Stroke Chapter 58
Heart conditions associated w/ embolic stroke include:
A-fib. Infective endocarditis. Rheumatic heart disease.
_____ can identify cervical and cerebrovascular occlusion, atherosclerotic plaques, and malformations of vessels
Angiography
Treatment of Hemorrhagic Stroke
Antihypertensive and Anti-epileptics. Craniotomy, evacuation of clots, coiling, clipping.
Plaque Ischemic Stroke
Blockage by plaque.
Stroke may also be referred to as what 2 things?
Brain attack. C.V.A.
Posterior cerebral:
Hemianopsia, visual hallucination, spontaneous pain, motor deficit, nystagmus on NIH stroke scale.
What is the primary reason for avoiding certain drug treatments for stroke?
Hemorrhage
Stenosis
Ischemic strokes can also be caused by stenosis, or narrowing of artery due to buildup of plaque and blood clots along the artery wall.
Assessment of stroke -Objective data
LOC, motor abilities, CN function, sensation, proprioception, cerebellar function, deep tendon reflexes.
Anterior cerebral:
Motor and/or sensory deficit (contralateral), sucking or rooting reflex, rigidity, gait problems, loss of proprioception and fine touch.
Acute intervention for Stroke -Musculoskeletal system
Prevent contractures and muscular atrophy. Passive ROM begun on first day, if subarachnoid hemorrhage movement in extremities only, special attention to paralyzed or weak side.
What modifiable risk factor nearly DOUBLES the risk of stroke?
Smoking
TIA Manifestation
Visual: blurry vision, diplopia, blindness in one eye, tunnel vision. Motor: weakness, ataxia. Sensory: numbness of face, arm, hand, vertigo. Speech: aphasia, dysarthria.
Two Forms of Stroke
1. Ischemic: blockage of a blood vessel supplying the brain. 2. Hemorrhagic: bleeding into or around the brain
if blood flow to the brain is totally interrupted (ex: cardiac arrest), neurological metabolism is altered in __ seconds, metabolism stops in __ min. , and cellular death occurs in __ min.
30 seconds. 2 minutes. 5 minutes.
If a stroke is caused by hemorrhage...
A CT (non-contrast) can show evidence of bleeding into the brain almost immediately after stroke symptoms appear.
Embolic Stroke
A stroke caused by an embolus (ischemic stroke).
Aneurysm
A type of hemorrhagic stroke. Is a weak or thin spot on an artery wall. Overtime, these weak spots stretch or balloon out under high arterial pressure. The thin walls of these ballooning aneurysms can rupture and spill blood into the space surrounding brain cells.
Rehabilitative care for stroke
After stroke stabilized for 12 to 24 hours, collaborative care shifts from preserving life to lessening disability and attaining optimal function.
Nonmodifiable risk factors include:
Age, gender, ethnicity, or race and heredity. More common in men than women. More women than men die from strokes.
Acute intervention for Stroke Cardiovascular system
Aimed at maintaining homeostasis, nurse must perform cardiac assessment, manage infusions and monitor fluid balance. Measures to prevent DVT are often implemented. Monitor VS, cardiac rhythms, lung sounds for crackles and rhonchi, heart sounds for murmurs; Calculate I&O, Regulate IV fluids, adjust fluid intake to meet pt needs
Drug Alert: Ticlopidine(Ticlid) and Clopidogrel(Plavix)
All health care providers and dentists must be informed if taking this drug, especially before major dental procedures or surgery. May be d/c 10 to 14 days before if antiplatelet effect is not desired.
Measures to prevent development of thrombus or embolus are used in pts at risk for stroke. (Drug therapy)
Antiplatelets chosen treatment to prevent further stroke in pts who have had TIA r/t atherosclerosis. Aspirin(Asa) most frequently used. dose of 81-325mg/day. Ticlopidine, clopidogrel, Plavix (Risk for GI bleed, Combined dipyridamile and aspirin(Aggrenox).
MRI
Are more sensitive than CT for other types of brain disease, such as brain tumor, that might mimic a stroke. MRI cannot be performed in patients with certain types of metallic or electronic implants.
Blood Clots
Are the most common cause of artery blockage and brain infarction.
Problems with Clotting
Becomes more frequent as people age.
Homonymous hemianopsia
Blindness in the same half of each visual field, is a common problem after a stroke.
When Do Brain Cells Die
Brain cells die when they no longer receive oxygen and nutrients from the blood or there is sudden bleeding into or around the brain.
