Infective endocarditis Flashcards
Risk factors for infective endocarditis (3 categories)
- Valvular damage (CRAPPI)
- Congenital heart defects
- Rheumatic heart disease
- Age >65
- Past endocarditis
- Prosthetic valve
- Intracardiac devices - Immunosuppression
- HIV/AIDs
- Diabetes
- Malignancy
- Alcoholism - Increased exposure to bacteraemia
- IVDU
- Haemodialysis
- Dental surgery
Most common cause of short incubation (less than 6 weeks)
Staphylococcus aureus
Most common cause of long incubation (more than 6 weeks), community acquired IE
Streptococci
Causes of culture-positive IE (4)
- Staph aureus
- Viridans Alpha-haemolytic streptococci
- Enterococcus
- Pseudomonas
Causes of culture-negative IE
- Prior antibiotic administration
- Fastidious organisms
- Aspergillus
- Brucella
- Coxiella burnetii
- Chlamydia
- HACEK group
HACEK organisms
Fastidious gram negative bacteria. Account for 5-10% cases in native valves. Normal oral-pharyngeal flora.
Haemophilus Aggregatibacter Cardiobacterium Eikenella corrodens Kingella
Most common side of heart affected, and the major risk factor for IE of the OTHER side
- Most common side is left
- Right seen in IVDU
Pathophysiology of IE
Platelets and fibrin deposit on damaged valves, causing bacteria to adhere. Failure of immune cells to reach the valves due to indirect blood supply results in colonisation of the valve.
Clinical presentation of IE
FROM JANE
- Fever/fatigue/malaise/weight loss
- Roth’s spots
- Osler’s nodes
- Murmur (new or changing)
- Janeway lesions
- Anaemia
- Nail haemorrhage
- Emboli
May also have cough, glomerulonephritis and splenomegaly
Management of IE
Fulminant IE
-Start IV vanc and ceftriaxone, high dose for 2-6 weeks
Subacute IE
- Delay treatment until microorganism is identified
- For streptococci - penicillin or ceftriaxone +/- aminoglycoside
Complications of IE (4)
- Heart failure
- Abscess formation
- Septic emboli
- Prosthetic valve dehiscence
Percentage in-hospital mortality
18%
