E: Infective Endocarditis Flashcards
What is infective endocarditis
Infection of the endocardium - usually affecting valve leaflets
What is ‘acute’ infective endocarditis
Infective endocarditis in ‘native valves’
What is ‘subacute’ infective endocarditis
Infective endocarditis in damaged/diseased valves
What is the most common causative organism of infective endocarditis
Streptococcus aureus
Why does infective endocarditis occur
Secondary to bacteraemia
What may cause bacteraemia
IVDU
Other infections: UTI
Dental procedures
In-dwelling peripheral venous cannula
What is the most common cause of sub-acute infective endocarditis
Streptococcus viridian’s
In what time does endocarditis of prosthetic valves usually present
within 60d post valve surgery
What is streptococcus viridian’s associated with
Dental procedures
What may cause staphylococcus epidermis infective endocarditis
peripheral venous cannula
What is associated with enterococci infective endocarditis
UTI
GI procedures
What is streptococcus bovis infective endocarditis associated with
Increased risk of later developing colorectal cancer
When may candida or aspergillum fumigates cause infective endocarditis
HIV patients - immunosuppressed
If cultures are negative but other signs are positive for infective endocarditis, what is the likely causative organism
Coxiella Burnetti
What are 4 risk factors for acute IE
Diabetes
Skin breach
Renal failure
Immunosuppression
What valve is most commonly affected in IVDU patients
Tricuspid
How does IE present
Fever and new-onset murmur
What ‘hand-sign’ may indicate IE
Clubbing
What are 4 signs of immune complex deposition in IE
Oslers nodes
Janeway lesions
Roth spots (retinal haemorrhage)
Microscopic haematuria
Explain the pathophysiology of infective endocarditis
Localised infection or contamination causes bacteraemia. Fibrin clots encase the vegetation and cause valve destruction. Bacterial thromboemboli break off and cause subsequent vessel occlusion.
What criteria is used to diagnose infective endocarditis
Duke’s Criteria
What is Duke’s criteria
States that for a definitive diagnosis of infective endocarditis an individual needs:
- 2 major
- 1 major + 3 minor
- 5 minor
What are the 3 ‘major criteria’ involve blood cultures
- Two organisms consistent with IE from two separate blood cultures
- More than 3 positive blood cultures taken more than 12h apart
- Positive culture for coxiella brunette
What are 2 other ‘major criteria’ unrelated to cultures
- Consistent ECHO findings
2. New-onset valvular regurgitation
What are the minor criteria
(BIG-TV)
- Blood Culture not meeting major criteria
- IVDU and other RF
- Glomuerlonephritis
- T > 38
- Vascular phenomenon - janeway lesions, osler nodes
What investigations should be performed in suspected infective endocarditis
- 3 sets of blood cultures performed on 3 separate occasions at least 12h apart
- Transthoracic ECHO
If a negative trans-thoracic ECHO but strong clinical decision what should be done next
transoesophageal ECHO
What does treatment of IE depend on
- prosthetic (or not) valve
- time following surgery
What is treatment for IE in native valve or prosthetic valve >1y following surgery
GAF:
- Gentamicin
- Amoxicillin
- Flucloxacillin
Why is gentamicin given in IE
As it acts synergistically with flucloxacillin against streptococcus aureus
What is treatment for IE with prosthetic valve under 1y
GVR:
Gentamicin
Vancomycin
Rifampicin
What prophylaxis should be given to prevent IE in dental surgery
None - prophylaxis for IE is not recommended
What is a complication of acute IE
Heart Failure
If a patient has undergone a dental procedure and has infective endocarditis, what is the cause
Streptococcus viridian’s
If a patient has developed infective endocarditis after prosthetic valve surgery, what is the likely causative organism
Staphylococcus epidermis
After how long does the spectrum of organisms that can cause infective endocarditis return to normal
2-months
