Infective Endocarditis Flashcards
Acute Endocarditis def (associated with what bacteria? Involve which valve? Mortality in how long?
Fulminating form; associated with high fevers and systemic toxicity (e.g., S. aureus, S. pyogenes, S. pneumoniae, or Neisseria gonorrhoeae) .
Mortality within days to weeks if untreated.
Generally involves aortic valve
Subacute Endocarditis def (associated with what bacteria? Involve which valve? Mortality in how long?
Indolent infection from less virulent organisms, often in pre-existing valvular disease (ex. Viridans group Streptococci, Enterococci, HACEK)
Mortality within 6-12 weeks if untreated
Generally involves mitral valve
Which valves are on right side?
Pulmonary and tricuspid valve
Which valves are on left side?
Mitral and aortic valve
Pathophysiology of infective endocarditis
Organisms adhere to fibrin-platelet clots that form at the site of damaged cardiac endothelium
Organisms activate monocytes to produce tissue factor activity (TFA) and cytokines
Coagulation pathway is activated causing further recruitment of platelets and growth of vegetation
S. aureus in infective endocarditis
Staphylococci
Most common cause of IE (rates continuing to increase)
Commonly seen with IVDA (often right-sided), DM, presence of skin disorders, or in patients with implanted cardiac devices
Highly virulent
S. epidermidis in infective endocarditis
Staphylococci
Ordinarily related to prosthetic valves or indwelling implanted cardiac devices
Viridans group streptococci (VGS) in infective endocarditis
Present in normal oral flora, skin, GI tract
Commonly in patients with underlying cardiac defects
E.g., rheumatic heart disease or mitral valve prolapse
Often community acquired infection
Enterococcus faecalis and Enterococcus faecium
Which one is more resistant? Found in normal flora
Enterococcus faecalis and Enterococcus faecium
Found in normal flora of the GI tract
Often seen in patients after patients after obstetric procedures or manipulation of genitourinary tract
HACEK Organisms in infective endocarditis
Slow growing, fastidious Gram-negative bacilli
Possible cause in culture-negative IE
Account for 5-10% of native valve endocarditis in non-IVDU patients
Haemophilus parainfluenzae OR aphrophilus Actinobacillus actinomycetemcomitans Cardiobacterum hominis Eikenella corrodens Kingella kingae
Clinical Presentation: Peripheral Manifestations of infective endocarditis
Osler Nodes Janeway Lesions Splinter Hemorrhages Petechiae Clubbing Roth Spots (eye exam)
Clinical Presentation: Lab findings
Anemia (normocytic, normochromic)
Thrombocytopenia
Leukocytosis (may be mild)
Elevated ESR/CRP
Clinical Presentation: Signs
Fever (>38 C)
Heart/Changing/New murmur
Vascular Embolic events
Pathologic Criteria: Definitive IE
Microorganism demonstrated by culture/sample of:
- Vegetation
- Embolized vegetation
- Intracardiac abscess speciness
Pathologic lesions:
-Histologic examination of vegetation or intracardiac abscess showing active IE
Clinical Criteria: Definitive IE
Modified Duke criteria:
- 2 major criteria
- 1 major criteria and 3 minor criteria
- 5 minor criteria
Clinical Criteria: Possible IE
Modified Duke criteria:
- 1 major and 1 minor criteria
- 3 minor criteria
Clinical Criteria: Rejected IE
- Alternative explanation for findings
- Resolutions of symptoms with ABx < 4 days
- No pathophysical evidence at surgery or autopsy with ABx < 4 days
- Does not meet criteria as described
Modified Duke Criteria: Major blood culture positive for IE
Typical organism from 2 blood cultures
Organisms consistent with IE from persistently positive blood culture:
- Culture has >=2 positive drawn >12 hours apart
- All of 3 or a majority of >4 cultures (with first and last drawn >1 apart)
Single positive blood culture for Coxiella burnetti or anti-phase IgG antibody tier >1:800
Modified Duke Criteria: Major evidence of endocardial involved
ECHO positive for IE
New valvular regurgitation (worsening/changing old murmur not sufficient )
Modified Duke Criteria: Minor
Predisposing heart condition or intravenous drug use
Fever >= 38.0 C (100.4 F)
Vascular phenomena: major arterial emboli, septic pulmonary infarcts, mycotic aneurysm, intracranial hemorrhage, conjunctival hemorrhage, Janeway lesion
Immunologic phenomena: glomerulonephritis, Osler’s nodes, Roth spots, rheumatoid factor
Positive blood culture not meeting major criterion as noted previously (Excluding single positive cultures for coagulase-negative staphylococci and organisms that do not cause endocarditis) or serologic evidence of active infection with organism consistent with infective endocarditis
Nonpharmacologic (FYI)
Typical indications for valve replacement:
Hemodynamic disturbances (CHF or valve dysfunction)
Positive blood cultures after 1 week of therapy
≥ 1 embolic event during first 2 weeks of therapy
Increase in vegetation size
Prosthetic valve endocarditis
Valve dehiscence, rupture, fistula, or abscess
Considerations when deciding therapy for Infective endocarditis
Valve type (native or prosthetic) Organism & susceptibilities Drug issues (e.g., allergy, renal function, etc.)
