Infective endocarditis Flashcards
What are risk factors for infective endocarditis?
- Acquired valvular heart disease with stenosis or regurgitation
- Hypertrophic cardiomyopathy
- Previous IE
- Use of IV drug
- Recent vascular access (e.g. peripheral venous cannula)
- Recent dental work
- Structural congenital heart disease
- Valve replacement or implantation of a cardiac device
What are the signs and symptoms of infective endocarditis?
- Fever/chills
- Cardiac murmur
- Night sweats, malaise, fatigue anorexia, weight loss, myalgias
- Weakness
- Arthralgias
- Headache
- SOB
- Meningeal signs
- Janeway lesions
- Osler nodes
- Roth spots
- Splinter haemorrhages
What are some differential diagnosis for infective endocarditis?
- Rheumatic fever
- Atrial myxoma
- Libman-Sacks endocarditis
- Non-bacterial thrombotic endocarditis
What bloods do you order for infective endocarditis?
- Blood cultures
- FBC
- CRP
- Serum urea, electrolytes and glucose
- LFTs
What imaging do you do for IE?
- Echocardiography (transthor before oeso unless indicated)
- ECG
What other tests would you do for IE?
urinalysis
How do you take blood cultures is IE?
three sets of blood cultures from different venepuncture sites taken at 30 min interval before initiation of antibiotic therapy
What would the FBC show in IE?
normocytic, normochromic anaemia and 1/3 have leucocytosis with neutrophilia
What is the CRP like in IE?
raised
Why do you do serum urea, electrolytes, glucose and LFTs for IE?
show baseline
What may you see in echo for IE?
valvular, mobile vegetations
What could an ECG show in IE?
- can have conduction abnormalities secondary to IE
1. prolonged PR interval
2. non-specific ST/T wave abnormalities
3. AV block
Why do you do a urinalysis and what may you see for IE?
- can show septic emboli (complication of IE)
1. microscopic haematuria
2. RBC casts
3. WBC casts
4. proteinuria
5. pyuria
What is the 1st line treatment for initial suspected infective endocarditis?
- 1st line: supportive care
- Plus: empirical broad-spectrum antibiotic therapy
- Consider: surgery
What is the first line treatment for acute (native valve and prosthetic valve) confirmed IE?
- 1st line: Correct antibiotics: e.g. beta-lactam/vancomycin/amoxicillin/gentamicin or consult with infectious disease or microbiology
- Consider: surgery
- High dose 6 weeks - IV
- Follow up blood cultures
What is the treatment for ongoing at high risk or IE?
1st line: advice ± antibiotic prophylaxis
What are possible complications from IE?
- Acute heart failure
- Systemic embolization (including stroke)
- AKI
- Anterior mitral valve vegetation >10mm
- Valvular dehiscence, rupture or fistula
- Splenic abscess
- Mycotic aneurysms
What is the prognosis of IE like?
- 50% require surgery
- 20% in hospital mortality
- 15% recurrence at 2 years
What criteria is used for IE?
duke criteria (major and minor)
What bacteria usually causes native valve endocarditis?
- staph.aureus
- vividans strep.
- seen mostly in IV drug
What bacteria usually causes prosthetic valve endocarditis?
- Staph.aureus (MRSA)
What are different type of streptococci than can cause IE?
- S. viridans
- Group D streptococci
- Streptococcus intermedius
- Group A, C and G streptococci
- Group B streptococci
When is S viridans common?
- 50-60% of subacute IE cases
2. part of the normal dental flora, hence associated with dental procedures)
When is Group D streptococci common?
usually subacute and the third most common cause of IE
When is streptoccoccus intermedius common?
- acute and subacute infection
- causes 15% of all cases of IE
When is Group A, C and G streptococci common?
- acute IE is similar to that with S. aureus
2. High mortality (up to 70%).
When is Group B streptococci common?
- acute disease, high mortality often requiring valve replacement
- occurs in pregnancy and the elderly particularly.
What are other rarer causative organisms of IE?
- Enterococci – Nosocomial UTI’s. Gut + urogenital flora
- HACEK organisms (Haemophilus spp.,Aggregatibacter actinomycetemcomitans, Cardiobacterium spp., Eikenella corrodens, Kingella kingae): usually subacute disease and about 5% of all IE.
- Pseudomonas aeruginosa: usually causes acute IE and requires surgery for cure
- Coxiella Burnetii Is very hard to culture.
What is the frequency of the valves affected in IE?
mitral>aortic>tricuspid>pulmonary
What valve is affected for IV drug users?
tricuspid valve is the most commonly affected valve in IV drug users (associated with Pseudomonas, S. aureus, and Candida).
How do you collect blood samples for IE?
blue (aerobic) blood culture bottle should be filled first, then the purple (anaerobic) bottle
Why does the blood need to be collected in this order?
- as the butterfly tubing may contain air
2. air entering the purple bottle will impede the growth of anaerobic organisms
What is the 1st line Ix for IE?
TTE (transthoracic echo) and TEE (transeosophageal echo) - TEE is more invasive and TTE is 1st line unless complication e.g. prosthetic valve
When are antibitocis given in IE?
- Empirical antibiotics (After blood samples taken unless haemodynamically unstable)
- Targeted antibiotics after sensitivity results (2-6 weeks)
What additional treatment is given in IE for prosthetic valves?
prosthetic valve endocarditis, anticoagulation may be required to prevent stroke/PE
What antibiotics are given for staphyloccocus?
flucloxaccilin
What antibiotics are given for staphyloccocus?
flucloxaccilin
What antibtioics are given for MRSA?
Vancomycin/gentamycin
What antibtioics are given for prosthetic valves?
- Staphylococci = Flucloxacillin/Vancomycin + rifampicin + gentamicin
- CONCEPT = MORE AGGRESSIVE ANTIBIOTIC THERAPY IN PROSTHETIC
