Define cerebrovascular disorder
umbrella term referring to the functional abnormality of the CNS that occurs when the blood supply to the brain is disrupted
What is the primary cerebrovascular disorder?
Stroke; nearly 800,000 people in the US experience one each year; stroke is also the leading cause of long-term disability in the US
Name three non modifiable risk factors for stroke.
age (>55), gender, race (African American)
Name some modifiable risk factors for stroke.
HTN, CVD, hyperlipidemia, elevated hematocrit, obesity, DM, oral contraceptives, smoking/drug/alcohol abuse
What is another name for ischemic stroke?
cerebrovascular accident CVA, brain attack
Define CVA
decreased blood supply to a part of the brain caused by a rupture, occlusion, or stenosis of a blood vessel; high reoccurrence; onset may be slow or gradual
What percentage of CVA survivors are permanently disabled?
50%
What is a transient ischemic attack?
temporary neurologic deficit resulting from temporary impairment of blood flow; warning of an impending stroke
What are some preventive treatments for stroke?
health diet, exercise, prevention/tx of periodontal disease, carotid endarterectomy, anticoagulant therapy, anti platelet therapy, statins
What are some types of ischemic stroke?
-Large artery thrombosis
-Small penetrating artery thrombosis
-Cardiogenic embolism
-Cryptogenic
Flip for a fun infographic on Stroke
Give a brief pathophysiology of ischemic stroke
Ischemic cascade begins when cerebral blood flow is disrupted and decreases to <25 mL/100 g of blood per minute. Mitochondria switch to anaerobic respiration, creating large amounts of lactic acid, lowering pH as well as insufficient production of ATP. Me
What is the penumbra region?
area of low cerebral blood flow that exists around the area of infarction; this area may be salvaged with timely intervention
What role do calcium and glutamate play in ischemic stroke?
increased intracellular calcium and release of glutamate activates damaging pathways that result in the destruction of cell membrane, the release of more Ca and glutamate, vasoconstriction, and generation of free radicals
What are the manifestations of ischemic stroke?
-numbness or weakness of the face, arm, or leg; especially on one side of the body
-confusion or change in mental status
-trouble speaking or understanding speech
-visual disturbances
-difficulty walking, dizziness, loss of balance or coordination
-sudden
Symptoms & Behaviors of 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 judgment
impaired time concepts
Symptoms & Behaviors of left-brain damage
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
What is the difference between hemiplegia and hemiparesis
hemiplegia - paralysis of one side of the body or part of it
hemiparesis - weakness of one side of the body or part of it
Define aphasia
inability to express oneself or to understand language
Define dysarthria
difficulty in speaking caused by paralysis of the muscles responsible for producing speech
Define dysphasia
impaired speech
Define expressive aphasia
inability to express oneself
Define receptive aphasia
inability to understand language
Define global aphasia
combination of expressive and receptive aphasia
Define apraxia
inability to perform a previously learned action; patient may make verbal substitutions for desired syllables or words
Define agnosias
deficits in the ability to recognize previously familiar objects perceived by one or more of the senses
Medical management for strokes
-prompt diagnosis and tx
-assessment of stroke
-thrombolytic therapy (tPA)
-elevate HOB unless contraindicated
-maintain airway and ventilation
-continuous hemodynamic monitoring and neurologic assessment
Potential complications of ischemic stroke
tissue ischemia, aspiration pneumonia, UTI, cardiac dysrhythmias, complications of immobility, hyperglycemia
Surgical prevention of ischemic stroke
CEA - removal of an atherosclerotic plaque or thrombus from the carotid artery to prevent stroke in patients with occlusive disease of the extra cranial cerebral arteries
Nursing Assessment for Ischemic Stroke
-change in LOC or responsiveness
-presence or absence of voluntary or involuntary movements
-eye opening, pupil size and reaction
-color/temp of face and extremities
-quality and rate of pulses and respiration
-ability to speak
-volume of fluids ingested/
Nursing DX for ischemic stroke
-impaired physical mobility r/t hemiparesis
-acute pain r/t hemiplegia and disuse
-self-care deficits r/t stroke sequelae
-impaired physical comfort r/t altered sensory perception
-impaired swallowing
-impaired urinary elimination
Major goal for ischemic stroke patients
improved mobility, avoidance of shoulder pain, achievement of self-care, relief of discomfort, prevention of aspiration, continence of bowel and bladder, decreasing confusion, achieving form of communication, maintaining skin integrity, restored family fu
Interventions for ischemic stroke
-improve mobility and prevent joint deformities
-establish exercise program
-prepare for ambulation
-prevent shoulder pain
-enhance self-care
-adjusting physical changes
-assisting with nutrition
-attaining bladder and bowel control
-improving thought pro
Describe hemorrhagic stroke
caused by bleeding into the brain tissue, the ventricles, or the subarachnoid space
Possible causes of hemorrhagic stroke
May be caused by spontaneous rupture of small vessels primarily related to hypertension; subarachnoid hemorrhage caused by a ruptured aneurysm; or intracerebral hemorrhage related to amyloid angiopathy, arterial venous malformations (AVMs), intracranial a
Briefly describe the pathophysiology behind hemorrhagic stroke
dependent on cause and type of cerebrovascular disorder; symptoms are produced when a primary hemorrhage, aneurysm, or AVM presses on nearby cranial nerves or brain tissue or when an aneurysm or AVM ruptures causing subarachnoid hemmorhage
What are the two causes of disruption to normal brain metabolism associated with hemorrhagic stroke?