What drugs should be used for synergy in infective endocarditis?
Aminoglycosides (typically used for GNR activity) used at low doses for GPC synergy.
Gentamicin Dosing for Infective Endocarditis
1 mg/kg IV q8h - Option for ALL organisms -> REMEMBER THIS
3 mg/kg of IV q24h - Option for SOME organism
Monitoring for Gentamicin
Target peak for synergy 3-5 mg/L and trough < 1 mg/L
Obtain peak 30 mins after the end of a 30 min infusion (generally after 3rd dose)
Obtain trough (generally after 3rd dose) immediately before next dose
Penicillin MIC testing for which resistant
Viridans group streptococci
Utilized to guide treatment intensity
≤ 0.12 mcg/ml = sensitive
0.25 mcg/ml = relatively resistant to PCN
≥ 0.5 mcg/ml = fully resistant (uncommon)
Treatment for VGS and Streptococcus gallolyticus (bovis) – NVE
Highly Penicillin-sensitive Treatment Options (PCN MIC ≤ 0.12)
- PCN G 12-18 mU/d IV divided q4-6h or via continuous infusion (CI) x 4 wks (preferred if > 65 yo and poor candidates for AGs)
- Ceftriaxone 2 g IV/IM q24h x 4 wks (emerging DOC, esp. outpatients)
- PCN G or ceftriaxone as above x 2 wks PLUS gentamicin 3 mg/kg IV/IM q24h (or 1 mg/kg IV q8h) x 2 wks (shortest regimen; avoid if CrCl < 20 ml/min)
- Vancomycin 15 mg/kg IV q12h x 4 wks (penicillin/cephalosporin allergy)
Treatment for VGS and Streptococcus gallolyticus (bovis) – NVE
Relatively Penicillin-Resistant Treatment Options
(PCN MIC 0.25 mcg/ml)
- PCN G 24 mU/d IV divided q4-6h or via CI x 4 wks
PLUS - Gentamicin 3 mg/kg IV or IM q24h (or 1 mg/kg IV q8h) x 2 wks
- Ceftriaxone 2 g IV or IM q24h x 4 wks (if susceptible)
- Vancomycin 15 mg/kg IV q12h x 4 wks (penicillin/cephalosporin allergy)
Treatment: VGS and Streptococcus gallolyticus (bovis) – Prosthetic Valve or Other Prosthetic Material
- PCN G 24 mU/d divided q4-6h or via CI x 6 wks
OR
Ceftriaxone 2 g IV/IM q24h x 6 wks
EITHER, PLUS
Gentamicin 3 mg/kg IV/IM q24h (or 1 mg/kg IV q8h):
+ PCN MIC ≤ 0.12: Gent x 2 wks OPTIONAL; avoid if CrCl < 20 ml/min
+ PCN MIC > 0.12: Gent x 6 wks NEEDED in combination with PCN or ceftriaxone - Vancomycin 15 mg/kg IV q12h x 6 wks (severe PCN allergies)
Treatment: Staphylococci - NVE
MSSA/MSSE
- Nafcillin or Oxacillin 12 g/d IV divided q4-6h x 6 wks (MSSA/MSSE DOC)
- Cefazolin 2 g IV q8h x 6 wks (PCN allergy, but tolerate cephalosporins)
Treatment: Staphylococci - NVE
MRSA/MRSE
Vancomycin 15 mg/kg IV q12h x 6 wks (MRSA/MRSE DOC and for PCN/Ceph allergy)
Daptomycin ≥ 8 mg/kg IV q24h x 6 wks*
Treatment: Staphylococci – Prosthetic Valve or Other Prosthetic Material
MSSA/MSSE
Nafcillin/oxacillin 12 g/d IV divided q4h x ≥ 6 wks + rifampin 300 mg q8h x ≥ 6 wks + gentamicin 1 mg/kg IV q8h x 2 wks (cefazolin may sub for naf/oxa)
Treatment: Staphylococci – Prosthetic Valve or Other Prosthetic Material
MRSA/MRSE
Vancomycin 15 mg/kg IV q12 x ≥ 6 wks + rifampin x ≥ 6 wks + gentamicin 1 mg/kg q8h x 2 wks (also used with severe PCN/Ceph allergy)
