Introduction Cva 8

7/29/2019 Introduction Cva 8

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INTRODUCTION

Cerebrovascular accident or Stroke ( also calledbrain attack) is a term used to describe neurologic

changes caused by an interruption in the blood supply to a part of the brain which precipitates

neurologic dysfunction lasting longer than 24 hours..

Two major types of stroke:

1. Ischemic stroke

- Is caused by a thrombotic or embolic blockage of blood flow to the brain.

- Begins when cerebral blood flow decreases to less than 25 mL per 100 g of blood per unit

- Middle cerebral artery is the most common site.

- Account for about 83% of all strokes

- Patient prognosis is much better in the case of ischemic stroke, as

some hemorrhagic strokes carry a chance of death as high as 50%.

5 different types based on the cause:

1. Large artery thrombotic strokes (20%)

2. Small penetrating artery thrombotic strokes (25%)

3. Cardiogenic embolic strokes (20%)

4. Cryptogenic strokes (30%)

5. Other (5%)

2. Hemorrhagic stroke

- also called cerebral hemorrhage, and it occurs when a vessel in the brain ruptures or begins

to bleed.

- Hemorrhagic stroke can cause severe damage, not only because it restricts blood flow like

an ischemic stroke, but also because the blood from the burst or damaged vessel can injure

the surrounding tissue.

- Account for the remaining 17% of all strokes

Cause and type of CVA:

1. Intracerebral Hemorrhage

-bleeding into the brain tissue, is most common in patients with hypertension and

cerebral atherosclerosis

2. Intracranial (Cerebral) Aneurysm

- is a dilation of the walls of a cerebral artery that develops a s a result of weakness in

the arterial wall

3. Arteriovenous Malformations

-caused by an abnormality in embryonal development that leads to a tangle of arteries

and veins in the brain that lacks a capillary bed

4. Subarachnoid Hemorrhage

- may occur as a result of an AVM, intracranial aneurysm, trauma, or hypertension

COMPARISON OF MAJOR TYPES OF STROKE

Item Ischemic Hemorrhagic

Causes

Main presenting

symptoms

Functional

recovery

Large artery thrombosis

Small penetrating artery thrombosis

Cardiogenic embolic

Cryptogenic (no known cause)

Other

Numbness or weakness of the face, arm, or

leg, especially on one side of the body

Usually plateaus at 6 months

Intracerebral hemorrhage

Subarachnoid hemorrhage

Cerebral aneurysm

Arteriovenous malformation

exploding headache

Decreased level of consciousness

Slower, usually plateaus at about

18 months
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Etiology and risk factors

1. ThrombosisThrombus- starts with damage to the endothelial lining of the vessel.

- Atherosclerosis is the primary culprit.

- common site is at the bifurcation of the common carotid into the internal

external carotid arteries

Thrombotic stroke is the most common type of stroke in people with diabetes.

2. EmbolismEmbolus- forms outside the brain, detaches, and travels through the cerebral circulation

until it lodges in and occludes a cerebral artery.

- Plaque is a common embolus.

- Chronic Atrial Fibrillation is associated with a high incidence of embolic stroke

The incidence of cerebral embolism increases with age.

3. HemorrhageIntracerebral hemorrhage- may be caused by the rupture of arteriosclerotic and

hypertensive vessels, which cause bleeding into brain tissue

- Aneurysms are another cause of hemorrhage

Hemorrhagic stroke usually produces extensive residual function loss and has the

slowest recovery of all types.

4.

Cerebral arterial spasm- reduces blood flow to the area of the brain supplied by the constricted

vessel

5. Hypercoagulable states6. Compression of cerebral vessels

Risk factors

1. Hypertension

2. Cardiovascular disease and atrial fibrillation

3. Diabetes mellitus

4. History of stroke

5. Carotid stenosis6. History of transient ischemic attacks (TIAs)

7. Hyperlipidemia

8. Cigarette smoking

9. Healy alcohol consumption

10.Cocaine use

11.Obesity

12.Type A personality

13.Sedentary lifestyle

14.High-dose estrogen oral contraceptives

15.Advancing age16.African American

17.Men

Clinical Manifestations

Early Warnings or TIAs

Impending Ischemic Stroke:

1. Transient hemiparesis

2. Loss of speech

3. Hemisensory loss

Thrombotic Stroke:


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Develop over minutes to hours to days.

