infective endocarditis

Question 1

how may a patient develop a septic shock?

Answer 1

• where there is bacteria in the blood stream

- life-threatening

Question 2

what questions should you ask about positive cultures?

Answer 2

1. what is the habitat of this organism
2. what diseases is this organism associated with?
3. what is the optimum antimicrobial management required?

Question 3

what kinds of organisms are found on the skin from cardiac implantable electronic devices?

Answer 3

• staphylococcus aureus
• staphylococcus epidermidis
• corynebacterium sp.
• propionibacterium acnes

Question 4

what are the risk factors for ICED infections?

Answer 4

• 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

Question 5

what is generator pocket infection?

Answer 5

• localised cellulitis
• pain
• swelling
• discharge
• wound breakdown

Question 6

when should blood cultures be taken?

Answer 6

• prior to starting antimicrobial therapy
• wait 1 hour before giving antibiotics if they have septic shock, wait longer if not
• take good quality samples

Question 7

what is endocarditis?

Answer 7

• infectoin of endothelium of heart valves
• left threatnenin - often diagnosed late
• up to 25% mortality
• may be acute or subacute

Question 8

what is the epidemiology of endocarditis?

Answer 8

• 1/1000 hospital admissions
• increasing mean age >50 years
• hospital-aquired cases increasng, due to staph aureus

Question 9

what are the predisposing factors of infective endocarditis?

Answer 9

• heart valve abnoramlity
• calcificaiton in elderly
• CongenitalHD
• post rheumatic fever
• prosthertic heart valve
• IV drug users
• intravascular lines

Question 10

what is the pathogenesis of endocarditis?

Answer 10

• 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)

Question 11

what are the main organisms cauing endocarditis native valve?

Answer 11

• staph aureus
• viridnas group streptococci
• enterococcus sp
• staph epidermis

Question 12

what are the unusual organisms endocarditis?

Answer 12

• 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

Question 13

when would you look up DUKES criteria?

Answer 13

• if you think there is endocarditits,

Question 14

when would a blood cultures be positive for IE?

Answer 14

• 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

Question 15

are hacet group difficult to grow?

Answer 15

yes

Question 16

how many blood cultures should be taken?

Answer 16

• 3

Question 17

how can staphylococcus aureus be distinguished from coagulase-negaitve staph?

Answer 17

• coagulase test

Question 18

what are staph?

Answer 18

• gram positive cocci in clusters = staph

Question 19

what is staohylococcus epidermis in blood cultures?

Answer 19

• most common coagulase-negtive stapylococcus
• often a skin contaminant, BUT can infect prosthetic material eg intravascular line infections, prosthetic heart valves/joints
• take more than one set of blood cultures to cnfirm significance
• other skin contaminants: corynebacterium sp

Question 20

what are the presenting symtpms of acute endocarditits (compares to SBE)?

Answer 20

• presents as overwhelimng spsis and cardiac fialure

- usually due to aggressive (virulneT) organisms such as staphylococcus aureus

Question 21

what is the subacute presentations of acute endocarditis?

Answer 21

• fever
• malaise
• weight loss
• tiredness
• breathessness

Question 22

what are the subacute presentations of acute endocarditits?

Answer 22

• fever
• new of chnaging heart murmur
• finger clubbing
• splinter haemorrhages
• spineomgeay
• roth spots, janeway lesions, osler . nodes
• microscopic haematuria

Question 23

how are streoptococci named?

Answer 23

• ocygen requirement
• lancefield groups
• haemolysis on agar
• biocemical tests

Question 24

where do viridans group streptococci live?

Answer 24

• mouth

Question 25

what colour ar eviridans group stroptoccoi?

Answer 25

• green

Question 26

what are the names of the alpha haemolytic strep?

Answer 26

• strep mitis
• strep sanguinis
• strep mutans
• strep slivarius

Question 27

what shows positive imagine for IE?

Answer 27

• vegetation, abcess, psuedoaneuryms, intracardia fistula, valve perforation, new partial dehiscence of a valve prosthesis

Question 28

what is prosthetic valve endocarditits?

Answer 28

• early (within 60 dyas) and late presentation
• early - usulaly infected at the time of valve insertion and usually due to stephulococcus epidermis or staphylococcus aureus
• late = up to mnay years after valave insetion - due to co-incidental bacteraemia, wide range of possible organisms

Question 29

what is endocarditis in PWID?

Answer 29

• right sided endocarditits (tricuspid> mitral>aortic)
• usually staph aureus
• suspect in staphylococcus aureus plus septic pulmonary emboli

Question 30

what is the empirical treatment of endocarditis?

Answer 30

• native valve endocarditis = amoxicillin and gentamicin IV
• prosthetic valve endocarditits = vancomycin and gentamyocin IV, add in day 3 to 5 (delayed) rifampicin PO, often valve replacemnet is required
• drug user endocarditis (MSSA) = flucolacillin IV

Question 31

what is specific endocarditits treatment?

Answer 31

• stephylococcus aureus (not MSSA) = flucloxacillin IV
• MRSA treat as per prosthetic valve - viridans streoptocicci = benzylpenicllin IV and gentamicin IV
• enterococcus sp = amoxicillin / vancomycin and gentamicin IV
• stephylococcus epidermis = vancomycin and gentamicin IV and rifampicin PO

Question 32

how is therpy monitored?

Answer 32

• IV antibiotics usually given 4-6 weeks
• monitor cardic fucntion, temperature and serum C-reactive protein )CPR_
• if fialing on antibiotic therpy, consider referral for surgery early

Question 33

what is myocarditis?

Answer 33

• most common in young people
• symptoms - fever, chest pain, SOB, palpitations
  signs = arrhythmia, cardiac failure

Question 34

what is myocarditis caused by?

Answer 34

• enteroVIRUSES - COXSACKIE A AND B, ENCHO VIRUS,

Question 35

how is myocarditis diagnosed?

Answer 35

• viral PCR

Question 36

what is pericarditis?

Answer 36

• occurs with myocardiits
• chest pain
• viral aetiology mainly, supportive treatment
• bacteria less common
• eg post cardiothoracic surgery, rarely secondary spread from endocarditits or pneumonia treatment, antibiotics and drainage