Infective Endocarditis Flashcards
(35 cards)
What is the definition of endocarditis?
Inflammation of the endocardium which is the inner layer of the heart
Usually involves the valves and characterised by vegetations
What are vegetations made up of?
Platelets, fibrin and microorganisms
Describe the process of endocarditis
Pathogens gain access to the blood stream - there is adherence to valve surface - persistence of bacteria - proliferation - dissemination
What can vegetations be seen on?
Echo - appear as grey masses
How is infective endocarditis variable?
Highly variable - acute, fulminant and subacute/ chronic disease
How is infective endocarditis a systemic disease?
Embolic strokes, pulmonary embolism, myocardial infarction, infraction of kidney, spleen, mesenteric, skin and has immune response
What are predisposing conditions for infective endocarditis?
Prosthetic valves, cardiac devices, intravenous drug users, congenital heart disease, rheumatic valve disease, mitral valve prolapse, immunosuppression and prolonged admission to ITU
What are some signs of endocarditis in other organs?
Embolic stroke, roth spots, mitral valve vegetation, pacer lead with vegetation, aortic valve leaflet with perforation, septic pulmonary emboli, splenic infarcts and peripheral finger infarcts
What are the signs and symptoms of infective endocarditis?
Fever - chills/rigors, poor appetite and weight loss
Heart murmurs
Less frequent - myalgia, back pain and confusion
Embolic complications
What are some vascular and immunological phenomena?
Osler’s Nodes that are red and painful on fingers and toes
Retinal haemorrhages
Splinter haemorrhages
What are some non-specific signs of infection - lab?
Elevated C-reactive protein, erythrocyte sedimentation, leucocytosis, anaemia and microscopic haematuria
What is needed for diagnosis of endocarditis?
Lab signs of infection and blood cultures (at least 3 sets that are 30 mins apart)
Blood cultures are essential prior to antibiotic therapy is commenced.
What are some common microbiology found in the blood cultures?
Staph. aureus, streptococci, enterococci, coagulase negative strep. and HACEK group
What are some microorganisms that cause a negative IE on blood culture?
Brucella spp, coxiella burnetti, bartonella spp, and can be non-infective so systemic lupus or marantic endocarditis
What is the imaging used to diagnose endocarditis?
Transthoracic echo as soon as IE is suspected
Transoesophageal echo
CT/MRI for detection of embolic events
Positron emission tomography - PET shows areas of inflammation
What is the diagnostic criteria for definite IE?
2 major criteria
1 major and 3 minor criteria
5 minor criteria
What is the diagnostic criteria for possible and rejected IE?
Possible - 1 major and 1 minor
3 minor criteria
Rejected IE - alternative diagnosis
What is included in major criteria for IE?
Blood culture positive for typical microorganisms
Echo showing valvular vegetation
What is included in minor criteria for IE?
Predisposing cardiac lesion, IDU, temp., embolic phenomena, immunologic phenomena and positive blood culture not meeting above criteria
What decided the patients prognosis?
Patient characteristics - older age, comorbidities and diabetes
Infecting microorganism
Presence of cardiac/ non cardiac complications
Echo findings
Who is included in endocarditis team?
Cardiologist, microbiologist, cardiac surgeon and nurse specialist
What is the antibiotic treatment if oral strep. or strep. bovis group?
Penicillin G
or amoxicillin or ceftriaxone
What is the antibiotic treatment if staph spp. native valves?
Flucloxacillin
What is the antibiotic therapy if prosthetic valves?
Add rifampicin and gentamicin for at least 6 weeks of therapy