Hemorrhagic Stroke:

1. Severe occipital or nuchal headaches

2. Vertigo or syncope

3. Paresthesias

4. Transient paralysis

5. Epistaxis

6. Retinal hemorrhages

Generalized Findings of Stroke unrelated to specific vessel sites

1. Hypertensive- most clients

2. Headache

3. Vomiting

4. Seizures

5. Changes in mental status

6. Fever

7. Changes on the electrocardiogram (ECG)

Specific deficits after Stroke

1. Hemiparesis (weakness) and Hemiplegia (paralysis)

- Usually caused by a stroke in the anterior or middle cerebral artery

2. Aphasia

- Affected by stroke in the left middle cerebral artery

Types:

a. Wernickes aphasia

b. Brocas Aphasia

c. Global Aphasia

3. Dysarthria

- Caused by cranial nerve dysfunction from a stroke in the vertebrobasilar artery or its

branches

4. Dysphagia

- Stroke in the territory of the vertebrobasilar system

5. Apraxia

- Stroke in several areas in the brain

6. Visual changes

7. Homonymous Hemianopia

8. Horner Syndrome

9. Agnosia

10.Unilateral Neglect

-caused by middle cerebral artery occlusion

Clinical manifestations include failure to

a. Attend to one side of the body

b. Report or respond to stimuli on one side of the body

c. Use one extremity

d. Orient the head and eyes to one side

11.Sensory Deficits

- From a stroke in the sensory strip of the parietal lobe supplied by the anterior or middle

cerebral artery

a. Hemisensory loss

b. Paresthesia

c. Proprioception

12.Behavioral changes

Stroke in the left cerebral:

a. Frequently slow

b.

Cautiousc. disorganized


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Stroke in the right cerebral:

a. Frequently impulsive

b. Overestimate their abilities

c. Decreased attention span

Stroke in the anterior or middle cerebral arteries:

a. Disturbances in memory, judgment, abstract thinking, insight, inhibition, and emotion

13. Incontinence

Diagnostic Findings

1. Ct Scan (Computed tomography scan)- demonstrates structural abnormalities, edema, hematomas, ischemia, and infarctions. A CT

scan is a useful diagnostic test for hemorrhagic strokes because blood can easily be seen.

However, damage from an ischemic stroke may not be revealed on a CT scan for several

hours or days and the individual arteries in the brain cannot be seen.

Nursing responsibilities:

1. Explain the procedure to the patient.

2. Instruct the patient to lie quietly throughout the procedure.

3. A review of relaxation may be used to patient with claustrophobia.

4. Sedation can be used if agitation, restlessness, or confusion interferes with a successful

study.

5. If a contrast agent may be used, the patient must be assessed for allergies with iodine/

shellfish.

6. Renal function should also be evaluated.

2. PET scan (Positron Emission Tomography)- provides data on cerebral metabolism and blood flow changes, especially in ischemic stroke


1. The patient is interviewed for pertinent medical history

2. Explain the procedure to the patient.3. Instruct the patient to undergo NPO for 4 hours.

4. Inform the patient that he May return to normal activity immediately after PET scan is

completed.

5. Instruct the patient to lie on the imaging bed and the patient's head is positioned

comfortably for scanning.

7. The patient voids if not catheterized. Allergies and history of diabetes or elevated blood

sugar are discussed. The patient's level of pain is evaluated. Renal function should also

be evaluated.

8. The patient is escorted to the restroom.

9. The patient is instructed to hydrate well and void frequently for the next few hours.

3.

Magnetic Resonance Imaging (MRI)- A diagnostic test that produces three-dimensional images of body structures using magnetic

fields and computer technology. It can clearly show various types of nerve tissue and clear

pictures of the brain stem and posterior brain. MRI of the brain can help determine

whether there are signs of prior mini-strokes. It shows areas of infarction, hemorrhage, AV

malformations, and areas of ischemia.



