endocarditis Flashcards
what is it
endovascular infection of cardiovascular structures including cardiac valves, atrial and ventricular endocardium, large intrathoracic vessels and intracardiac foreign bodies
consequence of what 2 things
- presence of organism in blood stream
- abnormal cardiac endothelium
what can bacteraemia arise
- poor dental hygiene
- IV drug ise
- soft tissue infections
- dental treatment
- cardiac surgery
- pacemakers
does bacteraemia always result in endocarditis
no
what does damaged endocardium promote
platelet and fibrin deposition
what does increase platelet and fibrin deposition allow
organisms to adhere and grow, leading to an infected vegetation
what valves are most commonly involved
aortic and mitral
what valves are usually affected in drug users
right sided
what organisms affect the mouth
- alpha haemolytic viridian’s streptococci
what organisms are caused by vascular catheters and antibiotic use
staph aureus
what organisms affect the gut and perineum
enterococci
what organism affect bowel malignancy
strep. bovis
what organism affect early disease of native valve replacements
- staph aureus
- staph epidermis
what organism affect late occurring endocarditis due to valve replacements
- strep viridian’s
- staph aureus
who is most likely to get soft tissue infections
- diabetics
- IVDUs
- catheters
what organism affects soft tissue infections
staphylococci
what are rare causes of endocarditis
HACEK groups of organism
how bad are the HACEK group
very insidious
what criteria is used
Duke
what is usual cause of culture-negative endocarditis
prior antibiotic therapy
some duet to variety of fastidious organisms that fail to grow
what are examples of organism that cause gram-negative
- coxiella brunetti
- chlamydia
- bartonella
- legionella
symptoms
- malaise (95%)
- clubbing (10%)
- murmurs (90%)
- cardiac failure (50%)
- arthralgia (25%)
- pyrexia (90%)
- osler nodes (15%)
- splinter haemorrhages (10%)
- janeway lesion (5%)
- petechiae (50%)
- Roth spots (5%)
- splenomegaly (40%)
- cerebral emboli (20%)
- ## haematuria (70%)
what symptoms give high clinical suspicion
- new valve lesion/murmur
- embolic events of unknown origin
- sepsis of unknown cause
- haematuria and suspected renal infarction
- fever plus prosthetic material in heart, IV drug user, positive blood culture
what is major criteria for diagnosis
- positive blood culture
- positive serological test for Q fever
- echo
- new valvular regurgitation
what is seen on echo
- an oscillating intracardiac mass on the valve or supporting structures
- an abscess
what is minor criteria for diagnosis
- predisposing heart condition
- predisposing IV drug use
- fever
- intracranial haemorrhage
- laneway lesion
- osler nodes
- Roth spots
- ## positive blood culture but not for criteria
what are the HACEK organisms
- haemophilus
- actinobacillus
- cardiobacgerium
- eikenella corrodens
- kingella kingae
what is very useful for diagnosis
echo
what investigations should be done
- blood culture
- serological test
- FBC
- urea and electrolytes
- liver biochemistry
- inflammatory markers
- urine
- echo
- CXR
- ECG
how is blood culture done
3 sets from different venepuncture sites
when should serological tests be considered
culture negative cases for coxiella, legionella, chlamydia
what is FBC
- haemoglobin
- increase white blood cells
- increased or reduced platelets
what is seen in liver biochemistry
increased serum alkaline phosphatase
what seen in ECG
- PR prolongation
- heart block
what is seen on CXR
- pulmonary oedema in left-sided disease
- pulmonary emboli
- abscess in right side
length of antibiotic treatment
usually prolonged
how long is the antibiotic treatment
4-6 weeks
when do serum levels need to be monitored to prevent toxicity
- gentamicin
- vancomycin
what is used if patient has penicillin allergy
- glycopeptides
- vancomycin
- teicoplanin
what antibiotic is fundamental for therapy
penicillin
treatment when results awaiting and no suspicion of staphylococci
- penicillin
- gentamicin
treatment for suspected staphylococcal endocarditis
recent surgery, acute infection
- vancomycin
- gentamicin
treatment for streptococcal endocarditis (penicillin-sensitive)
- penicillin
- gentamicin
treatment for enterococcal endocarditis
- amoxicillin
- gentamicin
treatment for staphylococcal endocarditis
- vancomycin or flucloxacillin or benzypenicilin plus gentamicin
when should most patients with endocarditis respond
within 48 hours of antibiotic therapy
what is the evidence of resolution
- reduced fever
- reduction in serum markers of infection
- relief of systemic symptoms of infection
if there is no sign of resolution what may be happening
- extension of infection
- hospital-acquired infection
- PE
Is antibiotic prophylactic therapy required
no
what is most common cause
staph aureus
what causes it after dental work
viridians streptococci
when do you always consider endocarditis
new murmur + fever
treatment if caused by staph aureus
flucloxacillin
treatment if caused by MRSA
vancomycin + rifampicin
treatment if caused by viridian’s
benzylpenicillin + gentamicin
treatment if caused by enterococcus
amoxicillin/vancomycin + gentamicin
treatment if caused by staph epidermidis
vancomycin + gentamicin + rifampicin
