Infectious - Inflammatory

Infective endocarditis

PATHO

  • Infection ➔ inflammation of endocardium that affects valves (mitral > aortic > tricuspid > pulmonic)

    • Acute: Staph. aureus (↑in IVDA)

    • Recent prosthetic valve (< 2mo) or infected venous line: Staph. epidermis

    • Older prosthetic valve (> 2mo) or bad teeth: Strep. viridans (subacute)

    • Enterobx from recent GI/UTI infection

    • Strep bovis with hx of colon cancer

    • Gram-NEG H.A.C.E.K. species if cultures don't grow anything or they have really bad teeth/recent tooth infection

    • Candida, Aspergillus if immunosuppressed

  • Bx form little colonies "vegetation" ➔ fibrin encased ➔ embolize "seed" somewhere bad

    • Immune complexes & AB ➔ kidney ➔ glomerulonephritis

    • Septic emboli ➔ stroke

  • Really nasty bx attack "healthy" valve ➔ acute presentation

  • For less nasty bx to cause endocarditis there needs to be a crappier valve

  • Haemophilus species, Aggregatibacter actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, Kingella kingae

    • Part of oral flora and can affect native valves

SSX - Fever with new murmur and predisposition

  • Acute

    • Rapid (days - weeks)

    • Fever (high)

  • Subacute

    • Insidious (weeks - months)

  • IVDA think right side (tricuspid) & RHF sx

  • LHF sx - look for more systems being affected (extracardiac ssx)

  • You get endocarditis FROM JANE

  • Fever

  • Roth spots (retinal hemorrhage with white/pale center)

  • Osler nodes (OW - painful nodules on fingers/palms and toes from immune complex deposits)

  • Murmur

  • Janesway lesions (painless macules on palms and soles)

  • Anemia stuff (immune complexes ➔ splenomegaly/glomerulonephritis ➔ hemolytic anemia/petechiae)

  • Nails (splinter hemorrhage)

  • Emboli (PE from tricuspid vegetation)

DX with DUKE CRITERIA

  • Get three sets of cultures from three different sites before abx

  • 2 Positive cultures (with bx that cause endocarditis) and positive findings on ECHO (2 major criteria) or

  • OR positive findings on echo (1 major) AND 3 minor or

  • 5 minor without positive cultures

Modified Duke Criteria

  • Major:

    • 2 blood cultures with bx known to cause endocarditis:

      • Staph. aureus, epidermis

      • Viridans group Strep

      • H.A.C.E.K.

      • Enterococci

    • Endocardial involvement:

      • Echo shows vegetation, abscess, new dehiscence (sutures failing) of prosthetic valve

      • New regurgitation

  • Minor:

    • Predisposed: IVDA, abnormal/prosthetic valve

    • Fever (100.4)

    • Vascular phenomena (Janeway lesion)

    • Immunlogic phenomena (Osler nodes, roth spots, rheumatoid factor)

    • Cultures that aren't typical of IE or serology shows evidence of infection with bx known to cause

  • Duke's criteria was designed for left sided native valves... the sensitivity isn't as high for right-sided or prosthetic valves

  • Trans-Thoracic echo usually first but Trans-Esophageal is better

TX

  • Critically ill ➔ empiric therapy after 2 (preferably 3) sets of cultures (ideally 30-60 mins apart)

    • Penicillinase resistant β-lactam (oxacillin or nafcillin), vanco if PCN allergy or MRSA

    • AND gram negative coverage (ceftriaxone or gentamicin)

  • Prosthetic valve

    • Vanco + gentamicin + rifampin* or cefepime or carbapenem

  • Prophylaxis abx in pts with hx of endocarditis or prosthetic valves getting I&D or invasive dental procedures

    • Amoxicillin hr before procedure (azithromycin if PCN allergy)

  • Amphotericin B or caspofungin if fungal

  • Surgery if prosthetic valve, new HF or block

  • * Rifampin is good at killing staph that is adherent to prosthetic valves

    • But staph that are susceptible to rifampin have ↑ mutation rate at gene responsible for MOA

      • Starting rifampin early and alone is likely to ➔ resistance

      • Delay rifampin til bx burden ↓ with other abx