2. Ask patient for allergies of any kind, such as allergy to iodine or x-ray contrast material,

drugs, food, the environment, or asthma.

3. Ask the patient if he is claustrophobic, if so, you may want to ask your physician for a

prescription for a mild sedative prior to the scheduled examination.

4. Patients with the following items cannot be scanned: pacemakers, cochlear implants,

metal filings in the eye and cerebral aneurysm clips.

5. Instruct the patient to remove all materials that might be affected or attracted by the

powerful magnet, such as watches, coins, keys, bobby pins, pocket knives and other items.

6. Instruct the patient to lie as still as possible. Moving during the procedure may require

repeating parts of the exam.

4. Cerebral Magnetic Resonance Angiogram (MRA)- This is a noninvasive study which is conducted in a Magnetic Resonance Imager (MRI). The

magnetic images are assembled by a computer to provide an image of the arteries located

in a patients head and neck. The MRA shows the actual blood vessels in the neck and brain

and can help detect blockage and aneurysms.



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1.Explain the procedure to the patient.

2.Instruct the patient to not eat or drink anything after midnight the day before procedure.

3. Prior to the procedure, instruct the patient to put on a hospital gown and remove any

jewelry around head and neck that would interfere with the x-ray beam

4.Ask patient for allergies of any kind, such as allergy to iodine or x-ray contrast material,

drugs, food, the environment, or asthma.

5.Renal function should be evaluated and blood clotting.

6.Prior to the procedure, ask for the patients informed consent.

7.Instruct the patient to lie as still as possible.

5. Carotid duplex (Doppler ultrasound)- In this procedure, ultrasound is used to help detect plaque, blood clots, or other problems

with blood flow in the carotid arteries. There are no known risks and this test is noninvasive

and painless.


1. Explain the procedure to the patient and offer the opportunity to ask any questions that

might have about the procedure.

2. Check for signed consent form that gives permission to do the procedure.

3. Generally, no prior preparation, such as fasting or sedation, is required.4. Ask the patient to refrain from smoking for at least two hours before the test, as

smoking causes blood vessels to constrict and to refrain from consuming caffeine in any

form for about two hours prior to the test.

5. Ask to remove any clothing, jewelry, or other objects that may interfere with the scan.

6. Instruct the patient to lie on an examination table with your neck slightly extended

(bent backward).

6. cerebral angiography- helps determine specific cause of stroke. It pinpoints site of occlusion or rupture. Digital

subtraction angiography evaluates patency of cerebral vessels, identifies their position in

head and neck, and detects/evaluates lesions and vascular abnormalities.Nursing responsibilities:

1. Renal function should be evaluated.

2. The patient should be well hydrated, and clear liquids are usually permitted up to the

time of test.

3. The patient is instructed to void immediately before the test, and locations of the

appropriate peripheral pulses are marked with felt-tip pen.

4. The patient is instructed to remain immobile during the procedure and that there will be

a feeling of warmth and metallic taste prior to the insertion of the contrast agent.

5. A local anesthetic is administered.

6. Perform neurologic assessment during and immediately following cerebral angiography.

7. Observe insertion site for bleeding or hematoma formation.

8. Peripheral pulses that are marked prior to the test are monitored frequently.

9. The color and temperature of the involved extremity are assessed to detect possible

embolism.

7. lumbar puncture (lp)- pressure is usually normal and csf is clear in cerebral thrombosis, embolism, and TIA.

Pressure elevation and grossly bloody fluid suggest subarachnoid and intracerebral

hemorrhage. Csf total protein level may be elevated in cases of thrombosis because of

inflammatory process. Lumbar puncture should be performed if septic embolism from

bacterial endocarditis is suspected.



2. Obtain informed consent.3. Ask the patient to empty his bladder.

4. Position the patient in a lateral recumbent, at the edge of the bed, knees drawn up to

the abdomen, and chin tucked to the chest.

