ENDOCARDITIS

 

Etiology:

  • S. viridans, enterococci (strep group D, GU origin) and S. bovis ( GI origin - bacteria or CA) - account for over 50%.  They commonly cause SBE.  Affect native valve (except R valves).
     
  • S. aureus (affects normal valves on the R or L side; seen commonly in IVDU or indwelling IV) and S. epidermis (most common in prosthetic valve) -20%. They commonly cause ABE.
     
  • Other causes are G (-), fungi,* and HACEK (Haemophillus, Actinobacilli, Cardiobacterium, Eikenella, Kingella), Libman-Sacks (in pts with SLE)

 

S & S:

  • Either  of  the organisms can cause Acute or Subacute Endocarditis (ABE or SBE ). The distinction is based on the duration of prodrome.
     
  • The ABE pt usually has 1 - 7 days of prodrome such as high fever and possible vascular/collagen manifestations.
     
  • The SBE pt has 1 - 2 wks of wt loss, low grade fevers, night sweats, vascular/collagen/immune manifestations such as arthritis, Osler nodes, Janeway lesions, Roth spots and possible embolic lesions to brain/lung/kidney.  These S & S can be present also in ABE but given short duration of onset are less frequent than in SBE.
     
  • Fever is present in 90% of cases.
     
  • Murmur almost always present in SBE and eventually develops in ABE. Not uncommonly though, the murmurs are present in previous history and that is what predisposes the pt to develop endocarditis.
     
  • Roth spots on the retina:  flame-shaped hemorrhages with pale center.
     
  • Osler nodules on pulp of digits:  Represent vasculitis. Painful.
     
  • Janeway lesions: painless hemorrhagic macules on palm/soles.
     
  • Subungual splinter hemorrhages.
     
  • Arthritis.
     
  • Hepato / Splenomegaly in 30-60%.
     
  • Petechiae in 50%.  Can be seen on skin or mucosa.
     
  • Pleural/pericardial rub.
     
  • Clubbing.
     
  • Embolic lesions to brain (confusion), to kidney (hematuria), to lungs (hemoptysis), spleen (L  flank pain), coronaries (MI).

DX:

  • In 1994 new Duke's criteria for dx were developed and c/o: (+)ve bcx, fever, predisposing factors, murmur and vegetation on Echo (TEE is very sensitive).  If pt has prosthetic valve, sensitivity decreases.
     
  • 3-6 blood cultures in 24hrs. When time is a factor 3 bcx 1 hr apart from different sites is standard of care.
     
  • Increase, decrease or normal WBC.  Shift may be present.
     
  • Hematuria, proteinuria.
     
  • Increase ESR.
     
  • Echo.  May be indicated in ED to estimate valve pathology and its potential hemodynamic compromise
     
  • Cxray  may show prosthetic valve, cavitations 2ry to septic emboli.
     
  • Obtain urine culture.  Perform rectal exam (guaiac positive stools may suggest GI origin or vasculitis).

Medical Treatment:

  • In  this compilation  we will deal with the "empiric treatment awaiting cultures" scenario.
    1. Native Valve:  Pen G 20 million U qd + Nafcillin  or Oxacillin 2g IV q4 + Genta 1.5mg/kq8hrs.  If Pen allergy, Vanco 15mg/kg q12hrs + Genta 1.5 mg/kg  q8hrs.
       
    2. Prosthetic Valve: Vanco 15mg/kg q12hrs + Genta 1.5mg/kg + Rifampin 600mg PO qd.  Obtain surgical consult early.
       
  • Some will recommend  withholding  treatment until culture results are available if pt is not
     
  • ill appearing, not hemodynamically  unstable, and did not develop complications (e.g. emboli).

Surgical Treatment:

  • Hemodynamic compromise 2ry to valve obstruction/distraction.
     
  • Fungal infection (Candida).
     
  • Embolic events with documented valvular vegetation.

Indication for Prophylaxis Against Endocarditis:

  • Any procedure that will cause bleeding and bacteremia and pt has congenital or acquired valve disease:
     
  • IHSS, MVP with regurgitation, pulmonary stenosis, prosthetic valve, RHD with valvular disease, intravascular device.
     
  • Dental infection with gingival bleed.
     
  • GI procedures (colonoscopy  or UGI endoscopy with biopsy or sclerotherapy of varices).
     
  • GU procedure, e.g. cytoscopy  or  foley insertion in presence of  infection.
     
  • Rigid bronchoscopy (not ET intubation)
     
  • Prophylaxis not needed after CABG, PPM, MVP without murmur, RHD without valve disease, ETT, flex bronchoscopy, TEE, simple foley cath placement.  For more complete list of procedures see specialized textbooks.

Prophylactic Antibiotic Regimen:

  • If  this is a minor procedure/trauma:
     
    • Amoxicillin 2g PO 1hr before the procedure.  If PCN allergy: clindamycin 600mg, Cephalexin 2g PO (and other 1st generation, but depending on type of allergy), or azithromycin (or clarithromycin) 500mg PO, all 1 hour before the procedure.
       
  • If major procedure/trauma:
     
    • Ampicillin 2g IV/IM 30 minutes before the procedure.  In the PCN allergic patient,   clindamycin 600mg IV or Cefazolin 1g IV/IM (depending on type of allergy) 30 minutes prior to the procedure.
       
  • For GI/GU procedures:  Ampicillin 2g IV/IM + Gentamicin 1.5mg/kg IV/IM is given 30 minutes before the procedure.  In PCN allergy, Vanco 1g IV infused slowly over 1 hour prior to procedure + Gentamicin 1.5mg/kg IV/IM 30 minutes before the procedure .