Stroke Flashcards
Stroke classification?
“rapidly developing clinical signs of disturbance of cerebral function lasting for more than 24 hours (or leading to death) with no apparent cause other than that of vascular origin” WHO
Transient ischaemic attack (TIA) – symptoms of stroke that resolve within 24 hours
- Ischaemic stroke
- Haemorrhagic stroke
What is ischaemic stroke?
- 70% strokes
- Cerebral thrombosis from atherosclerotic disease
- Distal embolism from cardioembolic disease
What is Haemorrhagic stroke?
- Intracerebral haemorrhage (rupture of small vessel in brain)
- Subarachnoid haemorrhage (rupture of intracranial aneurism in the subarachnoid space)
Symptoms:
F acial weakness: can the person smile? Has their mouth or eye drooped?
A rm (or leg) weakness: Can the person raise both arms (or legs)?
S peech: Can the person speak clearly and can you understand what they say?
T ime: to call 999
A stroke is suspected if ANY of these symptoms are displayed
Also ROSIER (recognition of stroke in emergency room) scale used
Other conditions can present with these symptoms but always investigate to exclude stroke first (MEDICAL EMERGENCY)
Examples:
- Seizures
- Drug toxicity (e.g. overdose)
- Brain tumour
- Migraine
- Spinal cord lesion (e.g. Multiple Sclerosis)
Risk factors
Non-modifiable
- Age
- Risk DOUBLES with every decade over the age of 55
- Gender
- Men at higher risk of stroke (more common in men) BUT
More women die from stroke
- Family hx of stroke, Afro-Caribbean ethnicity
Modifiable
- Hypertension
- Antihypertensives reduce incidence by ~40%
- Atrial fibrillation
- AF implicated in 15% strokes. - Anticoagulation in AF reduces stroke risk by 70%
- Diabetes (2 – 2.5 x more likely to suffer stroke)
- Hyperlipidaemia (statins can reduce stroke incidence)
- Smoking (doubles risk)
Investigations:
- CT (computed tomography) scan – quick
- -> Ischaemic stroke – demarcated hypodense zone (although often difficult to spot)
- -> Haemorrhagic stroke – haemorrhage clearly visible – areas of high attenuation (appear bright)
- MR scan – time-consuming
Useful for investigating TIAs
Also
- BP
- ECG
- FBC & U&Es
- Blood glucose
- Inflammatory markers
Acute treatment:
- Patients should be transferred to a hyper-acute stroke unit as soon as possible
- Investigations performed to confirm diagnosis
- -> NO acute treatment can be administered until CT results back
- Treatments for ischaemic and haemorrhagic stroke very different
Acute treatment – thrombus management
Ischaemic stroke
- Thrombolysis (clot busting drug)
- Alteplase is only licensed treatment. Significantly improves outcomes
- Give within 3 hours of symptom onset
(licensed up to 4.5 hours; under 80s safer). But twice as effective if given before 1.5 hours
- Strict exclusion criteria due to risk of bleeding
Thrombectomy
- Procedure to remove clot (with or without thrombolysis)
- Must be done fairly quickly and in a specialist centre
Window for treatment if much smaller, if you wait too long to thrombolysis
Thrombolysis much safer the younger the patient
Acute treatment - antiplatelet
Ischaemic stroke –>
- Aspirin 300mg
Give as soon as possible (once bleed ruled out)
Give PR or via NG tube if necessary
Continue for (up to) 14 days (two week course compared to MI which is a stat dose)
If patient thrombolysed
- Wait 24hrs before initiating aspirin
- CT scan repeated to ensure no bleed (haemorrhagic transformation)
Acute treatment – haemorrhagic stroke
- Neurosurgical intervention sometimes necessary
- Anticoagulants stopped plus reversed if INR >1.4
- -> Vitamin K
- -> Prothrombin complex concentrate
Reverse to stop bleeding
i.e. aspirin needs to be stopped
Acute treatment – control of blood pressure
- Fluctuating BP (esp high BP) common after acute stroke to try and increase oxygen to the brain
- Ischaemic –> Only manage high BP if hypertensive emergency with complications of hypertension (e.g. MI) or if patient is eligible for thrombolysis
Less than 185/110 mmHg required for thrombolysis
Haemorrhagic
- Treat if greater than 150mmHg systolic (up to 6 hours after symptom onset) or if greater than 220mmHg systolic beyond 6 hours. Aim for 130 - 140mmHg systolic for at least 7 days
Use IV infusion of short acting, rapid onset antihypertensive if one is needed e.g. nicardipine, labetalol, GTN. Note contraindications in NICE guidance. If you need to stop them, the short half life means they can be washed out pretty quickly.
Acute treatment – general measures
Assess ability to swallow (SALT)
- Pharmacist advice on medication, to avoid aspiration pneumonia
- Use Handbook of Drug Administration via Enteral Feeding Tubes (available via Medicines Complete)
Ensure fluid balance monitored and replace fluids as necessary
Monitor temperature (lower with paracetamol if needed)
Tightly control blood glucose, with continuous IV insulin if needed
DVT thromboprophylaxis – heparin used after
- LMWH NOT routinely used (risk of bleed)
- Anti-embolism stockings NOT used
- Intermittent pneumatic compression should be used if patient is immobile
Long-term treatment:
Secondary prevention of further stroke
Secondary prevention of further stroke
- Antiplatelet (or anticoagulant in embolic stroke) – long term (clopidogrel) . NOT in haemorrhagic stroke
- Lower cholesterol (ischaemic) regardless of what the pt’s cholesterol looked like before
- Control hypertension
- Control blood glucose
Treatment of stroke complications:
- Swallowing problems
- Depression
- Dry mouth / sialorrheoa
- Seizures
- Spasticity