Surgical Treatment for Ischemic Stroke
Carotid endarterectomy. Carotid artery angioplasty with stenting. Transluminal angioplasty.
Health promotion for stroke
Control HTN and diabetic symptoms. A fib: anticoagulant and stop smoking.
Vertebral:
Cranial nerve deficits, diplopia, dizziness, nausea, vomiting, dysarthria, dysphagia, and/or coma.
What Happens in Atherosclerosis?
Deposits of plaque build up along the inner walls or large and medium-sized arteries, causing thickening, hardening, and loss of elasticity of artery walls and decreased blood flow.
Assessment of stroke -Subjective data
Description of current illness include duration and onset. Hx of similar symptoms previously experienced, risk factors and other illnesses s/d HTN, family hx of stroke of CVD. Current meds.
Middle cerebral:
Dominant side: Aphasia, motor and sensory deficit, hemianopsia. Nondominant side: Neglect, motor and sensory deficit, hemianopsia.
Time Sensitivity of Stroke
Effective therapies for stroke are available, but they lose their effectiveness if not given within the first 3 to 4.5 hours after onset of stroke.
Modifiable risk factors cont...
Excessive alcohol consumption, women more than 1 drink/day and men more than 2/day. Illicit drug use, esp. cocaine. Obesity, physical inactivity. Early form of birth control pills that contain high levels of progestin and estrogen. T.I.A.s
S/S of Stroke: FAST
F- face drooping (ask pt. to smile). A- arm weakness (ask pt. to raise both arms). S- speech difficulty (ask pt. to complete a sentence). T- time! to call 911.
Modifiable Risk Factors:
HTN: the single most important modifiable risk factor, stroke risk can be reduced by 50% w/ appropriate tx of HTN. Heart disease, including A-FIB, MI, cardiomyopathy, cardiac valve abnormalities. Diabetes mellitus. Serum cholesterol. Smoking.
Right Brain Damage
Hemiplegia on left side, 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
Hemiplegia on right side, impaired speech and language, aphasia, impaired right/left discrimination, slow performance, cautious, aware of deficits, depression, anxiety, impaired comprehension related to language and math.
2/3 of thrombotic strokes are associated with what 2 health problems??
Hypertension and Diabetes.
Acute care of Ischemic stroke
In initial evaluation, single most important point is onset of symptoms. Begins with managing ABCs, high BP is common immediately after stroke and may be protective response, Suction secretions as prescribed but no longer than 10 sec to prevent increasing ICP.
Aphasia: Global Aphasia-
Inability to communicate; severe communication difficulties.
Aphasia: Expressive Aphasia-
Inability to produce language ("express self"). Damage occurs in Broca's area of the frontal brain. Pts frequently speak in short phases that make sense but produced w/ great effort.
Spatial-Perceptual Alterations cont..
Incorrect perception of self and illness-damage to parietal lobe. Spatial perception- pt has difficulty in judging distances. Agnosia- the inability to recognize an abject by sight, touch, or hearing. Apraxia- the inability to carry out learned sequential movement on command.
Hypertension and High Blood Pressure
Increases the risk that a brittle artery wall will give way and release blood into the surrounding brain tissue.
Transluminal angioplasty
Insertion of a balloon to open a stenosed artery in the brain and improve blood flow. Involves intravascular placement of stent in attempt to maintain patency of artery.
Blood is supplied to the brain by 2 major pairs of arteries: what are they?
Internal carotid arteries: anterior circulation. Vertebral arteries: posterior circulation.
Occurrence of TIA
Is a warning sign that the person is at risk for more serious and debilitating stroke.
Thrombotic Stroke
Is caused by thrombosis, the formation of a blood clot in one of the cerebral arteries that stays attached to the artery wall until it grows large enough to block blood flow.
The Process of Clotting
Is necessary and beneficial throughout the body because it stops bleeding and allows repair of damaged areas of arteries or veins. However, when clot develop in the wrong places within an artery they can cause devastating injury by interfering with blood flow.
Computed Tomography
Is the most widely used imaging procedure. It creates a series of cross sectional images of the head and brain. It is the most commonly used diagnostic technique for acute stroke.--NON-CONTRAST. CT with Angio.
A stroke occurs when there is an interruption in one of these 2 things?
Ischemia: atherosclerosis, a hardening and thickening of the arteries, is the major cause of ischemic stroke. It can lead to thrombus formation and emboli. Hemorrhage: to a part of the brain (which is why its important NOT to give anticoagulant if it is r/t hemorrhage).
