Transcript Management of Patients with Cerebrovascular Disorders

Management of Patients with
Cerebrovascular Disorders
Chapter 62
Page 1896
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LEARNING OBJECTIVES
• On completion of this chapter, the learner will be able to:
1- Describe the incidence and social impact of cerebrovascular
disorders.
2- Identify the risk factors for cerebrovascular disorders and
related measures for prevention.
3- Compare the various types of cerebrovascular disorders: their
causes, clinical manifestations, and medical management.
4- Apply the principles of nursing management to the care of a
patient in the acute stage of an ischemic stroke.
5- Use the nursing process as a framework for care of a patient
recovering from an ischemic stroke.
6- Use the nursing process as a framework for care of a patient
with a hemorrhagic stroke.
7- Identify essential elements for family teaching and preparation
for home care of the patient who has had a stroke.
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Introduction
• Cerebrovascular disorders is an umbrella term that refers
to a functional abnormality of the central nervous system
(CNS) that occurs when the normal blood supply to the
brain is disrupted.
• Stroke is the primary cerebrovascular disorder and it is the
third leading cause of death after heart disease and cancer.
• Strokes can be divided into two major categories:
1- Ischemic (85%), in which vascular occlusion and significant
hypoperfusion occur.
2- hemorrhagic (15%), in which there is extravasation of blood
into the brain or subarachnoid space (Hinkle & Guanci, 2007).
• Although there are some similarities between the two
broad types of stroke, differences exist in etiology,
pathophysiology, medical management, surgical
management, and nursing care.
• Table 62-1 compares ischemic and hemorrhagic strokes
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Ischemic stroke
• An ischemic stroke, cerebrovascular accident
(CVA), or “brain attack” is a sudden loss of
function resulting from disruption of the
blood supply to a part of the brain.
• Thrombus formation and occlusion at the site
of the atherosclerosis result in ischemia and
infarction (deprivation of blood supply
(Hinkle & Guanci, 2007).
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Clinical Manifestations
• An ischemic stroke can cause a wide variety of neurologic deficits,
depending on :
- the location of the lesion (which vessels are obstructed).
- The size of the area of inadequate perfusion.
- The amount of collateral (secondary or accessory) blood flow
The patient may present with any of the following signs or symptoms:
• 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, or loss of balance or coordination
• Sudden severe headache
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Motor Loss
• A stroke is an upper motor neuron lesion and results in loss of
voluntary control over motor movements.
• Because the upper motor neurons decussate (cross), a disturbance
of voluntary motor control on one side of the body may reflect
damage to the upper motor neurons on the opposite side of the
brain.
• The most common motor dysfunction is hemiplegia (paralysis of
one side of the body) caused by a lesion of the opposite side of the
brain.
• Hemiparesis, or weakness of one side of the body, is another sign.
• In the early stage of stroke, the initial clinical features may be
flaccid paralysis and loss of or decrease in the deep tendon
reflexes.
• When these deep reflexes reappear (usually by 48 hours), increased
tone is observed along with spasticity (abnormal increase in muscle
tone) of the extremities on the affected side.
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Communication Loss
• Other brain functions affected by stroke are language and
communication.
• stroke is the most common cause of aphasia.
• The following are dysfunctions of language and
communication.
• Dysarthria (difficulty in speaking), caused by paralysis of the
muscles responsible for producing speech
• Dysphasia (impaired speech) or aphasia (loss of speech),
which can be expressive aphasia, receptive aphasia, or global
(mixed) aphasia
• Apraxia (inability to perform a previously learned action), as
may be seen when a patient makes verbal substitutions for
desired syllables or words.
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Perceptual Disturbances
• Perception is the ability to interpret sensation.
• Stroke can result in visual-perceptual dysfunctions,
disturbances in visual- spatial relations, and sensory loss.
• Visual-perceptual dysfunctions are caused by
disturbances of the primary sensory pathways between
the eye and visual cortex.
• Homonymous hemianopsia (loss of half of the visual
field) may occur from stroke and may be temporary or
permanent.
• The affected side of vision corresponds to the paralyzed
side of the body.
• Disturbances in visual-spatial relations (perceiving the
relationship of two or more objects in spatial areas) are
frequently seen in patients with right hemispheric
damage.
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Sensory Loss
• The sensory losses from stroke may take the
form of slight impairment of touch, or it may
be more severe, with loss of proprioception
(ability to perceive the position and motion of
body parts) as well as difficulty in interpreting
visual, tactile, and auditory stimuli.
• Agnosias are deficits in the ability to recognize
previously familiar objects perceived by one or
more of the senses.
