Stroke - Revascularisation Flashcards
What factors determine the extent of the final neurological injury post-stroke?
- Collateral circulation
- Metabolic demands of the tissue
- Time between injury and reperfusion
- Reperfusion injury
What is the ischaemic penumbra?
The area around the affected vascular teritory that has collateral supply and therefore is affected by the hypoperfusion but not to the extent of the central tissue, and is therefore still viable.
Which of the factors mentioned above is the most important in determining stroke prognosis?
Time between event and treatment - time is brain!
Who can we give thrombolysis to?
Pts with ischaemic stroke, within 3.5-4 hours since onset
What initial investigations need to be performed on all pts who present with a stroke?
FBC ESR Clotting U+Es CK LFTs Glucose Lipid profile
ECG
Urgent CT scan
What can we give an ischaemic stroke pt who is not eligible for thrombolysis?
Aspirin (300mg orally or rectally) ASAP
What does aspirin therapy get changed to, and when?
Clopidogrel after 2 weeks of aspirin therapy, unless untolerated or contraindicated (in which case continue lower dose aspirin)
What is very important for us to manage while a pt is in hospital following a stroke?
Blood pressure
What drug do we use for stroke thrombolysis if pt is treated within 3 hours of the event?
Alteplase
What are the NICE recommendations for giving alteplase?
The pt must have had an ischaemic stroke (i.e. haemorrhagic stroke has been ruled out), present within 4 hours of having the event, and there must be specialised services available.
Is there an age limit to using thrombolytic therapy in ischaemic stroke?
No
Is CT or MRI more accurate in detecting chronic haemorrhage?
MRI
Is CT or MRI more accurate in detecting acute haemorrhage?
They are about equal.
Should a pt still have a scan if they have missed the thrombolysis window?
Yes - everyone should get one within 24 hours of presentation.
How should pts who have had thrombolysis be managed following administration of alteplase?
Every patient treated with alteplase should be started on aspirin 300 mg daily after 48 hours, unless contra-indicated. This should be continued for 14 days.
Roughly how many stroke pts actually fulfil the criteria for receiving alteplase? Why is this?
Only up to 10% - the window for effective treatment is so narrow, onset can be very gradual, and may even start during sleep. A certain start time is needed and any uncertainty cannot be accepted.
What is a possible alternative to thrombolysis for ischaemic stroke?
Clot retrieval i.e. thrombectomy
Other than haemorrhagic stroke and not being inside the treatment window, what contraindications are there for thrombolysis?
- Seizure at stroke onset
- Stroke or head injury in last 3 months
- Major surgery or trauma in last 2 weeks
- Previous haemorrhage
- AV malformation or aneurysm
- GI or GU bleed in last 3 weeks
- LP in last week
- Anticoag/INR over 1.7
- Acute pericarditis
What lab results contraindicate the use of thrombolysis?
- Platelets under 100
- INR over 1.7
- Glucose under 2.7 or over 22
- Positive pregnancy test
What is the main possible complication for thrombolysis?
New intracranial haemorrhage
What is the prognosis like following stroke treated with thrombolysis?
If there is good response 24 hours after thrombolysis, then outcomes at 3 months are very good. 30% are normal/near normal neurologically, and 30% only have mild-to-moderate deficits. 50% are completely or near completely independent in ADLs.
