Stroke - ischaemic 2 Flashcards
Why does the secondary treatment of stroke differ between cardioembolic and atheroembolic strokes ?
- As cardioembolic is caused by Fibrin dependent “red thrombus”
- And atheroembolic is caused by Platelet dependent “white thrombus”
What are the risks/causes for developing cardioembolic strokes ?
- Having AF
- External cardioversion carries a risk of emboli
- Prosthetic valves carry a risk of emboli
- Having a MI recently
- Heart defects e.g. patent foramen ovalae, ASD, VSD
- Having had cardiac surgery e.g. bypass graft
- Valve vegetations due to infection e.g. infective endocarditis carry risk of emboli
These can all cause emboli which travel up to the brain and cause an infarction ==> cardioembolic stroke
What is the most common of the 2 main types of ischaemic strokes ?
Atheroembolic
What initial assessment tool should be used in A&E to assist with more rapid diagnosis of stroke ?
- ROSIER scale
- If score >0 then likely to have had/having a stroke
- Score ranges from -2 to 5
- https://dundeemedstudentnotes.files.wordpress.com/2012/03/rosier.pdf
What is the initial first investigation done to diagnosis and differentiate between ischaemic and haemorrhagic strokes ?
- CT
- If they present after 1 week then do an MRI as CT is no longer any good
What are the risk factors for people developing atheroembolic strokes ?
- High cholestrol and BP
- Smoking
- Diabetes and obesity
- Physcial inactivity
What are the other initial investigations done for someone with a stroke ?
- ABC - protect the airway and prevent aspiration
- Do pulse, BP and 24hr ECG - purpose of ECG is to look for AF
- Blood glucose - to rule out hypoglycaemia
- Cardiac enzymes
- Electolytes, FBC, serum urea and creatinine
- Check PT and PTT times to rule out a bleeding disorder (coagulopathy) If patient has no history of anticoagulant use, or of coagulopathy or a condition that may lead to it, then thrombolysis does not need to be delayed until the test results are available
What are the other investigations done for someone with a stroke ?
- CXR - may show enlarged L atrium
- Echocardiogram - may show mural thrombosis seen in AF ,or show signs they’ve had an MI or may show valvular lesions in infection endocarditis or rhematic heart disease
- Carotid artery doppler ultrasound +/- CT/MRI angiography
- Check for conditions which might cause clots e.g. vasculitis, thrombophilia, antiphospholipid syndrome (only if suggested)
What is the investigations done to differentiate between the cause of an ischaemic stroke being likely to be atheroembolic or cardioembolic ?
Assessing to see if cardioembolic likely:
- Echo - may show signs of post-MI, AF, infective endocarditis, rheumatic heart disease
- ECG 24hr - to look for AF
- CXR - enlarged atrium
Assessing to see if atheroembolic likely:
- Carotid doppler ultrasound - if stenosis > or equal to 70% then atheroembolic likely
Describe small vessel disease
Its an umbrella term covering a variety of abnormalities realting to small blood vessels in the brain
Often seen lacunar infarcts (type of small stroke), white matter hyperdensities and cerebral microbleeds
Many problems have been associated with cerebral SVD including:
- congnitive impairment - When problems with thinking skills are associated with SVD, this can be called “vascular cognitive impairment.”
- Problems with walking and balance
- Strokes - white matter hyperintensities are associated with a more than two-fold increase in the risk of stroke.
- Depression
- Vascular dementia
Causes of small vessel disease
- Arteriosclerosis
- Microatheroma of the ostium,
- Embolism (athero and cardioembolism)
- Changes in hemorrheology
Where should stroke patients be admitted to in hospital ?
Stroke care unit
What is the initial treatment of ischaemic stroke after using brain imaging to differentiate ischaemic from haemorrhagic stroke if they are seen within 4.5hrs of onset of symptoms?
1st = Thrombolyiss with aletepase (intravenous rt-PA)
Adjunct = aspirin given after 24hrs if recieved thromoblysis and continue for 2weeks following stroke
Adjunct = endovascular intervention (thrombectomy with stent retriever) in selected patients
Supportive care should be provided throughout treatment e.g. giving O2 or ventilation
Swallow assessment including nutrition and hydration assessment within 4hrs of presentation
VTE prophylaxis and early mobilisation
What are the indications for use of thrombectomy ?
selected patients with acute ischaemic stroke who have confirmed large vessel occlusion:
have received intravenous r-tPA within 4.5 hours of onset;
have causative occlusion of the internal carotid artery or proximal middle cerebral artery - the main indication for its use is someone with a large proximal vessel occlusion of the anterior circulation (internal carotids and middle cerebral, think the anterior cerebral is a bit small or something)
aged ≥18 years;
can begin endovascular therapy within 6 hours of symptom onset. (think this means as long as it can be done within 6hrs)
What is the initial management of ischaemic stroke when the patient is seen after 4.5hrs of symptom onset?
1st - aspirin continue for 2wks following stroke
- Supportive care
- Swallowing assessment including nutrition and hydration assessment within 4hrs of presentation
VTE prophylaxis + early mobilisation