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Cognitive Impairment and Psychological Effects
• If damage has occurred to the frontal lobe, learning
capacity, memory, or other higher cortical intellectual
functions may be impaired.
• Such dysfunction may be reflected in a limited attention
span, difficulties in comprehension, forgetfulness, and a
lack of motivation.
• These changes can cause the patient to become easily
frustrated during rehabilitation.
• Depression is common and may be exaggerated by the
patient’s natural response to this catastrophic event.
• Emotional lability, hostility, frustration, resentment, lack of
cooperation, and other psychological problems may occur.
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Assessment and Diagnostic Findings
• Any patient with neurologic deficits needs a careful history and a
complete physical and neurologic examination.
• Initial assessment focuses on airway patency, which may be
compromised by loss of gag or cough reflexes and altered respiratory
pattern; cardiovascular status (including blood pressure, cardiac
rhythm and rate, carotid bruit); and gross neurologic deficits.
• The initial diagnostic test for a stroke is usually a noncontrast
computed tomography (CT) scan performed emergently to determine
if the event is ischemic or hemorrhagic .
• A 12-lead electrocardiogram (ECG) and a carotid ultrasound are
standard tests.
• Other studies may include CT angiography or magnetic resonance
imaging and angiography (MRI and MRA) of the brain and neck vessels;
transcranial Doppler flow studies; transthoracic or transesophageal
echocardiography; xenon-enhanced CT scan; and single photon emissio
CT (SPECT) scan (Adams, Zoppo, Alberts, et al., 2007).
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Prevention
• healthy lifestyle, which includes not smoking,
maintaining a healthy weight following a healthy
diet (including modest alcohol consumption), and
daily exercise, can reduce the risk of having a stroke
by about one half.
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Preventive Treatment and Secondary
Prevention
• Health maintenance measures including a healthy
diet, exercise, and the prevention and treatment
of periodontal disease
• Carotid endarterectomy
• Anticoagulant therapy
• Antiplatelet therapy: aspirin, dipyridamole
(Persantine), clopidogrel (Plavix), ticlopidine
(Ticlid)
• “Statins”
• Antihypertensive medications
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Medical Management
Thrombolytic Therapy
• Thrombolytic agents are used to treat ischemic stroke by
dissolving the blood clot that is blocking blood flow to the
brain.
• It works by binding to fibrin and converting plasminogen to
plasmin, which stimulates fibrinolysis of the atherosclerotic
lesion
• Rapid diagnosis of stroke and initiation of thrombolytic
therapy (within 3 hours) in patients with ischemic stroke leads
to a decrease in the size of the stroke and an overall
improvement in functional outcome after 3 months (Adams, et
al., 2007; NINDS, 1995).
• The dosage for t-PA is 0.9 mg/kg, with a maximum dose of 90
mg. Ten percent of the calculated dose is administered as an
intravenous (IV) bolus over 1 minute. The remaining dose (90%)
is administered IV over 1 hour via an infusion pump.
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NURSING PROCESS
THE PATIENT RECOVERING FROM
AN
ISCHEMIC STROKE
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Assessment
• Change in level of consciousness or responsiveness as evidenced by
movement, resistance to changes of position, and response to stimulation;
orientation to time, place, and person
• Presence or absence of voluntary or involuntary movements of the
extremities; muscle tone; body posture; and position of the head.
• Stiffness or flaccidity of the neck
• Eye opening, comparative size of pupils and pupillary reactions to light,
and ocular position
• Color of the face and extremities; temperature and moisture of the skin
• Quality and rates of pulse and respiration; arterial blood gas values as
indicated, body temperature, and arterial pressure
• Ability to speak
• Volume of fluids ingested or administered; volume of urine excreted each
24 hours
• Presence of bleeding
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Assessment
• Maintenance of blood pressure within the desired
parameters
• After the acute phase, the nurse assesses mental status
(memory, attention span, perception, orientation, affect,
speech/language), sensation/perception.
• usually the patient has decreased awareness of pain and
temperature), motor control (upper and lower extremity
movement), swallowing ability, nutritional and hydration
status, skin integrity, activity tolerance, and bowel and
bladder function.
• Ongoing nursing assessment continues to focus on any
impairment of function in the patient’s daily activities,
because the quality of life after stroke is closely related to
the patient’s functional status.