Treatment: Enterococci - NVE or PVE/Other Prosthetic Material
Treatment Options: PCN (S) and Gent (S)
1. PCN G 18-30 mU/d divided q4h or via CI x 4-6 wks OR Ampicillin 12 g/d divided q4h x 4-6 wks EITHER, PLUS Gentamicin 1 mg/kg IV/IM q8h x 4-6 wks
- PCN G OR Ampicillin dosed as above x 6 wks
EITHER, PLUS
Ceftriaxone 2 g IV q12h x 6 wks (Recommended for pts w/ CrCl<50 ml/min or who develop CrCl<50ml/min on gent)
Treatment: Enterococci - NVE or PVE/Other Prosthetic Material
Treatment Options: PCN (S) and Gent (R)
Ampicillin 12 g/d divided q4h x 6 wks
FYI: Alternative treatment: Enterococci - NVE or PVE/Other Prosthetic Material
PCN (S), Gent (R), Streptomycin (S)
PCN G 18-30 mU/d divided q4h or via CI x 4-6 wks
OR
Ampicillin 12 g/d divided q4h x 4-6 wks
EITHER, PLUS
Streptomycin 7.5 mg/kg IV/IM q12h x 4-6 wks
Treatment: Enterococci NVE or PVE/Other Prosthetic Material
Unable to tolerate β-Lactams or PCN (R)
Vancomycin 15 mg/kg IV q12 x 6 wks
PLUS
Gentamicin 1 mg/kg IV/IM q8h x 6 wks
Treatment: EnterococciNVE or PVE/Other Prosthetic Material
Treatment Options: PCN (R), Gent (R), and Vanc (R)
- Linezolid 600 mg IV/PO q12h x >6 wks
2. Daptomycin 10-12 mg/kg IV q24h x >6 wks
Treatment: HACEK Organisms - Native or Prosthetic Valve
- Ceftriaxone 2 g IV/IM q24h x 4 wks (may use other 3rd-4th gen. cephalosporin)
FYI: -Ampicillin 2 g IV q4h x 4 wks (only use if organism is susceptible)
-Ciprofloxacin 400 mg IV q12h or 500 mg PO q12h x 4 wks (may use if unable to tolerate option 1 or 2)
Monitoring for efficacy for infective endocarditis
Symptom-based
Resolution of s/sxs over time (VS, CHF MPs, emboli MPs)
Vegetation size usually decreases over months
Microbiologic eradication
Check a set of blood cultures q24h until negative and 2-3d later
Follow-up blood culture 4-8 wks after treatment to verify absence of relapse
Laboratory
Serial ESR (q2-4 wks), CBC, SCr
Serum drug concentration monitoring (vancomycin, AGs)
Repeat echocardiogram at completion of therapy
FYI Monitoring for safety for infective endocarditis
Oxacillin/Nafcillin 12 g/d
Hypersensitivity reactions, baseline and periodic LFTs for hepatic effects and dosing, sx c/w hepatic disturbances, CBC
Ampicillin/penicillin (high-dose)
Hypersensitivity reactions, SCr for dosing, CBC
Ceftriaxone
Hypersensitivity reactions, stool output, CBC
Cefazolin
Hypersensitivity MPs, SCr for dosing, CBC
Rifampin
LFTs, warn of effects on body secretions, sx c/w GI disturbances, CBC
Possible drug interactions
FYI: Prevention of IE (mostly for dental)
Amoxicillin 2 grams PO 30-60 min pre-procedure
Penicillin Allergy:
Clindamycin 600 mg PO 30-60 min pre-procedure
Cephalexin 2 grams PO 30-60 min pre-procedure
Azithromycin or clarithromycin 500 mg 30-60 min pre-procedure
NPO:
Ampicillin 2 grams IV or IM 30-60 min pre-procedure
Cefazolin 1 gram IV or IM 30-60 min pre-procedure
Ceftriaxone 1 gram IV or IM 30-60 min pre-procedure
Clindamycin 600 mg IV 30-60 min pre-procedure
