w Pen 24 MU/day or dosed Q4H
+
2w Gent 3mg/kg Q24H
OR
4w Ceftriax + 2w Gent
Streptococcal IE therapy:
Pen-RR:
What is the treatment for NVE ?
(severe B lactam allergy)
4w Vanco
Streptococcal IE therapy:
Pen-RR:
What is the treatment for PVE ?
6w Pen 24 MU/day or dosed Q4H
+
Gent 3/mg/kgk Q24H
OR
6w Ceftriax + Gent
Streptococcal IE therapy:
Pen-RR:
What is the treatment for PVE ?
(severe B lactam allergy)
6w Vanco
Streptococcal IE therapy:
Pen-R:
What is the treatment for NVE ?
4-6w Pen 18-30 MU/day or dosed Q4H \+ Gent 3 mg/kg/day in 2-3 doses OR 4-6 weeks Ceftriax + Gent
Streptococcal IE therapy:
Pen-R:
What is the treatment for NVE ?
(severe B lactam allergy)
4-6 weeks vanco
Streptococcal IE therapy:
Pen-R:
What is the treatment for PVE ?
6w Pen 24 MU/day or dosed Q4H
+
Gent 3 mg/kg/day in 2-3 doses
OR
6w Ceftriax + Gent
Streptococcal IE therapy:
Pen-R:
What is the treatment for PVE ?
(severe B lactam allergy)
6 weeks Vanco
How is IE different in patients with history of IVDU ?
- Often without pre-existing valvular disease
- Tricuspid valve in > 50% of cases
- S. aureus in 60-80% of cases
- Response favourable for S. aureus but poor for GNB and fungal infections
Endocarditis in IVDU will mainly be on the ____ side
RIGHT
Endocarditis in non-IVDU will mainly be on the _____ side
LEFT
Staphylococcal IE Therapy:
What is the treatment for MSSA or MSSE? (NVE)
6w Cloxacillin 2g Q24H
OR
2w Clox (uncomplicated tricuspid associated with IVDU)
Staphylococcal IE Therapy:
What is the treatment for MSSA or MSSE? (NVE)
for Severe B lactam allergy
6w Vanco 15 mg/kg q12h
6w Dapto > 8 mg/kg q24h
Staphylococcal IE Therapy:
What is the treatment for MSSA or MSSE? (PVE)
> 6 weeks Clox \+ Rifampin 300 mg PO q8h \+ 2w Gent 3 mg/kg/day in 2-3 doses
Staphylococcal IE Therapy:
What is the treatment for MRSA or MRSE? (NVE)
6 w Vanco 15 mg/kg q12h
Staphylococcal IE Therapy:
What is the treatment for MRSA or MRSE? (NVE)
*Alternative
6w Dapto
Staphylococcal IE Therapy:
What is the treatment for MRSA or MRSE? (PVE)
>6 weeks Vanco \+ Rifampin 300 mg PO q8h \+ 2w Gent 3 mg/kg/day in 2-3 doses
Gent is for synergy against ______
Strep
Rifampin is for synergy against ______
Staph
***These 6 week time frames are from the time you get a negative blood culture back.
So if you start them on this regimen, then 1 week in, you get negative blood culture, you will have ___ weeks total of treatment
7
Expected response for treating IE?
clinical improvement within 3-7 days
When should we repeat blood cultures ?
Every 2 days, for microbial response by:
- 2 days for streptococci and HACEK infections
- 3 days for B lactase against S. aureus
- 5 days for Vanco against S. aureus (Vanco is a slow killer)
____% of cases require surgery
25-30
If removed valve tissue is culture negative, what is the duration of antimicrobial therapy ?
complete full course of effective antimicrobial therapy including preoperative therapy
If perivalvular abscess or removed valve tissue is culture positive, what is the duration of antimicrobial therapy?
re-initiate and complete full course of antimicrobial therapy after surgery
