infective endocarditis Flashcards
how may a patient develop a septic shock?
- where there is bacteria in the blood stream
- life-threatening
what questions should you ask about positive cultures?
- what is the habitat of this organism
- what diseases is this organism associated with?
- what is the optimum antimicrobial management required?
what kinds of organisms are found on the skin from cardiac implantable electronic devices?
- staphylococcus aureus
- staphylococcus epidermidis
- corynebacterium sp.
- propionibacterium acnes
what are the risk factors for ICED infections?
- no pre preocedure prophylaxis
- complexity of procedure
- temporary paper use
- type of device
number of revisions/ reinterventions - fever within 24 hours
- heart failure, renal failure
- haematoma post procedure
what is generator pocket infection?
- localised cellulitis
- pain
- swelling
- discharge
- wound breakdown
when should blood cultures be taken?
- prior to starting antimicrobial therapy
- wait 1 hour before giving antibiotics if they have septic shock, wait longer if not
- take good quality samples
what is endocarditis?
- infectoin of endothelium of heart valves
- left threatnenin - often diagnosed late
- up to 25% mortality
- may be acute or subacute
what is the epidemiology of endocarditis?
- 1/1000 hospital admissions
- increasing mean age >50 years
- hospital-aquired cases increasng, due to staph aureus
what are the predisposing factors of infective endocarditis?
- heart valve abnoramlity
- calcificaiton in elderly
- CongenitalHD
- post rheumatic fever
- prosthertic heart valve
- IV drug users
- intravascular lines
what is the pathogenesis of endocarditis?
- heart valve damaged
- turbulent blood flow over roughened endothelium
- patelets/ fibrin deposited
- bacteraemia (may be transient) eg from dental treatment organisms settle in fibrin/platelet thrombi becoming a microbial vegetation
- infected vegetations are fribale and break off, becoming lodged in the next capillary bed they encounter causing absesses or haemorrhage - may be fatal
- usual left side of heart affected (mitral and aortic valve)
what are the main organisms cauing endocarditis native valve?
- staph aureus
- viridnas group streptococci
- enterococcus sp
- staph epidermis
what are the unusual organisms endocarditis?
- atypical organisms = bartonella, coxiella burnetii (Q-fever), chlamydia, legionella, mycoplasma, brucella
- gram negatives = HACEK organisms = haemophilus spp, aggregatibacter soo, cardiobacterium, eikenella sp, kingella sp
- NON HACKET gram negatives = fungi
when would you look up DUKES criteria?
- if you think there is endocarditits,
when would a blood cultures be positive for IE?
- detection of endocarditits-specific pathogens in 2 independant blood cultures: viridans streptococci, streptococcus gallolyticus (bovis), HACEK group, staohylococcus aureus or community -aquired enterococci without evidence of primary focus
- or microorganisms compatibla with an IC in peristsanely positive blood cultures: at least 2 positive blood cultures from blood withdrawals at least 12 hours apart or each or 3 of a pluarity of > 4 separate blood cultures
- or a single positive blood ulute with coxiella burnetti or phase I IgG
are hacet group difficult to grow?
yes