Infective Endocarditis Flashcards
What is it?
Which valves does it usually affect?
What does it come after?
Infection of the endocardium of valves
Aortic/mitral
Bacteriaemia
Turbulent flow
Vegetations forms on the valves in endocarditis. What 3 things are these vegetations made from?
Who’s at higher risk?
Formation of vegetations containing bacteria, fibrin and platelets
People with prosthetic or abnormal native valves
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Why is the disease systemic?
It is usually caused by bacteraemia
Sepsis
Multi-system issues - e.g immune complex deposition and emboli
Causes:
Bacterial - the following bac are commonest in who?
- Strep viridian’s
- Staph aureus ****
Other pathogens can cause it!
Non-infective causes:
- How does SLE cause endocarditis?
- How can cancer cause endocarditis?
Main cause is STAPH!!
Valve disease
IVDU
Artificial valves
Fungal - candida, aspergillus
Lupus can cause inflammation of the endocardium. Lupus endocarditis usually causes the surfaces of the heart valve to thicken or develop wart-like growths (lesions). These lesions can become infected, a condition called bacterial endocarditis. A lesion also could break off and travel to the brain to form a blood clot.
According to the researchers, cancer can provoke inflammation of the heart because as tumours grow, they can destroy e.g. the intestinal mucosal barrier and thereby transmit bacteria into the bloodstream – particularly cancer bacteria from the abdominal region, such as colon, liver or biliary cancer. These bacteria are carried around the body by the blood.
Classification:
Infective endocarditis can develop acutely or subacutely.
What does acute IE mean?
What does subacute IE mean?
Develops over days - wks
Subacute bacterial endocarditis
Develops over wks - months
What are the 2 main features?
It is usually caused by sepsis.
- What are the common features of sepsis?
What organ becomes enlarged?
What sign may you see on their hands if they have subacute IE?
Murmur (85%) + fever
Fever
Rigors
Night sweats
Malaise
Splenomegaly
Clubbing***
How does a septic emboli form?
What can septic emboli cause? - 2
Septic emboli originate from a source of infection that becomes complicated with bloodstream infection. A large bacterial inoculum forms on the vulnerable vascular territory, e.g., vegetations on a heart valve or a pacemaker lead or a thrombus in an indwelling vascular catheter or graft.
Infarcts and abscesses - in brain, lung and spleen
Immune complex deposition and vasculitis usually suggest subacute disease:
Vasculitis can lead to haemorrhaging. What signs would you see on or in:
- their skin
- their nails
- the skin on their hands
- the skin on their fingers
What are Roth spots?
What kidney disease can develop?
Petechiae
Splinter haemorrhages
Janeway lesions (JENTLE) - painless palmar lesions Osler nodes (OUCH) - painful infarcts in distal phalanges of fingers and toes
Roth spots - retinal haemorrhages with a pale centre
Immune complex deposition glomerulohnephiritis
Risk factors that increase turbulent flow? - 4
Risk factors that increase pathogen entry and bacteraemia:
- What type of patient would have an increased risk?
- What type of CKD Rx would increase the risk?
Valve disease
Prosthetic valves
Structural disease
Rheumatic heart disease
Congenital Heart disease
HIV infection
IVDU
Haemodialysis
Investigations:
Blood cultures:
- How are they done?
- Within what time should they be done for subacute and acute endocarditis?
3 sets from different sites before starting AB’s
6 hrs
1 hr and 30 mins
Investigations:
Bloods:
What you look for in FBC? - 3
What other special thing could you be looking for that can indicate RHD?
Glomerulonephritis due to endocarditis is present in 50%.
What would be found in urinalysis?
Blood cultures - how should they be taken?
Normocytic anaemia
Raised neutrophils
Raised CRP/ESR
Rheumatic factor
Microhaematuria
(Also do U&E’s)
2/3 sets with a period of (1-6 hrs) between them
If septic - 2 sets within 1 hours and start ABs
Imaging:
What is the main imaging that is used?
What you’d see on CXR?
What happens to the PR interval on ECG?
WHAT CRITERIA IS USED FOR DIAGNOSIS?
Transoesophageal or transthoracic Echo
Transoesophageal more sensitive
CXR - cardiomegaly
ECG - shortened PR interval
Duke’s criteria
Acute management
Which 2 AB’s are given? - start with a and g
For how long?
How long IV?
Antibiotics as soon as blood cultures taken
Benzylpenicillin/amoxicillin + gentamicin
4-6 wks
2 wks IV
Surgery
What is done?
Indications
Debridement
Repair
Replacement
Refractory HF
Persistent sepsis
Emboli
Fungal IE
Prevention
Prophylactic AB’s for high risk dental procedures in patients at risk