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Nursing Diagnoses
Based on the assessment data, the major nursing diagnoses for a patient with a
stroke may include the following:
• Impaired physical mobility related to hemiparesis, loss of balance and
coordination, spasticity, and brain injury
• Acute pain (painful shoulder) related to hemiplegia and disuse
• Self-care deficits (bathing, hygiene, toileting, dressing, grooming, and feeding)
related to stroke sequelae
• Disturbed sensory perception (kinesthetic, tactile or visual) related to altered
sensory reception, transmission, and/or integration
• Impaired swallowing
• Impaired urinary elimination related to flaccid bladder, detrusor instability,
confusion, or difficulty in communicating
• Disturbed thought processes related to brain damage
• Impaired verbal communication related to brain damage
• Risk for impaired skin integrity related to hemiparesis hemiplegia, or decreased
mobility
• Interrupted family processes related to catastrophic illness and caregiving
burdens
• Sexual dysfunction related to neurologic deficits or fear of failure
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Nursing Interventions
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•
•
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Improving Mobility and Preventing Joint Deformities
Enhancing Self-Care
Managing Sensory-Perceptual Difficulties
Assisting With Nutrition
Attaining Bowel and Bladder Control
Improving Thought Processes
Improving Communication
Maintaining Skin Integrity
Improving Family Coping
Promoting Home and Community-Based Care
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Hemorrhagic Stroke
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Hemorrhagic Stroke
• Hemorrhagic strokes account for 15% to 20% of
cerebrovascular disorders and are primarily caused by
intracranial or subarachnoid hemorrhage.
• Hemorrhagic strokes are caused by bleeding into the
brain tissue, the ventricles, or the subarachnoid space.
• Primary intracerebral hemorrhage from a spontaneous
rupture of small vessels accounts for approximately
80% of hemorrhagic strokes and is caused chiefly by
uncontrolled hypertension.
• Subarachnoid hemorrhage results from a ruptured
intracranial aneurysm (a weakening in the arterial wall)
in about half the cases (Hickey, 2009).
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Intracerebral Hemorrhage
• An intracerebral hemorrhage, or bleeding into the brain
tissue, is most common in patients with hypertension and
cerebral atherosclerosis, because degenerative changes
from these diseases cause rupture of the blood vessel.
• An intracerebral hemorrhage may also result from certain
types of arterial pathology, brain tumors, and the use of
medications (eg, oral anticoagulants, amphetamines, and
illicit drug use). Bleeding occurs most commonly in the
cerebral lobes, basal ganglia, thalamus, brain stem (mostly
the pons), and cerebellum (Hickey, 2009).
• Occasionally, the bleeding ruptures the wall of the lateral
ventricle and causes intraventricular hemorrhage, which is
frequently fatal.
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Intracranial (Cerebral) Aneurysm
• An intracranial (cerebral) aneurysm is a dilation of the walls of a
cerebral artery that develops as a result of weakness in the arterial
wall.
• The cause of aneurysms is unknown, although research is ongoing.
• An aneurysm may be due to atherosclerosis, which results in a defect
in the vessel wall with subsequent weakness of the wall; a congenital
defect of the vessel wall; hypertensive vascular disease; head trauma;
or advancing age.
• Any artery within the brain can be the site of a cerebral aneurysm, but
these lesions usually occur at the bifurcations of the large arteries at
the circle of Willis (Fig. 62-5).
• The cerebral arteries most commonly affected by an aneurysm are the
internal carotid artery (ICA), anterior cerebral artery (ACA), anterior
communicating artery (ACoA), posterior communicating artery
(PCoA), posterior cerebral artery (PCA), and middle cerebral artery
(MCA).
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Arteriovenous Malformations
• Most AVMs are caused by an abnormality in
embryonal development that leads to a tangle
of arteries and veins in the brain that lacks a
capillary bed (see Fig. 62-5).
• The absence of a capillary bed leads to
dilation of the arteries and veins and eventual
rupture.
• AVM is a common cause of hemorrhagic
stroke in young people.
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Subarachnoid Hemorrhage
• A subarachnoid hemorrhage (hemorrhage into
the subarachnoid space) may occur as a result
of an AVM, intracranial aneurysm, trauma, or
hypertension.
• The most common causes are a leaking
aneurysm in the area of the circle of Willis and
a congenital AVM of the brain.
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Clinical Manifestations
• Table 62-2 reviews the neurologic deficits frequently
seen in stroke patients.
• Table 62-3 compares the symptoms seen in right
hemispheric stroke with those seen in left hemispheric
stroke.
• Other symptoms that may be observed more
frequently in patients with acute intracerebral
hemorrhage (compared with ischemic stroke) are :
– vomiting, an early sudden change in level of
consciousness, and possibly focal seizures due to frequent
brain stem involvement (Hickey, 2009).
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Clinical Manifestations
• sudden, unusually severe headache and often loss of
consciousness for a variable period of time.
• There may be pain and rigidity of the back of the neck
(nuchal rigidity) and spine due to meningeal irritation.
