Infective Endocarditis Flashcards
How do you diagnose infective endocarditis?
Dukes criteria
Consist of major and minor criteria. To diagnose IE: need 2 major criteria, 1 major and 3 minor criteria or all 5 minor criteria.
Major criteria: - 2positive blood cultures, Positive echocardiogram, new valve regurgitation
Minor Criteria: Predisposing factors (cardiac lesion; IV drug abuse), Fever (>38), Vascular/immunological signs, single positive blood culture
What organism is responsible for 25% of prosthetic valve infective endocarditis?
staph (any bug with staph at the beginning!)
What are the most important parameters for IE diagnosis?
echo (TTE) changes and multiple positive cultures
Whats the condition associated with the highest risk of developing IE?
Prosthetic valve
What is infective endocarditis?
infection of the inner (endocardial) surface of the heart, most commonly involving the cardiac valves.
If untreated what can IE lead to?
Acute HF and death
What are the risk factors for IE?
prosthetic valves Previous endocarditis congenital heart disease IV drug use recent cardiac surgery long term catheters pacemaker body piercings/tattoos haemodyalysis
Describe the pathophysiology of of IE
damage to the endothelium, basement membrane exposed and thrombus forms, platelet activation causes inflammatory reaction, organisms in blood adhere to damaged surface, microorganisms proliferate and promote vegetation, protected from host defences in the clot, the organisms destroy the valve and cause regurgitation
What are the signs and symptoms of IE?
weight loss, fever, lethargy, night sweats, SOB, palpitations, Janeway lesions and oslers nodes, roth spots, splinter haemorrhages, clubbing, murmurs, HF signs (raised JVP, crackles, oedema), embolic vegetations causing abscess formation
what are laneway lesions?
non-tender, flat, erythematous lesions on the palm of the hand.
they are caused by septic emboli depositing bacteria in the dermis
What are oslers nodes?
painful, red raised lesions. caused by immune complex deposition- may also be deposits in joints and kidney–>arthralgia and acute glomerulonephritis
What are roth spots?
retinal haemorrhages with pale/white centre- also seen in diabetes, leukaemia and pernicious anaemia (due to lack of intrinsic factor causing B12 deficiency)
What investigations would you perform if you suspected IE?
Blood cultures before abs started Bloods- anaemia? ESR, leukocytosis Echo to identify valvular dysfunction CXR- to exclude HF ECG Urine dip- haematuria
What % of patients with IE affect a native valve?
75%
What can cause culture negative IE?
abx use, fastidious microorganisms
What abx should you give to IE in native heart valves?
amoxicillin (vancomycin and gentamicin/meropenem if penicillin allergic)
What abc should you give to IE in prosthetic heart valves?
Vancomycin then add gentamicin then add rifampicin
True or false- prophylactic abx are recommended for people undergoing dental procedures
False
In IE what are the 3 indications for surgical treatment?
HF
uncontrolled infection (>7-10days post abx)
Prevention of embolism
what hypersensitivity reaction is involved in IE?
Type 3- immune complex (antibody-antigen)
What are the cardiac complications of IE?
HF
conduction abnormalities
aortic root abscess
MI
What are the possible extra cardiac complications of IE?
embolism
what are some physical signs of infective endocarditis?
clubbing, splinter haemorrhages, changing murmur, splenomegaly, microscopic haematuria
what are the most common causes of splinter haemorrhages?
microtrauma to the nail e.g. due to gardening
vasculitis
Infective endocarditis
