Infective Endocarditis Flashcards
IE Incidence
- Infective endocarditis
- Uncommon
- Increased incidence in elderly, IDU, and prosthetic heart valves
Risk Factors
- Congenital heart disease + cyanosis
- Rheumatic heart disease following rheumatic fever
- Mitral valve prolapse with regurgitation
- Degenerative valvular lesions; stenosis, regurgitation
- Prosthetic valves
- IDU
IE Pathogenesis
- Endothelial surface of heart damaged
- Platelet and fibrin deposition leading to nonbacterial thrombotic endocarditis formation
- Bacteremia results in colonization of endocardial surface
- Gram “+” more likely to adhere to NBTE from adhesion factors
- After colonization, fibrin, platelets, and bacteria continue to aggregate and a “vegetation” forms
Heart Valves Involved
- Mitral (86%) - most commonly caused by S. viridans when rheumatic heart disease is abnormality
- Aortic (55%) - more acute infections
- Tricuspid (20%) - common site of staph endocarditis in IDU
- Pulmonic (1%)
Acute v.s. Subacute
- Subacute: indolent infections with less invasive organisms (Viridans), common with prior valvular heart disease
- Acute: fulminant infection following infection of a previously normal valve
Non-virulent Organisms
- Low grade fever
- Malaise
- Fatigue
- Weight loss
Virulent Organisms
- High grade fever (common)
- Chills, sweat
- Septic picture
- Embolization complications
IE Clinical Features
- Heart murmur - common and on a scale of 1-6
- Skin lesions
- Other: renal failure, splenomegaly, back pain, abdominal pain, chest pain, etc.
Peripheral Manifestations
- Osler nodes: purple/red subcutaneous papules/nodules that appear on toes and fingers and can be painful and tender
- Roth spots retinal hemorrhages usually caused by immune complex mediated vasculitis
- Janeway lesions: hemorrhagic, painless plaque that develop on palms and soles
- Splinter hemorrhages: thin, linear under nailbeds
- Petechiae: small, erythematous hemorrhagic lesions that aren’t painful or tender
- Finger Clubbing: proliferative change in the soft tissue at the ends of fingers
Labs + Significant Tests
- Blood cultures
- Hematologic: WBC, BUN/SCr
- ESR
- Echocardiogram: TEE more sensitive for detecting vegetation
IE + Major Criteria
- Blood: two blood cultures positive for typical IE organism
- Echo: Positive for IE, myocardial abscess, development of partial dehiscence of a prosthetic valve, new-onset valvular regurgitation
IE + Minor Criteria
- Predisposing heart condition or IDU
- Fever > 38C
- Vascular phenomenon
- Immunological phenomenon
- Positive blood culture results not meeting major criteria
- Echo results consistent with IE but no other major criteria
Vascular phenomenon
- Major arterial emboli
- Septic pulmonary infarcts
- Intracranial hemorrhage
- Conjunctival hemorrhage
- Janeway lesions
Immunological Phenomenon
- Glomerulonephritis
- Osler nodes
- Roth spots
- Rheumatoid factor
Diagnosis
- Definite Endocarditis: microorganism by vegetation culture or cardiac abscess confirmed OR meeting 2 major criteria, 1 major and 3 minor criteria, or 5 minor criteria
- Possible Endocarditis: Findings consistent with IE but falls short of definite
- Rejected: Firm alternative diagnosis or resolution of symptoms in less than 4 days or no pathological evidence at surgery or autopsy
Treatment Guidelines
- Firm diagnosis: presumptive therapy
- Identify organisms: repeat blood cultures
- Bactericidal antibiotics
- Combo therapy needed often
- Duration: 4-6 weeks
- Surgical intervention may be required
Empiric Treatment + Native Valve
- Vanco + Zosyn
* *Empiric = Highly dependent on potential cause of endocarditis**
Empiric + Prosthetic Valve
-Vanco + Gentamicin + Rifampin
Treatment: V. streptococci/S. Bovis + PCN Susceptible
- **PCN G x 4 weeks
- Ceftriaxone x 4 weeks
- PCN G x 2 weeks (when?)
- Ceftriaxone + Gent x 2 weeks
Treatment: V. streptococci/S. Bovis + PCN Intermediate
- (0.12 < MIC < 0.5)
- PCN + Gent x 2 weeks
- Ceftriaxone + Gent x 2 weeks
Treatment: V. streptococci/S. Bovis + PCN Allergy
- Ceftriaxone x 4 weeks
- Vanco x 4 weeks
Treatment: Enertococci or PCN-R V. Strept. + First Line
- PCN G + Gent x 4-6 weeks for Strep
- Amp + Gent x 4-6 weeks - Enterococci
- Amp + Ceftriaxone
Treatment: Enertococci or PCN-R V. Strept. + PCN-R enterococci or PCN allergy
Vanco + Gent x 6 weeks
Treatment: Enertococci or PCN-R V. Strept. + High-level AMG Resistance
-Amp + Ceftriaxone x 6 weeks
Treatment: Staphylococci + Native Valve
Methicillin-susceptible
- **Nafcillin x 6 weeks
- Cefazolin x 6 weeks
- Vanco x 6 weeks (preferred with allergies)
Methicillin-resistant/PCN Allergy
- **Vanco x 6 weeks
- Daptomycin x 6 weeks
Treatment: Staphylococci + Prosthetic Valve
Methicillin-susceptible
- Naficillin AND
- Rifampin x 6 weeks AND
- Gent x 2 weeks
Methicillin-resistant
- Vanco AND
- Rifampin x 6 weeks AND
- Gent x 2 weeks
IE Prophylaxis
- 15-25% from invasive procedures that produce bacteremia
- 10% of IE can be prevented with preprocedure antibiotics
- Consider prophylaxis in those with high-risk conditions and procedures
High-risk Conditions
- Presence of prosthetic heart valve
- History of endocarditis
- Cardiac transplant recipients who develop cardiac valvulopathy
- Congenital heart disease with a high-pressure gradient lesion
High-risk Procedures
- Any procedure manipulating gingival tissue or periapical region of teeth or perforation of the oral mucosa
- Any procedure involving incision in respiratory mucosa
- Procedures of infected skin or musculoskeletal tissue including incision and drainage of an abscess
- Prophylaxis: no longer routinely recommended for GI and GU procedures