5. Send the CSF specimen immediately.

6. Instruct the patient to lie flat after the procedure to prevent headache.

7. Monitor the patient carefully after the procedure.

8. Give the patient increased fluids at least 24 hours after the procedure.

9. Ensure the comfort of the patient.

8. transcranial doppler ultrasonography- evaluates the velocity of blood flow through major intracranial vessels. It identifies av

disease for example problems with carotid system (blood flow/presence of atheroscleroticplaques).


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2. The patient should be informed that this is not an invasive procedure.

9. Electroencephalogram (EEG)- identifies problems based on reduced electrical activity in specific areas of infarction; and

can differentiate seizure activity from CVA damage.


1. antiseizure agents, tranquilizers, stimulants, and depressants should be withheld 24 to

48 hours before an EEG because these mediactions can alter the results.

2. Coffee, tea, chocolate, and cola drinks are omitted in the meal before the test. However,

the meal is not omitted.

3. The patient is assured that the procedure will not cause him electric shock and that EEG

is for diagnostic exams and not for treatment.

4. Instruct the patient to lie quietly during the procedure.

10.X-RAYS (skull)- may show shift of pineal gland to the opposite side from an expanding mass; calcifications of

the internal carotid may be visible in cerebral thrombosis; partial calcification of walls of an

aneurysm may be noted in subarachnoid hemorrhage.Nursing responsibilities:


2. Patient is not required to restrict food and fluids prior to x-ray.

3. All metal objects like jewelries should be removed prior to procedure.

4. Instruct the patient to remain still during the procedure.

5. Reassure the patient that the procedure will not cause any discomfort.

11. laboratory studies to rule out systemic causes- cbc, platelet and clotting studies,, erythrocyte sedimentation rate (esr), chemistries

(glucose, sodium)

12.ecg, chest x-ray, and echocardiography- to rule out cardiac origin as source of embolus (20% of strokes are the resultof blood or

vegetative emboli associated with valvular disease, dysrhythmias, or endocarditis).

Medical management

1. Identify stroke early

- Proper identification of stroke manifestations and establishing the onset of the

manifestation

2. Maintain cerebral oxygenation

3. Restore cerebral blood flow

a. Thrombolytic agents- are exogenous plasminogen activators which dissolve the thrombus or

embolus blocking the cerebral blood flow

4. Prevent complications

a. Bleeding

Stringent blood pressure management is the single most important measure to prevent

intracranial hemorrhage after thrombolysis.

b. Cerebral edema

All clients are placed on bed rest with the head of the bed elevated to 30 degress to

decrease ICP and to facilitate venous drainage

c. Blood glucose control

d. Stroke recurrence

Heparin- administerd intravenously and is indicated to prevent stroke recurrence in clients

at risk for cardiogenic emboli.

Warfarin- is administered orally after heparin adimistration

Antiplatelet agents- inhibit platelet function to decrease the risk of thrombus formation

e. Aspiration

f. Other potential complication include:

1. Immobility

2. Coma

3. Hyperthermia

4. Blood pressure fluctuations, altered respiratory patterns, and cardiac dysrhythmias


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Rehabilitation after stroke

1. Physical Therapy- To build strength and preserve range of motion (ROM) and tone in non-involved muscles. It

also works on balance and proprioception skills.

2. Occupational Therapy- To relearn activities of daily living (ADL) and to use assistive devices that proote

independence

3. Speech Therapy- To foster the maximum amount of speech recovery possible

NURSING MANAGEMENT

1. Assessment of neurologic status, blood pressure, heart sounds, heart rate and rhythm,

respiratory rate and rhythm, temperature, levels of nutrition, ability to swallow, bladder and

bowel elimination, and communication.

2. Maintain the clients blood pressure within the range prescribed by the physician to maintain

perfusion without promoting cerebral edema.

3. Maintain normothermia to reduce cerebral glucose and oxygen consumption.

4. Elevate the head of the bed 30 degrees to reduce cerebral edema.

5. Assess the client for clinical manifestations of aspiration, such as fever, dyspnea, crackles and

rhonchi, confusion, and decreased Pao2 in arterial blood gas.

