lecture 9: stroke Flashcards
what is the #1 potentially modifiable risk factor of stroke
HTN!
list potentially modifiable risk factors of stroke
- HTN
- heart disease - atherosclerosis
- DM
- tobacco use
- abdominal obesity
- carotid stenosis
- atrial fibrillation
- dyslipidemia
- excessive alc
- physical inactivity
- hypercoagulability
- illegal drugs
non-modifiable risk factors of stroke
- increasing age
- gender
- hereditary
- ethnicity
- low birth wt
- previous stroke or TIA
- arteriovenous malformation
- congenital heart disease
- valve disorders/endocarditis
- blood disorders (increased RBCs; sickle cell anemia)
if an individual has a artificial heart valve what will they be on
anticoagulants!
why is it important to know where the clot or rupture is for a stroke
will tell us what part of the brain is effective and likely s/s
what does our frontal lobe do
- problem solving
- emotional traits
- reasoning (judgement)
- speaking
- voluntary motor activity
what does our parietal lobe
- knowing right from left
- sensation
- reading
- body orientation
what does our occipital lobe do
vision and colour perception
what does the temporal lobe do
- understanding language
- behaviour
- memory
- hearing
what does the brain stem do
- breathing
- body temp
- digestion
- alertness/sleep
- swallowing
what does the cerebellum do
- balance
- coordination and control of voluntary movement
- fine muscle control
why is adequate cerebral blood flow important
Need constant supply so your brain is able to function
It is very small compared to rest of your body - but has HUGE requirement so this is crucial
Blood flow to the brain is completely interrupted, metabolism is interrupted in 30 sec, cell death can be within 5 minutes
describe autoregulation of cerebral blood flow
automatic alteration in diameter of cerebral blood vessels during changes in BP
if perfusion is decreased there is autoregulation to help out
MAP: mean arterial pressure
We don’t need to know that calculation or stats
Normal map is 70-100
when does autoregulation fail
MAP < 50 mm Hg
MAP > 150 mmHg
When someone has a very low MAP, it can fall below 50 and really high bp is above 150
Hypertensive/hypotensive your brains mechanisms are impaired
Normal pressure - there is vasodilation to improve
why is normal intracranial pressure so important
Brain is enclosed - no soft tissue so accumulation puts pressure on your brain unlike if you got a bruise on your arm
Increased pressure: bleed, any swelling (concussion), brain tumour
Normal: 5-15 for intracranial pressure
- If over 25 this is often fatal - not much room for movement
ICP above 20 mmHg needs treatment
Just understand concept
what is cerebral perfusion pressure
pressure needed to ensure adequate brain tissue perfusion
CPP = MAP - ICP
Mean arterial pressure and pressure already in brain
If you increase MAP, you increase perfusion pressure
If someone is hypotensive, vs hypertensive how does this affect perfusion
3 types of ischemic stroke
- transient ischemic attack
- thrombotic stroke
- embolic stroke
what is an ischemic stroke
clot
what is transient
not permanent
2 types of hemorrhagic strokes
- intracerebral
- subarachnoid
what does hemorrhagic mean
bleed
usually from weakened vessel
what is a thrombotic stroke
cerebral thrombosis is a narrowing of the artery by fatty deposits called plaque. plaque can cause a clot to form, which blocks the passage of blood through the artery
what is an embolic stroke
an embolus is a blood clot of other debris circulating in the blood. when it reaches an artery in the brain that is too narrow to pass through, it lodges there and blocks the flow of blood
what is a hemorrhagic stroke
a burst blood vessel may allow blood to seep into and damage brain tissues until clotting shuts off the leak
what is a transient ischemic attack (TIA)
- caused by a TEMPORARY state of decreased blood flow in a portion of brain
- without acute infarction
- usually precursor to ischemic stroke
- TIA results in a sudden, brief decreased in brain function, typically last <1 hour
Not cell death associated with this
TIA assessment for the carotid system s/s
- loss of vision in one eye
- motor function (hemiparesis)
- numbness or loss of sensation
- sudden inability to speak
“veg vibes”
TIA assessment for the vertebrobasilar system s/s
- tinnitus
- vertigo
- vision (darkened, blurred, doubled)
- slurred speech
- difficulty swallowing
- loss of muscle control
- ptosis (eyelid droop)
- numbness or weakness
“drunk vibes”
how do we do management of a TIA
- platelet aggregation inhibitors
- treatment of arrhythmia
- treatment of hypertension
- anticoagulation
- statins
- reduction of risk factors
- surgical or endovascular intervention
for management of TIA with platelet aggregation inhibitors for low risk pts what do we give them
ASA
for management of TIA with platelet aggregation inhibitors for high risk pts what do we give them
dual therapy
ASA and Clopidogrel or Ticagrelor
for management of TIA when do we give anticoagulation therapy what conditions
afib, venous thromboembolism, mech heart valve
what are 3 things needing surgical intervention we can do for management of TIA
- carotid endarterectomy
- transluminal angioplasty
- extracranial-to-intracranial artery bypass
what is a carotid endarterectomy
is performed to prevent impending cerebral infarction. a tube is inserted above and below the blockage to reroute the blood flow. atherosclerotic plaque in the common carotid artery is removed. once the artery is stitched closed, the tube can be removed. a surgeon may also perform the technique without rerouting the blood flow.