1. increase in ICP resulting from the sudden entry of blood into subarachnoid space, compressing and injuring brain tissue
2. secondary ischemia of the brain resulting from reduced perfusion pressure and vasospasm
Differentiate between an intracerebral and subarachnoid hemorrhage
intracerebral - bleeding into the brain tissue, commonly seen in pt's with HTN, CAD
subarachnoid - bleeding into the subarachnoid space, may occur as a result of AVM, intracranial aneurysm, trauma, or HTN
Clinical manifestations of hemorrhagic stroke
-similar to ischemic stroke
-SEVERE HEADACHE
-early and sudden changes in LOC
-vomiting
Complications associated with hemorrhagic stroke
cerebral hypoxia, decreased blood flow, vasospasm, increased ICP, HTN
Medical management of hemorrhagic stroke
-Prevention: control of hypertension.
-Diagnosis: CT scan, cerebral angiography, lumbar puncture if CT is negative and ICP is not elevated to confirm subarachnoid hemorrhage.
-Care is primarily supportive.
-Bed rest with sedation.
-Oxygen.
-Treatment of v
Nursing Assessment for hemorrhagic stroke
-altered LOC
-sluggish pupillary rxn
-motor and sensory dysfunction
-cranial nerve deficits
-speech difficulties
-visual disturbances
-headache and nuchal rigidity
Nursing DX for hemorrhagic stroke
-ineffective tissue perfusion r/t bleeding or vasospasm
-anxiety r/t illness and or medically imposed restriction
Nursing Planning for hemorrhagic stroke
-Improved cerebral tissue perfusion
-Relief of sensory and perceptual deprivation
-Relief of anxiety
-The absence of complications
Nursing interventions for hemorrhagic stroke
-optimize cerebral tissue perfusion
-implement aneurysm precautions
-relieve anxiety
-monitor for complications (seizures, hydrocephalus, rebleeding, hyponatremia)
-promote home and community-based care
What is tPA used for and how does it work?
Tissue Plasminogen Activator
Treating ischemic strokes
Dissolves clots by generating plasmin, which digests the fibrin strands and restores blood flow.
What inclusion criteria are necessary before the use of tPA?
Administered within 3 hours after ischemic stroke.
Age > 18 but < 80 years old.
No history of both diabetes AND stroke.
No anticoagulant medications.
NIHSS is < 25
Non-contrast CT showing no hemorrhage and reviewed by a radiologist and stroke neurologist.
What is the dosing for tPA when used to treat an ischemic stroke?
0.9 mg/kg; maximum does 90 mg
10% of the total does - IV bolus over 1 minute
Remaining 90% infused over 60 minutes
Your Pt. had an ischemic stroke and weighs 138 lbs. What will the rate be for tPA administration?
138 lbs = 62.7 kg
62.7 x 0.9 mg = 56.4 mg
10% of 56.4 mg = 5.6 mg IV bolus
5.6 mL x 60 min/hour = 336 mL/hour
56.4 mg - 5.6 mg bolus = 50.8 mg
50.8 mL x 1 hour = 50.8 mL/hour
What is the antidote for tPA?
aminocaproic acid
10 g in 250 mL NS IV over 1 hour
How should a Pt. be monitored post tPA administration?
First 24 hours > risk of hemorrhage, so no anti-platlet meds or heparin during this time.
Vitals every 15 min for 2 hours, then every 30 min for 6 hours, then every 60 min for 16 hours.