• Visual disturbances (visual loss, diplopia, ptosis) occur
if the aneurysm is adjacent to the oculomotor nerve.
• Tinnitus, dizziness, and hemiparesis may also occur.
• At times, an aneurysm or AVM leaks blood, leading to
the formation of a clot that seals the site of rupture.
• severe bleeding occurs, resulting in cerebral damage,
followed rapidly by coma and death.
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Assessment and Diagnostic Findings
• Any patient with suspected stroke should undergo a CT
scan or MRI to determine the :
• type of stroke, the size and location of the hematoma,
and the presence or absence of ventricular blood and
hydrocephalus.
• Cerebral angiography confirms the diagnosis of an
intracranial aneurysm or AVM.
• These tests show the location and size of the lesion and
provide information about the affected arteries, veins,
adjoining vessels, and vascular branches.
• Lumbar puncture is performed if there is no evidence
of increased ICP.
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Prevention
• managing hypertension and ameliorating other
significant risk factors.
• Control of hypertension, especially in people older
than 55 years of age, reduces the risk of
hemorrhagic stroke (Luders, 2007).
• Additional risk factors are increased age, male
gender, and excessive alcohol intake.
• Stroke risk screenings provide an ideal opportunity
to lower hemorrhagic stroke risk by identifying high
risk individuals or groups and educating patients and
the community about recognition and prevention.
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complications
•
•
•
•
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Cerebral Hypoxia and Decreased Blood Flow
Vasospasm
Increased Intracranial Pressure
Hypertension
Medical Management
• The goals of medical treatment for
hemorrhagic stroke are to allow the brain to
recover from the initial insult (bleeding), to
prevent or minimize the risk of rebleeding,
and to prevent or treat complications.
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Medical Management
• bed rest with sedation to prevent agitation and stress,
• Management of vasospasm, and surgical or medical treatment to
prevent rebleeding.
• If the bleeding is caused by anticoagulation with warfarin
(Coumadin), the INR may be corrected with fresh-frozen plasma
and vitamin K.
• Antiseizure agents are often administered prophylactically for a
brief period of time.
• Analgesic agents may be prescribed for head and neck pain.
• The patient is fitted with sequential compression devices or antiembolis stockings to prevent deep vein thrombosis (DVT).
• Fever should be treated.
• Hyperglycemia should also be treated (an IV insulin drip may be
required to achieve control)
• After discharge most patients will require antihypertensive
medications to decrease their risk of another intracerebral
hemorrhage.
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Surgical Management
• if the diameter of the hematoma exceeds 3
cm and the Glasgow Coma Scale score
decreases, surgical evacuation is strongly
recommended for the patient with a
cerebellar hemorrhage (Broderick, et al.,
2007).
• Surgical evacuation is most frequently
accomplished via a craniotomy.
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NURSING PROCESS
THE PATIENT WITH
A HEMORRHAGIC
STROKE
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Assessment
• A complete neurologic assessment is performed initially and
includes evaluation for the following:
• Altered level of consciousness
• Sluggish pupillary reaction
• Motor and sensory dysfunction
• Cranial nerve deficits (extraocular eye movements, facial droop,
presence of ptosis)
• Speech difficulties and visual disturbance
• Headache and nuchal rigidity or other neurologic deficits
• Any changes in the patient’s condition require reassessment and
thorough documentation; changes should be reported immediately.
• Alteration in level of consciousness often is the earliest sign of
deterioration in a patient with a hemorrhagic stroke.
• Because nurses have the most frequent contact with patients, they are
in the best position to detect subtle changes.
• Mild drowsiness and slight slurring of speech may be early signs that
the level of consciousness is deteriorating.
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Nursing Diagnoses
• Based on the assessment data, the patient’s
major nursing diagnoses may include the
following:
• Ineffective tissue perfusion (cerebral) related
to bleeding or vasospasm
• Disturbed sensory perception related to
medically imposed restrictions (aneurysm
precautions)
• Anxiety related to illness and/or medically
imposed restrictions (aneurysm precautions)
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Planning and Goals
• The goals for the patient may include
improved cerebral tissue perfusion
• relief of sensory and perceptual deprivation,
• relief of anxiety, and the absence of
complications.
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Nursing Interventions
• Optimizing Cerebral Tissue Perfusion
• Relieving Sensory Deprivation and Anxiety
• Monitoring and Managing Potential
Complications
• Promoting Home and Community-Based Care
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CRITICAL THINKING EXERCISES
• A patient had symptoms of an ischemic
stroke approximately 1 hour ago and is
undergoing a CT scan.
• What are the time frames, criteria, and dosage
for t-PA administration?
• What nursing assessments and actions would
you take?
• What is your rationale for these assessments
and actions?
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