what is a transluminal angioplasty - brain stent
brain stent used to treat blockage in cerebral blood flow. a balloon catheter is used to implant the stent into an artery of the brain. the balloon catheter is moved to the blocked area of the artery and then inflated. the stent expands due to the inflation of the balloon. the balloon is deflated and withdrawn, leaving the stent permanently in place holding the artery open and improving the flow of the blood.
Same concept as angio to the heart
But to the brain
This is becoming more of a common procedure
If not responding to other treatments
what is TIA/stroke prevention health management goals
- BP control
- Blood glucose control
- diet and exercise
- smoking cessation
- limiting alcohol consumption
- routine health assessment
what is TIA/stroke prevention surgical or endovascular intervention
- transluminal angioplasty
- carotid endarterectomy
- extracranial-to-intracranial artery bypass
- stenting of carotid artery
- surgical interventions for aneurysms as risk for bleedings
what is TIA/stroke prevention with antiplatelet agents
- aspirin 81-325 mg po daily
- clopidogrel (plavix)
- ticagrelor
- dipyridamole (persantine)
- combined dipyridamole and aspirin (aggrenox)
what is TIA/stroke prevention anticoagulation
- coumadin
- dabigatran (pradaxa)
- rivaroxaban (xarelto)
what is TIA/stroke prevention statins
- simvastatin (zocor)
- lovastatin (mevacor)
- what is a stroke or “brain attack”
- what happens to the brain cells
- when should treatment be given
- interruption of cerebral blow flow:
- blood clot blocks a blood vessel or artery
- blood vessel breaks - brain cells in immediate area die (min to hours) after the stroke starts = ischemia
- treatment given within 4.5 hours < damage
- late Rx may fail = further damage
describe an ischemic stroke +
causes
- partial or complete occlusion of cerebral blood flow
- causes: thrombus vs embolus
- area of injury: edema, tissue breakdown, small arterial vessel damage
- 87% of strokes
There is probably already damage done - we are not happy with this
CT is looking for a bleed to attribute stoke symptoms too
Determining if it is a hemorrhagic event or not - if no bleed its ischemic
what is thrombotic ischemic stroke
- atherosclerotic plaques
- occurs from injury to a blood vessel wall and formation of a blood clot
- causes narrowing the blood vessels - if becomes occluded infarction occurs
- extent depends on rapidity of onset, the size of the lesion, and the presence of collateral circulation
- most common
what is embolic ischemic stroke
- embolus lodges in and occludes a cerebral artery, resulting in infarction and edema of the area supplied by the involved vessel
- majority originate in the endocardial (inside) layer of the heart
- AF is associate w 4-5x increased risk
- onset of symptoms more rapid, recurrence is common unless underlying condition treated
hemorrhagic stroke
- leakage of blood - causing edema, compression of brain tissue, spasm of adjacent blood vessels
- often a sudden onset of symptoms, w progression over minutes to hours because of ongoing bleeding
- 15% of strokes
hemorrhagic stroke intracerebral
- within brain tissue
- commonly occurs with activity
- sudden onset w progression over min to hours
- symptoms: neurological deficits, headache, nausea, vomiting, decreased LOC, and HTN
- extent depending on the amount and duration of the bleeding
hemorrhagic stroke subarachnoid
- intracranial bleeding into the CSF filled space between the arachnoid and the pia mater membranes on the surface of the brain
- commonly caused by rupture of a cerebral aneurysm
“worst headache of life”
cerebral aneurysm
what is FAST acronym
Face - drooping
Arm - weakness
Speech - difficulty
Time - to call 911
motor function clinical manifestations of stroke
- most obvious effect of stroke
- include impairment of: mobility, resp function, swallowing and speech, gag reflex, self-care abilities
- an initial period of flaccidity
- may last from days to several weeks
- spasticity of the muscles follows the flaccid stage
when there is a right side of brain stroke describe signs
- paralyzed left side: hemiplegia
- left sided neglect
- spatial perceptual deficits
- tends to deny or minimize problems
- rapid performance, short attention span
- impulsive; safety problems
- impaired judgement
- impaired judgement
- impaired time concepts
when there is a left side of brain stroke describe signs
- paralyzed right side: hemiplegia
- impaired speech-language (aphasias)
- impaired right-left discrimination
- slow performance, cautious
