infective endocarditis Flashcards
what is infective endocarditis?
infection of:
- heart valves
- endocardial lined structures eg pacemakers, septal defects or surgical patches
treatment of infective endocarditis
- antibodies/antimicrobials
- surgery to repair and remove infectious material
- then treat the complications which it has caused
name the different types of IE
- native valve IE (mitral or aortic) left sided - most common
- left sided prosthetic valve IE
- right sided IE - tricuspid or pulmonary
- device related IE
what is the most common type of IE
left-sided native valve IE
native valve IE and common organisms
- mitral or aortic
- natural heart valves
- caused by S. verdidans and S. aureas
left sided prosthetic valve IE
- infection of a prosthetic valve
- aortic / mitral
2 groups:
early = <1year of surgery
late = >1 year of surgery
right sided IE
- most common in IV drug users
- effects tricuspid more than pulmonary
device related IE
- infection of cardiac implantable devices
- can occur with/without concurrent valve IE
who is most commonly affected by IE?
- the elderly
- young IV drug users
- the young with congenital heart disease
- anyone with prosthetic heart valves
clinical presenttation
- depends on the site vand bacterial organism
- signs of systemic infection eg fever and sweats
- stroke, pulmonary embolus, bone infection, kidney dysfunction and MI - embolus
- valve dysfunction - heart failure and AF
name the major and minor points of Dukes criteria
major:
- pathogen grown from blood cultures
- evidence of endocarditis on echo or valve regurgitation
minor:
- predisposing factors
- fever
- vascular phenomina
- immune phenomina
- equivival blood cultures
what criteria from the duke’s criteria are for a definite and possible diagnosis?
definite:
- 2 major / 1 major + 3 minor / 5 minor
possible:
- 1 major, 1 minor / 3 minor
contrast the 2 types of echo
transthoracic echo:
- safe
- non-invasive
- no discomfort
- poor quality images - lower sensitivity
transoesophageal echo:
- excellent pictures
- more invase
- generally safe - risk of perforation or aspiration
peripheral stigmata
- classical signs of peripheral embolism from IE
Janeway lesions - painless red macules on palms and soles - embolism lodges in small arteries
oslers nodes - painful red/purple nodules on fingers and toes
splinters and haemorrhages - thin red / brown streaks under finger and toe nails
roth spots - retinal haemorrhage with pale centre
when may someone have a negative culture growth?
if they have had previous antimicrobial therapy
diagnostic tests
- transthoracic echo
- transoesophageal echo
- ECG - secondary complications
treatment
- empiric IV antibiotic until culture comes back
- antibiotics IV - 6 weeks
- treat complications
- surgery
when should you do surgery?
- if infection cannot be cured with antibiotics
- if complications arrive
- remove infected devices
- replace valve after infection cured
- to remove large vegetation before it embolises
who should receive prophylaxis?
only patients at high risk:
Prosthetic Heart Valves
- Previous Infective Endocarditis
- Congenital Heart Disease (CHD)
- Unrepaired cyanotic CHD
- Repaired CHD with residual defects
- Cardiac Transplant with Valvulopathy
takeaway message - F1
- do lots of blood cultures
- always consider IE in sepsis cases
- especially in high risk patients eg those with prosthetic valves
- always consider if INR has shot up (how long it takes blood to clot)
staph epidermidis
most common for prosthetics
staph aureas
IV drug user
frequently affects tricuspid
- symptoms of malaise and night sweats
strep sanguinis
tooth abcess
strep bovis
colorectal carcinoma
coxiella burneli
from animals
why is an elonged PR interval sometimes found
aortic root absess formation
acute IE
- usually IV / healthcare infection / prosthetic device related
- S. aureas / S. pneuomnia
- rapid onset
- severe systemic illness
- major embolism risk
- fever, malaise, night sweats
subacute IE
- dental
- S. virdidans
- slow onset
- low grade fever, fatigue, night sweats
- pre-existing valve disease
- murmur
non-bacterial thrombotic endocarditis
- non-infective
- associated with malignancy
complications of IE
- congestive HF
- septic embolism
- valvar rupture or fistula
- aortic root abcess
what organisms cause negative culture IE?
HACEK organisms
(Haemophilus, Aggregatibacter, Cardiobacterium, Eikenella, Kingella)
contrast right sided and left sided IE
right sided:
- IV drug use
- central venous catheters
- pulm related symptoms, low fever, peripheral oedemia, inv JVP
left sided:
- virdidans strep + S. aureaus
- systemic manifestations - fever, night sweats, malaise
- stroke, renal infarction
before blood cultures come back you administer an empirical antibiotic, what are these for native and prosthetic valve?
native = amoxicillin (+/- gentamycin)
prosthetic = vancomycin + gentamycin + rifampicin
VGR - very good ratification - mnemonic
when blood cultures come back what antibiotics do you give to staff native and prosthetic valve infections? staph
native = flucloxacillin
prosthetic = flucloxacillin, rifampicin and gentamycin
FGR - flipping good radification - mnemonic
when blood cultures come back what antibiotics do you give to staff native and prosthetic valve infections? strep
benzylpenicillin with/without gentamycin
