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Infective Endocarditis

From Mediwikis

Cardiac valves(most commonly Aortic/Mitral), endocardium, prosthetic devices become infected via endovascular spread of pathogens, onto abnormal or damaged cardiac epithelium, forming a vegetation.

Spread

Bacteraemia, caused by medical, surgical or dental work (though prophylactic antibiotic therapy is not indicated), or following inoculation i.e. in IV drug use, or following systemic infection.

Pathogens

  • Staph. aureus
  • Strep. viridans

Signs & Symptoms

FROM JANE:

  • Fever
  • Roth's spots
  • Osler's nodes
  • Murmur
  • Janeway lesions
  • Anaemia
  • Nail haemorrhage (splinter haemorrhages)
  • Emboli

Investigations

  • Blood Culture
  • Urinalysis- Haematuria
  • Echocardiography
  • FBC- Normochromic, normocytic anaemia, neutrophilia
  • U&E, LFT
  • ECG- prolonged PR
  • CXR- Cardiomegaly

Duke Criteria

Two major, or one major and three minor, or five minor for definite diagnosis. One major and one minor, or three minor makes it "possible".

Major:

  • Positive blood culture- typical microorganism without obvious primary focus
  • Positive blood culture from 3 samples, or samples 12h apart
  • Positive Q fever test
  • Echocardiac evidence showing vegetations
  • New valvular regurgitation

Minor:

  • Risk factor for endocarditis- congenital abnormalities, IV drug use
  • Fever
  • Embolic pnenomena- arterial emboli, intracranial haemorrhage, Janeway lesions
  • Immunologic pnenomena- glomerulonephritis, Osler's nodes
  • Microbiological evidence- atypical culture, or serological proof of typical organism

Management

Consult microbiology. Prolonged course of antibiotics (4–6 weeks)

  • Empirical: Benzylpenicillin & Gentamycin ± Flucloxacillin
  • Surgery may be required