Stroke Flashcards
Stroke
Stroke occurs when there is ischemia (inadequate blood flow) to a part of the brain that results in the death of brain cells
Circle Of willis
If one artery becomes blocked (e.g., due to a clot in an ischemic stroke), the Circle of Willis can often reroute blood flow through alternative pathways.
Aterosclerosis
Is the buildup of fat, cholesterol, and other substances in and on the artery wall.
Which factors effect blood flow to the brain?
- Systemic blood pressure: high blood pressure reduces blood flow to the brain by vasoconstricting and stiffening those blood vessels. Which is why people with prolonged hypertension are at an increased risk for stroke.
- Cardiac Output: How much blood gets pumped into the body by
the heart. It has to be reduced by a 1/3 before the cerebral blood
flow will be affected. - Blood viscosity: A measure of how thick and sticky blood is and
how much it resists flowing. Increased viscosity decreases blood
flow to the brain.
Thrombosis
The main cause of stroke and this is caused by atherosclerosis, which causes plaques; these enlarge and cause stenoses, so veins don’t move or function very well; it alters the normal smooth blood flow. Most common cause of stroke in diabetics
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.
Embolism
Forms outside the brain, detaches, and travels through the cerebral circulation until it loges and occludes a cerebral artery. The most common embolus is plaque and is associated with chronic atrial fibrillation and blood pools in the poorly emptying atria, and tiny clots form in the left atrium and move through the heart and into cerebral circulation. Risk of Embolism increases with Age
a blood clot or 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.
Hemorrhage stroke
is a rupture of arteriole sclerotic and hypertensive vessels, so those vessels cannot take the pressure anymore and they rupture. This rupture causes bleeding into brain tissues and most common cause of this is hypertension, which usually produces extensive residual functional loss and has the slowest recovery
A burst blood vessel may allow blood to seep into and damage brain tissues until clotting shuts off the leak. It accounts for 15% of all strokes and it has a high mortality rate
Pathophysiology of CVA
Thrombosis -> Cerebral Infraction -> reduced Cerebral perfusion and Increased intracranical Pressure (ICP) -> Cerebral ischemia
Hypertension/Aneurysm -> Cerebral Hemorrahage -> reduced Cerebral perfusion and Increased intracranical Pressure (ICP) -> Cerebral ischemia
Transient Ischemic Stroke (TIA)
TIA – precursor to ischemic stroke
TEMPORARY loss of neuro function lasting <24 hours. Often <15min. Resolves within 1 hour.
Caused by microemboli (progressive cerebrovascular disease)
Who is at Risk for a TIA? : Hypertension, CV disease, Diabetes
Ischemic Stroke (85%)
- Thrombotic (61% of strokes)Occurs when artery providing blood to brain tissue is blocked—
intracranial thrombus
Symptoms slow and progressive; may not have changes in LOC in
1st 24 hrs.
- Embolic (24% of strokes)
Travelling embolus (often from heart – atrial fib, hx of MI)
Symptoms sudden, no chance to develop collateral circulation
Prognosis depends on amount and location of brain tissue affected.
Hemorrhagic Stroke (15%)
- Intracerebral (10%):
Hypertension is a significant risk factor
Occurs DURING activity (sports, physical activity)
Sudden onset with progression of symptoms of min – hours b/c of bleeding
headache, n/v, sudden alteration in LOC, hypertension
Poor prognosis: 30 day mortality rate to 40 to 80% with hemorrhagic strokes.
50% will die soon after the initial hemorrhage and 20% remain functionally independent at 6 months
- Subarachnoid:
Intracranial bleeding into CSF space
Often rupture of cerebral aneurysm (silent killer), can also be trauma or cocaine
headache, n/v, sudden alteration in LOC, hypertension, nuko rigidity
Poor prognosis: 40% of rupter aneurysm will die during the first episode and 15% will die from subsequent bleeding
Clinical Manifestations
- Motor function
- Communication
- Affect
- Intellectual function
- Spatial-perceptual alterations
- Elimination
Manifestations do NOT significantly differ between ischemic and hemorrhagic stroke
Manifestations depend on the LOCATION of the stroke in the brain
Risk Factors
Non-modifiable:
- Age
- Gender
- Race
- Family History
Modifiable/Lifestyle:
- Smoking
- Alcohol
- Obesity
- Inactivity
- High Cholesterol
- Illicit drug use
- Oral contraceptives & HRT
Contributing:
- HYPERTENSION
- diabetes
- Heart Disease/CAD
Right-brain damage
- 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 time concepts
Left-brain damage
- Paralyzed on right side: Hemiplegia
- Imparied speech-language (aphasias)
- Impaired right-left discrimination
- Slow performance, cautious
- Aware of deficits: depression, anxiety
- Impaired comprehension related to language, math
Diagnositcs
When symptoms of a stroke occur, diagnostic studies are done to
confirm that it is a stroke:
- identify the likely cause of the stroke.
- CT is the primary diagnostic test used after a stroke. *
Lab work – which ones?:
- CBC
- Lipid profile: lower means higher risk for ischemic stroke?
- PT
- INR
- Platelets
- Electrolights
- Blood glucose
- Renal and hepatic studies
For cardiac assessment:
- Electrocardiogram
- Chest x-ray
- Cardiac markers
- Echocardiographs
Why might we want to assess the heart when considering a stroke?
- Embolism starts in the heart and Atrial fib is main cause most of the time
Collaborative Care: prevention
- Management of those with high risk
- Drug Therapy
- Surgical therapy for Pts Hx of TIAs
Management of those with high risk
Diabetes mellitus
Hypertension
Smoking
High serum lipids
Cardiac dysfunction
Drug Therapy
Antiplatelet drugs
Aspirin:
Statins: Lower cholesterol
Surgical Therapy for PTs Hx of TIA
carotid endarterectomy.
transluminal angioplasty.
stenting.
extracranial–intracranial bypass.
Assessments
Cognition
Sensory status
Language and communication
Physical mobility
Nutrition
Elimination
Skin integrity
GCS
Eye opening
Motor response
Motor Activity
Verbal response
PERRLA
Vital Signs
Assessment Findings
Altered level of consciousness
Weakness, numbness, or paralysis
Speech or visual disturbances
Severe headache
↑ or ↓ heart rate
Respiratory distress
Unequal pupils
Hypertension
Facial drooping on affected side
Difficulty swallowing
Seizures (Cause damage and increase ICP)
Bladder or bowel incontinence
Nausea and vomiting
Vertigo
Fever
You are a nursing student on the medical unit at ARH caring for a 78 year old female with a history of type II diabetes, hypertension, atrial fib, and a hx of a TIA. She is admitted with a foot infection due to her unmanaged diabetes.
Mid-morning, her daughter calls you to the room saying her mom is acting funny and her face looks strange. You enter to room and notice the patient has right sided facial drooping and her speech is slurred (these were NOT present on your initial assessment) What do you do?
- Call the doctor
- vital signs
- Note the time and neurological symptoms
Our Interventional Goal is? Think ABCD
Airway
Breathing
Circulation: BP, HR, Pulse
Disability
- Single most important point in a stroke a patient’s history is TIME of onset
- Current standard is that all stroke patients will be assessed, have their acute health needs addressed, undergo diagnostic studies & receive thrombolytic therapy within 3 - 4.5 from onset of symptoms
Goal:
1. Preserving life
2. Preventing brain damage
3. Reducing disability
