Stroke Flashcards
Stroke occurs when there is _________ to a part of the brain that reults in the death of brain cells
Ischemia
Stroke is the ____ leading cause of death in canada
3rd
Cerebral blodd lfow myust be mainatianed at ______ % of cardiac output
20%
Cellular death in the brain can occur in as few as ______ in the event of no blood flow
5 minutes
Cerebral autoregulation
Changes in diameter of cerebral blood vessels in response to changes in pressure so the pressure in the brain stays constant
May be impaired following cerebral ischemia
Circle of Willis
A redundancy of the brain that allows blood to continue to flow through the brain, even if a major vessel is blocked
Not necessarily entirely effective, especially over long period of time
Common areas where athersclerosis will build up
Plaque builds up along forks in the blood vessels
How does HTN affect blood flow to the brain?
Reduceds blood flow by vasoconstirction and vessel stiffening (stenosis)
Factors affecting blood flow to brain
Cardiac output (Must decrease by 1/3 before brain is affected
Blood viscosity (Increased = less flow to the brain)
What causes cerebral ischemia
Thrombosis, mostly caused by athersclerosis
Plaque builds up in stiffened vessels, platelets form thrombus on plque until vessel is obstructed
Embolic stroke
Embolus that forms outside of the brain (usually plaque), then travels up and occludes vessel in brain
associated with chronic Afib
- Blood pools in atrium forming small clots that travel through circulation and enter brain
Sources of embolism
Afib (Allowing for pooling of blood in atrium forming clots)
Mechanical valve (rougher surface increasing risk for clots)
Bacterial/non endocarditis
Tumors that break
Air
Fat
Hemmorhagic Stroke
Rutprue of vessels caused by increased pressure
Most common cause is HTN
Slowest recovery
Ischemic strokes include
TIA (precursor)
Thrombotic (develops in the brain)w
Embolic (embolus
Hemmorrhagic Stroke, types and commonality
Intracerebral
Subarachnoid (bleeding in this space)
15% of all strokes
Anuerysm
Pouching of artery due to HTN
Which type of stroke results in decreased crervral perfusion and incread ICP?
All strokes can
TIA
Precursor
Temporary loss of neuro function
Usually lasting less than 15 minutes
Don’t know if it’s going to resolve or if it will progress into full Ischemic stroke
Ischemic stroke
85% of strokes
61% are thrombotic
24% are embolic
Symptoms of embolic strokes
Symptoms sudden, no chance to develop collateral circulation
Thrombotic stroke symptoms
Slow and progressive
may not have changes in LOC in 1st 24 hrs.
Extent of stroke dependent on
Size of lesion
presence of collateral circulation
Prognosis of embolic stroke?
Dependtant on amount and location of brain tissue affected
Intracerebral stroke
10% of H strokes
HTN is sig risk factior
Occurs DURING activity
Sudden onset with progression of symptoms of min-hours b’c of bleeding
- headache, n/v, sudden alteration in LOC, hypertension
Poor prognosis
Subarachnoid stroke
Intracranial bleeiding into CSF space
Often rupture of cerebral aneurysm (silent killer), can also be trauma or cocaine
headache, n/v, sudden alteration in LOC, hypertension
Poor prognosis
Hemiplagia, neck stiffness, Loss of consciousness
40% will die within first episode
Brocas aphasia
People with Broca’s aphasia have a clear understanding of language, but have trouble finding and saying the right words.
Global Aphasia
Loss of expressive and receptive
Clinical manifestations of stroke
Motor function
Communication
Affect
Intellectual function
Spatial-perceptual alterations
Elimination
Risk factors for stroke (Non-mod)
Age
Gender
Race
Family Hx (First degree releative)
Modifiable Factors for stroke
Smoking
Alcohol
Obesity
Inactivity
High Cholesterol
Illicit drug use
Oral contraceptives & HRT
Secondary dx that contirbute to increased risk factor for stroke
HTN - single most contributing factor to stroke
DM
Heart
Disease/CAD
All symptoms of stroke are contralateral EXCEPT
pupil dialation
Right-brain damage
Left hemiplegia
Left side neglect
Spatial perceptual deficits
Tends to deny/minimize problems
Rapid performance, short atention span
Diagnostics for stroke (IMPORTANT) **
When s/s of stroke appears
- Diag. studies confirm it’s a stroke
- Identify likely cause of stroke
CT is primary diagnostic
Spinal tap for a stroke?
RBC in CSF
LAb diagnostics for stroke
APT, PT, INR (Low more at risk for stroke, high means more at risk for bleeding) Platlets
Collaborative Care prevention
Management of those with high risk
Drug therapy
Antiplatelet drugs
Aspirin
Statins
Surgical therapy
carotid endarterectomy.
transluminal angioplasty.
stenting.
extracranial–intracranial bypass.
Carotid endarterectom
Brain Stent
Hallmark s/s of stroke
Weakness/numbness
Trouble speaking
Vision problems
Headache
Dizziness
Goals in stroke response
Preserving life
Prevent further brain damage
Reduce disability
Single most improtant point in a stroke pt hx is___hours after onset
3-4.5
What is important to assess when you suspect a pt has a hd a stroke
ABCs
VS
GCS (Neuro exam), PERRLA, LOC
Assessment findings in stroke
Altered LOC
Weakness, numbness, or paralysis
Speech/visual disturbances
Severe headache
HR change
Pupil differsences
Resp Distress
HTN
Facial droop
Difficulty swallowing
Seizures
incontinence
N/v
Vertigo
Fever
Projectile vomit is a sign of
Increased ICP
Our stroke intervention goal is
ABCD
Additional interventions for stroke
Open Airway (remove dentures)
Start IV
CT scan
Why is baseline importnat to establish at onset of stroke
To see if they are improving or getting worse
Interventions to HTN for ACUTE ischemic stroke
Response to maintain cerebral perfusion
- Use of BP medications are not recommended unless BP is markedly increased (systolic >220mmhg or MAP > 130mmhg why?
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Interventions for fluid electrolyte blaance in stroke
Adequate hydration to help perfusion
Hypotonic fluid can WORSEN cerebral edema
Fluid restriction (1.5-2L
Nursing response to cerebral edema
lift HOB
Decrease pain
Avoid seizures
don’t increase metabolsim of brain
Preventing aspiration in a stroke pt
Raise HOB
Pureed Diet (NPO until swallowing assessment)
Thickened fluids
Temperature and the brain
Every temp increase is 10% more increase metabolism in the brain
Medication intervention for ischemic stroke
tPA (alteplase)
Must be given 3-4.5 hours of onset of symptoms
Aspirin
Anticoagulant and antiplatlet
Assess neuro
Assess BP
Surg interventions for ischemic
Endovasculat TS (allows clot to be removed
Interventions for hemorrhagic stroke
Keep blood pressure in a normal to high normal range <160
Close monitoring for patients on blood thinner
May have reverse medication
Medication Treatment
Nimodipine
Surgical intervention can be considered
Clipping & coiling
Manifestations of acute changes in cerebral perfusion
Cushings Triad
Systolic BP increase
Pulse decrease
Resp decrease
Nursing invterventions for ICP
Medically induced coma
Decreased stimulation
Manitool
Hypertonic NS
Steroids (Reduce inflam)
BP meds
Why does ischemic stroke still increase ICP
primarily due to cerebral edema, which is brain swelling caused by the lack of blood flow to the affected area, leading to an increase in brain tissue volume within the rigid skull, thereby elevating pressure
