Define infective endocarditis
Infection of some part of the endocardium, usually valves. Can also be septal defects.
What is the usual etiology of fulminant IE and chronic/subacute IE?
fulminant: S. aureus, S. pyogenes
subacute: Strep virridans
What are predisposing factors for IE?
-structural heart disease
What is the pathogenesis of IE?
Basic: need 1) endothelium damage +thrombosis, 2) bactermia
What are the symptoms of IE?
***The symptoms go on, but they are all non-specific. You have to think of IE in order to make the diagnosis**
What are signs of IE?
signs of emboli
Osler's nodes (painful)
Janeway lesion (not painful)
Roth spots (hemorrhage in the eye)
- splinter hemorrhages
- Osler's nodes (painful)
- Janeway lesion (not painful)
What is the diagnostic approach to IE?
Blood culture is most important!!! (90% of IE will have positive culture, but some hard-to-culture organisms will give a negative result)
Other findings present in some, but not all: anemia, thrombocytopenia, hematuria, proteinuria
Echo (transesophageal more sensitive than transthoracic)
What is the most likely etiology of IE in native valve, IVDU and prosthetic valve IE? What is the empric treatment for each?
- S. aureus or Strep virridans
- Treat with vancomycin and ceftriaxone
- S. aureus, including MRSA
- vancomycin + gentamicin
- vancomycin +gentamicin +rifmapin
**always consult infectious diseases***
Roughly how many prosthetic joint get infected after surgery?
What are risk factors for post-arthroplasty joint infection?
previous infection at the same site*
post-op wound healing complications **
What is the most common etiology of prosthetic joint infection?
Staphylococcus (esp. S, aureus and CNS)
What is the pathogenesis of prosthetic joint infection? Where does the organism come from? How does it evade the immune system?
small infectious dose required
usually skin flora, but can be hemtogenous spread too.
forms a biofilm that protects it from the host immune system and antibiotics
What is the common presentation of acute and "chronic" prosthetic joint infection?
Acute: increase in pain so it's severe and not just when bearing weight, swelling, erythema, warmth, fever
Chronic: pain alone, loosening of the bone/cement interface, sinus tracts
What is the diagnostic approach to prosthetic joint infection?
- there are criteria that include isolating the organism from aspirate on 2 occasions or the presence of a sinus tract, or a collection of other signs
- not terribly helpful. the best is ultrasound.
What is the treatment for prosthetic joint infection?
Take it out. (and treat with appropriate antibiotics)