Infective Endocarditis Flashcards
What are the most common underlying congenital heart diseases predisposing IE?
VSD
PDA
Bicuspid aortic valve
Tetralogy of Fallot
What is the triad for IE?
Endothelial damage
Platelet adhesion
Microbial adherence
What are risk factors for IE?
Skin breeches Immunosuppression Renal failure Prosthetic valves Aortic/mitral valve disease Tricuspid valve in IVDU VSD PDA
How does IE occur?
Structural abnormalities lead to endothelial damage through shear stress forces
Prosthetic material can cause endothelial damage and promote a sterile platelet-fibrin deposition
Bacteraemia can adhere to lesion and invade tissue
What are common organisms in IE?
Streptococcus viridans (alpha haemolytic strep_
Staphylococcus aureus
Stretococcus bovisa
Staph epidermis on prosthetic valves
HACEK organisms
What are signs of IE?
Persistent low-grade fever
New heart murmur - turbulent flow around vegetation
Splenomegaly
Fever, riggers, night sweats, malaise, weight loss
Retinal haemorrhages - Roth’s spots
Splinter haemorrhages - linear haemorrhage streaks in the nail bed
O(uch)sler’s nodes - painful erythematous raised lesions on ends of fingers or toes
Petechiae - skin, mucous membranes, conjunctiva
Janeway lesions - small, painless, erythematous, haemorrhages raised lesions on palms or soles
What are immune complex deposition in IE? Embolic phenomena?
Embolic phenomena - may cause abscesses in various organs
Skin - Janeway lesions
Immune complex deposition
Roth spots
Splinter haemorrhages
What criteria for diagnosing IE?
Modified Duke’s criteria
Positive blood culture - 2 separate cultures or persistently positive blood cultures
Endocardium involved - ECHO findings positive
Minor criteria
Predisposition - cardiac lesion IVDU
Fever > 38
Vascular phenomena - emboli, Janeway lesions
Immunological phenomena - glomerulonephritis, Osler’s nodes
Roth spots
Positive blood culture that does not meet major criteria
2 major
1 major and 3 minor
5 minor
What investigations in IE?
ECHO
Blood cultures
Anaemia
ESR/CRP raised
What are major Duke’s criteria?
Positive blood culture:
Typical organism in 2 separate cultures
or Persistently positive blood cultures
Endocardial involvement
Positive Echo - vegetation, abscess
Abnormal activity around prosthetic valve
What are minor Duke’s criteria?
Predisposition (cardiac lesion, IVDU) Fever > 38 Vascular phenomena Immunological phenomena Positive blood cultures that do not meet major
What is management for IE?
Staphs - native valve = flucloxacillin (vancomycin if MRSA or pen allergic)
Staphs - prosthetic valve: flucloxacillin (vancomycin) + rifampicin + gentamicin for 6 weeks
Streps:
Benzylpenicillin
or benzylpenicillin + gentamicin
Vanc in pen allergy
HACEK - ceftriaxone + gentamicin
What advice for IE?
Importance of maintaining good oral health
Symptoms that may indicate IE
Risks of invasive procedures such as body piercing or tattoos
