Ischaemic Stroke Flashcards
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What is an Ischaemic Stroke?
- Most common type of stroke where oxygen cant get to the brain due to a clot that blocks blood flow
- They’re characterised by rapidly developing signs of focal or global disturbance of cerebral function lasting more than 24 hours or leading to death
- These clots tend to happen in areas of plaque (atherosclerosis)
- Arteries narrow naturally as you age but aren’t a cause outright
Causes of Ischaemic Stroke
- Acute ischaemic strokes are usually caused be thrombotic or embolic occlusion of a cerebral artery
- Can also be haemorrhagic in nature
Pathophysiology of Ischaemic Stroke
- Caused by atherosclerosis which narrows the narrow.
- The plaque breaks off which causes an inflammatory response causing platelets to collect at the site
- This creates a block at the already narrowed artery, stopping blood flow to the brain
- Makes up 90% of all strokes
Pathophysiology of Haemorrhagic Stroke
- Blood vessels or an artery in the brain breaks open, causing a leakage of blood into the brain, stopping the delivery of oxygen and nutrients
- Also called a cerebral haemorrhage
- The build up of blood can also increase the cerebral pressure, causing swelling to the brain, further damaging the brain cells and tissues
Sub-Arachnoid Pathophysiology
- Haemorrhage from a cerebral blood vessel, aneurysm or vascular malformation into the subarachnoid space
- The presentation differs. Typically; sudden onset of severe headache/vomiting and with non-focal neurological signs that may include loss of consciousness and neck stiffness
Signs and Symptoms
- FAST symptoms
- One-sided paralysis/numbness
- Sudden loss/blurred vision (visual disturbances)
- Nausea/vomiting
- Confusion
- Loss of coordination/ balance/change in gait
- Difficulty swallowing (dysphagia)
- Difficulty expressing yourself (dysphasia
- Sudden severe headache
- Dizziness/Fainting/LOC
- Acute onset of neck pain or stiffness
TIA; Definition, Treatment and Non-Conveyance
- Definition - an acute loss of focal cerebral or ocular function with symptoms lasting less than 24 hours
- TIAs mean the pt is at a very high risk of a stoke and need urgent follow ups and investigations
- Even if almost all symptoms have gone, must treat as ongoing stroke
- Follow local guidelines of referral, aspirin administration if not conveyed to hospital
Possible Primary Survey; Ischaemic Stroke
- Obvious one sided paralysis
- Altered GCS
- LOC
- Possible A/B problem
History for Stroke
- What was she doing at the time? was it a sudden onset?
- New headache?
- Any recent falls or head injuries?
- Explore other assc symptoms; nausea, photophobia, visual disturbances, dizziness, confusion, loss of coordination, fainting/LOC
BE FAST Assessment
B - balance, loss of coordination
E - eyes, nystagmus, field of vision loss
F - ask pt to smile, looking for asymmetry
A - pronator drift, test for equal strength
S - ‘you can’t teach an old dog new tricks’
T - note time of onset, 20 mins on scene
What Counts as ‘Speech’ in Speech Assessment
- Naming items
- Jumbled words
- Lack of speech
- Reading
- Writing
PMH/SH/FH/DHx
- Previous TIA’s
- Allergies
- Recent surgeries or head injuries/brain trauma
- Any cardiovascular meds eg anticoags/antiplatelets
- Any FH of strokes
- Alcohol/smoking?
Risk Factors for Ischaemic Stroke
- Smoking
- High cholesterol
- High BP
- Lack of exercise
- Poor diet
- FH
ACHICE in Stroke
Important to put time of onset in ACHICE
Potential Drugs in Ischaemic Stroke
IV Fluids - if less than 90
Glucose 10%
Glucagon if not resolved
Aspirin - only given with suspected diagnosis or in the presence of ECG changes
If FAST-ve Also Asess for…
- Leg strength
- Eyesight
- Sensation
- Coordination
- Gait
- Swallowing
Pathway/JRCALC Guildline for Stroke
- Determine if FAST+ve
- Rule out Hypoglycaemia (treat if needed)
- 4 Lead for AF
NOTE: Treat all presentations with less than 24 hour onset as a time-critical emergency
Oxygen in Strokes
Can give oxygen if the reduced blood flow is so reduced it affects blood oxygen saturation
Analgesia in Strokes
Pt will be in discomfort, especially with a headache. Use paid ladder.
List of Differentials Ischaemic Stroke
- Hemiplegic Migraines
- Bell’s Palsy
- TIA
- Hypoglycaemia
- Migraines
- Tumour
- Posterior Stroke
Tests for Posterior Stroke
- Dysdiadochokinesis Test - Palm to back of hand etc
- Finger to nose
- Heel to shin
- Peripheral vision fields
- Gait
- Rombergs
Signs and Symptoms of Posterioir Stroke
- Difficulty walking, including problems with balance
- Uncoordinated movements of the limbs or trunk
- Tremors
- Vertigo
- Nausea and vomiting
- Intense headache
- Reduced field of vision/visual disturbances
- Speech problems and difficulty swallowing
- Nystagmus
- LOC