- aware of deficits: depression, anxiety
- impaired comprehension related to language, math
communication clinical manifestations of a stroke
- aphasia
- dysphasia
- dysarthria
- agraphia
- alexia
- apraxia
what is aphasia and the diff kinds (4)
the total loss of comprehension and use of language
- expressive (broncos)
- receptive (wernicke’s)
- anomic or amnesic (difficulty finding correct names)
- global (expressive and receptive)
what is dysphasia
difficulty related to the comprehension or use of language and is due to partial disruption or loss
what is dysarthria
disturbance in the muscular control of speech
what is agraphia
loss of the ability to write
alexia
loss of the ability to read
what is a clinical manifestation of affect for stroke
- difficulty controlling their emotions
- emotional responses may be exaggerated or unpredictable
what is a clinical manifestation of intellectual function for stroke
- both memory and judgement may be impaired
- left-brain stroke: more likely to result in memory problem related to language
clinical manifestations of spatial-perceptual alterations (4)
- spatial - perceptual problems may be divided into four categories
1. incorrect perception of self and illness
2. erroneous perception of self in space
3. agnosia - inability to recognize an object by sight, tough, or hearing
4. apraxia - inability to carry out learned sequential movements on command
agnosia
inability to recognize an object by sight, tough, or hearing
apraxia
inability to carry out learned sequential movements on command
whats included in a rapid stroke assessment
- ALOC
- weakness, numbness, or paralysis
- speech or visual disturbances
- severe headache
- airway/resp distress
- increased or decreased HR
- unequal pupils
- HTN
- facial drooping on affected side
- diff swallowing
- seizures
- bladder or bowel incontinence
- n/v
- vertigo
- cap blood sugar
- SaO2
- history - similar event, onset
- meds
- risk factors
- family history: stroke, CVS disease
what is glasgow coma scale
1. what is best response
2. what is comatose client
3. what is totally unresponsive client
- best 15
- 8 or less
- 3
stroke interventions initial
- manage CAB
- ensure patent airway
- call stroke code or stroke team (5 min)
- remove dentures
- perform pulse ox
- maintain adequate oxygenation
- obtain IV access w normal saline (x2)
- maintain BP according to guidelines
- foley cath insertion
stroke interventions acute phase but asap
- perform baseline lab tests, glucometer
- maintain head and body position - position head midline
- elevate head of bed 30 degrees if no symptoms of shock or injury occur
- Pt NPO
- ongoing assessment of VS and neuro status: GCS, canadian neurological scale
- obtain CT scan immediately (25 min)
stroke diagnostic tests
- CT
- MRI (within 7 days)
- cerebral angiography (CTA)
- doppler ultrasound
- LP
- cardiac monitoring
- chest x-ray
- echocardiography
- lab values: coagulation, renal function, lytes, CBC, lipid profile, cardiac markers, liver function, toxicology, blood alcohol level
- swallowing assessment within 24 hours, NPO until completed
further on into the acute phase what do you do next
- anticipate thrombolytic therapy for ischemic stroke (60 min)
- antiplatelet agent (TIS/ischemic stroke) - single vs dual tx
- control hypertension
- fluid and electrolyte balance
- avoidance of hypervolemia
- pain management
- temp control
- assess for hyper/hypoglycemia
- cardiac monitoring for 24-48 hours
- institute seizure precautions
to control HTN for ischemic and hemorrhagic what do you do
labetalol, hydralazine
if a seizure occurs in a stroke what medications would you give them
phenytoin (dilantin) or levetiracetam (keppra)
not given prophylactically
for an ischemic stroke what thrombolytic therapy is initiated
- recombinant tissue plasminogen activator (tPA) - alteplase
- tenecteplase (TNK)
- mech thrombectomy
for an ischemic stroke why is thrombolytic therapy done
- used to reestablish blood flow through a blocked artery to prevent cell death in pts w acute onset of ischemic stroke symptoms
- must be administered within 4.5 hours of onset of clinical signs of ischemic stroke (up to 9 hours in consultation with stroke expert-requires advanced imaging)
- door to needle <30-60 min
- inclusion/exclusion criteria
- monitor VS
- accurate body wt
- no anticoagulant or antiplatelet drugs are given for 24 hours after thrombolytic therapy
- evaluation by physician - 10 min elapsed from arrival
- stroke or neurologic expertise contacted - less than or equal to 15 min elapsed
- interpretation of neuroimaging scan - less than or equal to 45 min elapsed