CT's Unique Diagnostic Benefits
It will quickly rule out a hemorrhage. Can occasionally show a tumor that might mimic a stroke. May show evidence of early infarction. Infarctions generally show up on a CT scan about 6 to 8 hours after the start of stroke symptoms.
Hemorrhagic Stroke
Less common. Happens when an artery in the brain bursts, blood spews out into the surrounding tissue and upsets not only the blood supply but the delicate chemical balance neurons require to function.
Aphasia:
Loss of ability to understand or express speech, caused by brain damage. Occurs when a stroke damages the dominant hemisphere of the brain types include: receptive and expressive and global.
Aphasia: Receptive Aphasia-
Loss of comprehension ("receive comprehension"). Injury involves Wernicke's area in the left temporal lobe (usually). Pts may speak in long sentences that have no meaning, unable to communicate verbally.
Akinesia:
Loss of skilled voluntary movement, causes motor deficits including impairment of mobility, respiratory function, swallowing and speech, gag reflex, self-care abilities.
The Benefit of MRI over CT Scan
MRI is more accurate and earlier in diagnosis of infarction, especially for smaller strokes, while showing equivalent accuracy in determining when hemorrhage is present.
Surgical therapy in pt w/ ischemic stroke
Mechanical embolus removal in cerebral ischemia (MERCI) retriever. The retriever goes to the artery that is blocked, directly to the site of the problem and pulls the clot out.
Ischemic Stroke
More common and accounts 80% of the time. Occurs when an artery supplying the brain with blood becomes blocked, suddenly decreasing or stopping blood flow and ultimately causing brain infarction.
Stroke is more common in males or females? and which gender is more likely to die from a stroke?
More common in males. Women are more likely to die from it bcause of the greater number of women over age 65.
Acute intervention for Stroke Neurological system
Must be monitored closely to detect changes suggesting extension of the stroke s/a increased ICP.
Glia
Nervous system cells that support and protect neurons form a blood brain barrier which is an elaborate meshwork that surrounds blood vessels and capillaries and regulates which elements of blood can pass through the neurons.
In a Healthy Functioning Brain...
Neurons do not come into direct contact with blood. The vital oxygen and nutrients the neurons need from the blood come to the neurons across the thin walls of the cerebral capillaries.
Intracerebral Hemorrhagic Stroke
Occurs when a vessel within the brain leaks blood into the brain itself. Most often, there is a sudden onset of symptoms, w/ progression over minutes to hours because of ongoing bleeding. prognosis of intracerebral hemorrhage is poor. HTN most common cause, other causes include anticoagulants.
Subarachnoid Hemorrhagic Stroke
Occurs when there is intracranial bleeding into the cerebrospinal fluid. Commonly caused by a ruptured cerebral aneurysm, other causes include trauma and illicit drug (cocaine) use. Deadly. Viewed as "silent killer", since patients do not have signs until rupture has occurred.
What Happens in Subarachnoid Hemorrhage?
One of the small arteries within the subarachnoid space bursts, flooding the area with blood and contaminating the CSF. Since CSF flows throughout the cranium, within the spaces of the brain, this type of stroke can lead to extensive brain damage.
A-fib Patient
Oral anticoagulation can include warfarin(Coumadin), Rivaroxaban(Xarelto).
The brain requires a continuous supply of blood to provide ____ and ____ that neurons need to function
Oxygen. Glucose.
Acute care of ischemic stroke Cont.
Pain management. control fluid and electrolyte. Neuro assessment for signs of increased ICP. Position on the side with HOB 10 to 30º, transfer to stroke center,
Carotid endarterectomy
Performed to prevent impending cerebral infarction. Atherosclerotic plaque in the common carotid artery is removed. MERCI retriever. DSP/ESP.
Arteriovenous Malformation or AVM
Person with AVM has an increased risk of hemorrhagic stroke. AVM are a tangle of defective blood vessels and capillaries within the brain that have thin walls and therefore can rupture.
Hemorrhage also occurs when arterial walls break open.
Plaque- encrusted artery walls eventually lose their elasticity and become brittle and thin, prone to cracking.
After pt is stabilized and to prevent further clot formation, pts with stroke caused by thrombi and emboli may be treated w/ what?
Platelet inhibitors and anticoagulants. Warfarin(Coumadin),Aspirin, ticlopidine, clopidogrel.
Dysarthria:
Poor articulated speech due to disturbance in muscular control.