6. Monitor chest x-ray results, and report findings of pulmonary infiltrate.

7. Assess the clients degree of muscle strength to use as a baseline value and for determining

and evaluating outcomes.

8. Frequent gluteal and quadriceps muscle setting exercises during the day help to prepare the

client for later ambulation.

9. Treat the fever with antipyretics. A hypothermic blanket may be used.

10.Assess the skin every 2 hours. Turn the client with hemiplegia or decreased LOC every 2 hours.

11.Passive ROM exercises two times daily after the first 24 hours following a stroke unless

otherwise prescribed. Active ROM to the unaffected extremities in maintaining or increasing

muscle strength

12.Encourage the patient to perform as many self-care activities as possible.

13.Provide mouth care at least 3 or 4 times a day.

14.Keep the side rails of the bed raised for clients with recent hemiplegia to prevent them form

rolling out of bed.

15.Give supplemental meals as necessary.

16.Speech therapy should be started early.

17.Goals Include:

o To keep patient alive and maintain vital functions

o To minimize further cerebral damage

18.Maintain patient airway

19.Monitor urinary function and observe fluid restrictions

20.Seizure precautions

21.Pharmacotherapy:

a. Diuretics Anticoagulants Antihypertensives

b. Antiplatelets Anticonvulsants Vasopressors

22.Emotional Support and Calm environment

Surgical prevention for Ischemic Stroke

1. Carotid endarterectomy

-is the removal of an atherosclerotic plaque or thrombus from the carotid artery to prevent

stroke in patients with occlusive disease of the extracranial cerebral arteries

-indicated for patients with symptoms of TIA or mild stroke to be caused by severe carotid

artery stenosis or moderate stenosis with other significant risk factors

Nursing management:

a. Maintain adequate blood pressure levels in the immediate postoperative period.


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b. Hypotension is avoided to prevent cerebral ischemia and thrombosis.

c. Close cardiac monitoring is necessary, because these patients have a high incidence of

coronary artery disease.

d. Monitor and document assessment parameters fro all body systems, with particular

attention to neurologic status.

e. Focus on assessment of the following cranial nerves: facial (VII), vagus (X), spinal

accessory (XI), and hypoglossal (XII)

f. Emergency airway supplies, including those needed for tracheostomy, must be

available

2. Carotid stenting (with or without angioplasty)

- is a less invasive procedure that is used, at times, for severe stenosis

- A large metal coil (stent) is placed in the carotid artery much like a stent is placed in a coronary

artery. The femoral artery is used as the site for passage of a special hollow tube to the area of

blockage in the carotid artery. This procedure is often done in radiology labs, but may be

performed in the cath lab.

- it is used for selected patients who are at high risk for surgery and its efficacy continues to be

investigated

3. Craniotomy- a type of surgery in the brain itself to remove blood clots.

Surgical management for Hemorrhagic stroke

1. Surgical evacuation via craniotomy

- is done if the diameter of the hematoma exceeds 3cm and the Glasgow coma scale score

decreases

2. Surgery to repair aneurysms and arteriovenous malformations (AVMs)

-An aneurysm is a weakened, ballooned area on an artery wall that has a risk for rupturing and

bleeding into the brain. An AVM is a congenital (present at birth) or acquired disorder that

consists of a disorderly, tangled web of arteries and veins. An AVM also has a risk for rupturingand bleeding into the brain. Surgery may be helpful, in this case, to help prevent a stroke from

occurring.

a. Endovascular treatment (occlusion of the parent artery)

- for aneurysms

b. Aneurysm coiling (obstruction of the aneurysm site with a coil)

Primary prevention of stroke:

1. Maintaining an ideal body weight

2. Maintaining safe cholesterol levels

3. Smoking cessation

4. Using low-dose estrogen contraceptives only in the absence of other risk factors

5. Reducing heavy alcohol consumption

6. Eliminating illicit drug use

Secondary prevention:

1. Adequate blood pressure control

2. Care of Diabetes mellitus

3. Treatment of cardiovascular diseases, TIA, and atrial fibrillation

Introduction Cva 8

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