- start of IV thrombolytic treatment - less than or equal to 60 min elapsed
- consider stopping intervention: change in neuro s/s - consider intracranial hemorrhage - immediate non contract CT, systemic bleeding
thrombolytic drug inclusion criteria
- ischemic stroke w measureable neurologic deficit
- negative CT scan
- onset of symptoms more than 1 hour and less than 4.5 hours before alteplase administration
- > 185/110 mm Hg
- 18 yrs +
want to rule out TIA
thrombolytic drug exclusion criteria
- history of intracranial hemorrhage
- GI bleed, stroke or serious head/spinal trauma in past 3 mo
- active internal bleeding
- recent major surgery within 14 days
- BP >185/110 refractory to therapy
- BG below 2.7 mmol/L or above 22.2 mmol/L
- elevated PTT>40 or INR 1.7
- low platelet count
- therapeutic doses of low molecular wt heparin received within 24 hours
- current use, within 48 hours, of a direct thrombin inhibitor or direct factor Xa inhibitor w evidence of anticoagulant effect
- evidence of hemorrhage on CT
thrombolytic drug assessment and care
- monitor for bleeding
- neuro assessment
- VS - maintain bp
- bedrest
- no IM injections
for an ischemic stroke describe mech thrombectomy
- within 6 hours of onset of symptoms (up to 24 hours in some circumstances)
- acute ischemic stoke - anterior or posterior circulation
- +/- thrombolytic therapy for the same ischemic stroke event
criteria for mech thrombectomy for ischemic stroke
- CT, CTA, CT perfusion parameters (RAPID) - may require repeat imaging
- national institute health stroke scale
- ASPECT
describe ischemic stroke merci embolus retriever
- removes blood clots in pts who are experiencing ischemic strokes. retriever is a long, thin wire that is threaded through a catheter into the femoral artery. wire is pushed through the end of the catheter up to the carotid artery. wire reshapes itself into tiny loops that latch onto the clot, and the clot can be then pulled out. to prevent the clot from breaking off, a balloon at the end of the catheter inflates to stop blood flow through the artery.
what is ischemic stroke post emergent phase interventions minus drug therapy
- aspirin is used within 24-48 hrs of stroke (consider GI protection)
- DVT prophylaxis
- platelet inhibitors and anticoagulants may be used in thrombus and embolus stroke pts after stabilization
- BP control
- continuous cardiac monitoring
- CT at 24 hours
- sheath site assessment (including distal pulses)
what is ischemic stroke post emergent phase interventions - antiplatelet agents meds
- aspirin 81-325 mg po daily
- clopidogrel (plavix)
- ticagrelor
- dipyridamole (persantine)
- combined dipyridamole and aspirin (aggrenox)
“DACT”
what is ischemic stroke post emergent phase interventions - anticoagulation
- coumadin
- dabigatran (pradaxa)
- rivaroxaban (xarelto)
what is ischemic stroke post emergent phase interventions - statins
- simvastatin (zocor)
- lovastatin (mevacor)
describe acute phase for hemorrhagic stroke
- anticoagulants and antiplatelets are contraindicated (D/C if taking these meds and reverse as needed)
- ICP management
- fluid and lyte management
- +/- seizure precautions
- cardiac monitoring for 24-48 hours
- reduce vasospasm - CCB
what is main drug therapy for acute phase for hemorrhagic stroke
for management of HTN
maintain BP normal to high
systolic bp <140 mm Hg
labetalol, hydralazine
what are 4 hemorrhagic stroke surgical interventions
- evacuation of hematoma
- surgical resection
- clipping
- coiling
what is a craniectomy
an excision of a portion of the skull
clipping of aneurysm
gugliemi detachable coli
how to manage ICP
- assess VS - manage BP
- ICP monitoring
- external ventricular drain
- CSF drainage
- hyperventilation
- sedation
- resp support (adequate oxygenation, mech vent)
- elevate HOB 30 degrees
- control vomiting
- treat hyperthermia
- monitor fluid status
- treat headache
- surgical interventions
- nutritional support
what do we need to keep in mind for hemorrhagic stroke post emergent phase
- assess need for antiplatelet and/or anticoagulant
- aspirin - 48 hours post
- other antiplatelets - 1-2 wks
- anticoagulants - at least 4 wks post - BP control - goal bp of <130/80 mmHg
- DVT prophylaxis - intermittent pneumatic compression devices
- continuous cardiac monitoring
- clinical deterioration or worsening of LOC - urgent repeat of CT
considerations for impaired swallowing
- have swallowing assessment performed
- have client at 90 degrees for meals
- head forward flexion for swallowing
sitting upright 30 min after meals