Affect:
Pts may hay have difficulty controlling their emotions. Both memory and judgment may be impaired as a result of stroke.
Drug therapy for ischemic stroke
Recombinant tissue plasminogen activator (tPA) must be admin 3-4.5 hours of onset(used to reestablish blood flow to prevent cell death and not used in pt w/ GI bleed). Pts screened carefully before given tPA including a noncontrast CT or MRI, to rule out hemorrhagic stroke, blood tests for coagulation disorders and history of GI bleed, stroke or head trauma.
A number of surgical interventions are used to treat hemorrhagic stroke includes
Resection, clipping of an aneurysm, and evacuation of hematomas, procedure depends on cause.
Subarachnoid Space
Separates the arachnoid membrane from the underlying pia mater. It contains CSF as well as the small vessels that supply the outer surface of the brain.
Transient Ischemic Attack
Sometimes called a ministroke, starts just like a stroke but then resolves leaving no noticeable symptoms or deficits.
Stroke
Stroke occurs when there is ischemia-inadequate blood flow- to a part of the brain or hemorrhage into the brain that results in death of the brain. It is also the 4th most common cause of death in the U.S..
Signs and Symptoms of Stroke: Sudden trouble walking, dizziness, loss of balance or coordination. Sudden severe headache with no known cause.
Sudden numbness or weakness of face, arm, leg , usually on one side of the body. Sudden confusion, trouble speaking, or understanding speech. Sudden trouble seeing in one or both eyes.
Subarachnoid Hemorrhagic Stroke Sign
Sudden onset of a severe headache that is different from a previous headache and typically the "worst headache of ones life" is a characteristic symptom of a ruptured aneurysm.
Factors that affect blood flow to the brain include:
Systemic BP. Cardiac output. Blood viscosity.
Communication deficits:
The Left hemisphere is dominant for language skills in right-handed persons and in most left-handed persons. Language disorders involve expression and comprehension of written and spoken words.
Atherosclerosis
The most common blood vessel disease that causes stenosis.
Motor Function Deficit
The most obvious effects of a stroke. They follow specific patterns. because the pyramidal pathway crosses at the level of the medulla, a lesion of one side of the brain affects motor function on the opposite side of the body (contralateral.
Thrombolytic Therapy
The only proven acute stroke therapy for ischemic strokes. It cannot be used until the doctor can confidently diagnose the patient is suffering from an ischemic stroke. Why? Because it might increase bleeding and make hemorrhagic stroke worse.
TIA Teaching
The patient should assume that all stroke symptoms signal an emergency and should not wait to see if they go away. TIA overall symptoms are gone in less than 24 hours usually.
What is collateral circulation?
The vessels in the brain make an "alternate route" for blood flow to reach damaged areas.
Nursing interventions to optimize musculoskeletal function includes
Trochanter roll at hip to prevent external rotation. Hand cones to prevent hand contractures. Arm support w/ slings and lap board to prevent shoulder displacement. Posterior leg splints, foot boards, or high top tennis shoes to prevent foot drop. Hand splints to reduce spasticity.
Magnetic Resonance Imaging
Uses magnetic fields to detect subtle changes in the brain tissue content. MRI can show slowing of diffusion through the damaged brain tissue within the first hour after the onset of stroke.
Acute intervention for Stroke -Respiratory
Vulnerable to respiratory problems including, atelectasis, airway obstruction, and aspiration pneumonia. To prevent complication from mechanical ventilation, having nurse provide oral care at the min of every 2 hours may reduce the occurrence of ventilator assisted pneumonia.
Embolus
When a clot that forms in a part of the body other than the brain travel throughout blood vessels and become wedged in a brain artery. The clot often forms in the heart.
When Does Stroke Occur?
When the blood supply to part of the brain is suddenly interrupted or when a blood vessel in the brain bursts, spilling blood into the spaces surrounding brain cells.
Hemorrhagic Stroke
do NOT administer aspirin or other anticoagulants. These strokes result from bleeding into the brain tissue itself or into the subarachnoid space or ventricles. Accounts for 15% of all strokes.
Average Duration of TIA
is a few minutes. For almost all TIAs, the symptoms go away within an hour. There is no way to tell whether the symptoms will be just a TIA or persist and lead to death or disability.
Treatment for Ischemic Stroke
rTPA, aspirin, diuretics, benzodiazepines, anti-epileptics, calcium channel blockers, stool softener, analgesics. Tpa tx within 4.5 hours from symptom onset--bleeding can occur if delayed.