Infective Endocarditis Flashcards
What is the incidence of infective endocarditis in the UK?
6 per 100,000
What are the symptoms of infective endocarditis?
- Fever + new murmur is infective endocarditis unless proven otherwise
- Septic signs => fever, rigor, night sweats, malaise, weight loss, anaemia,splenomegaly, clubbing
- low grade fever with non specific symptoms is common
What are the signs of infective endocarditis?
- New valve murmur (regurgitation due to valve destruction)
- Embolic event –> PE
- Sepsis of unknown origin
- Immune complex deposition ( haematuria, glomerulonephritis, renal infarct)
-HAND SIGNS:
Janeway lesions, Osler’s nodes, splinter haemorrhages, (roth spots - eyes)
Fever plus:
- prosthetic heart valve
- IVDU
- new ventricular arrhythmia
- new symptoms of CCF
- positive blood culture
- peripheral abscess (renal, splenic, spine) of unknown origin
What are the causes / risk factors of endocarditis?
- organisms in blood AND abnormal cardiac endothelium increased risk of adhereance and growth.
Causes of bacteriaemia:
- poor dental hygeine, recent dental treatment.
- IVDU
- soft tissue infection
- cannula, heart surgery, pacemaker, valve replacement.
- Other : UTI, endoscopy, resp infection, colon cancer, skin disease, fracture.
What are the common organisms that cause infective endocarditis?
- Streptococcus Viridians (35-50%) (from mouth)
- Enterococci (from gut)
- Staphylococcus Aureus / epidermidis (after valve surgery, IVDU, longstanding catheters)
- candida (rare but seen in long indwelling vascular catheters)
- Streptococcus bovis (rare but seen in bowel malignancy)
What invx are done for endocarditis?
1) BLOODS:
- FBC ( raised WCC, anaemia?
- U&Es (renal problems in sepsis)
- LFTs (raised ALP)
- CRP / ESR raised
2) BLOOD CULTURES:
3) URINE DIPSTICK ( proteinuria and haematuria due to immune complex deposition causing damage in renal glomeruli )
4) ECG (MI?, conduction defect? Afib? AV block? –> cause of emboli?)
5) Chest Xray —> HF?, PE?, Abscess?
6) Echo - prosthetic valve endocarditis (-ve echo does not exclude endocarditis)
diagnosis of IE via the DUKE cirtieria requires :
- 2 major + 1 minor
- 1 major + 3 minor
- all 5 minor
What is the major criteria for diagnosis of infective endocarditis?
DUKE CRITERIA:
1) +ve Blood culture (organism in 2 separte cultures or persistenly +ve cultures)
2) +ve serology test for Q fever
3) Endocardium involved (+ve echo - vegetations, abscess, abnormal prosthetic valve)
- new valve regurgitation murmur
diagnosis of IE via the DUKE cirtieria requires :
- 2 major + 1 minor
- 1 major + 3 minor
- all 5 minor
What is the minor criteria for diagnosis of infective endocarditis?
1) Predisposition (caridiac lesions, IVDU)
2) Fever (38’ +)
3) Vascular / immunological signs
4) +ve blood culture
5) +ve echo
What is the treatment for infective endocarditis?
1) Long course 4-6wks Abx.
- emperical (if don’t suspect staph) = Penicillin 1.2g 4 hourly and gentamicin 80mg 12 hourly
- Enterococci (ampicillin or amoxicillin) and gentamicin
- Strep (penicillin and gentamicin)
- Staph (vancomycin and gentamicin)
what factors would increase risk of a staphylococcus endocarditis?
- IVDU
- Intravenous devices (long standing)
- heart surgery
What is the abx of choice for staph endocarditis?
(dont use penicillin)
USE Vancomyic and gentamicin
What is the Abx of choice for strep endocarditis?
penicillin and gentamicin
What is the abx of choice for enterococcal endocarditis?
Ampicillin Or amoxicillin
AND
gentamicin
when should surgery be considered for infective endocarditis?
- Heart failure
- valve obstruction
- repeat emboli
- fungal endocarditis
- myocardial abscess
- unstable infected prosthetic valve
Cultures can be negative for 5-10% of infective endocarditis cases. What is the usual cause?
- prior Abx treatment
Orgnisms that fail to grow in normal blood cultures:
- Coxiella burnetti (cause of Q fever)
- Chlamydia
- Bartonella (cat scratch disease)
- legionella
