Management of Patients with Cerebrovascular Disorders: Stroke Flashcards
Cerebrovascular Disorders
- Functional abnormality of the CNS that occurs when the blood supply to the brain is disrupted
- Stroke is the primary cerebrovascular disorder and the fifth leading cause of death in the United States
- Stroke is the leading cause of serious long-term disability in the United States
- Financial impact is profound
Brain Attack
National Stroke Association uses this term for a better description to convey the message of medical emergency as brain cells are dying.
Stroke
- Brain attack
- Sudden loss of function resulting from a disruption of the blood supply to a part of the brain
- Types of stroke: refer to table 67-1(pg 2010)
— Hemorrhagic (13%)
— Ischemic (87%)
General Pathophysiology of Strokes
- Disruption of blood flow
- Na-K pumps begins to fail
- Cells die
- Causes varying degrees of disabilities
Left hemispheric stroke:
- Paralysis or weakness on right side of body
- Right visual field deficit
- Aphasia (expressive, receptive, or global)
- Altered, intellectual ability
- Slow, cautious behavior
Right hemispheric stroke:
- Paralysis or weakness on the left side of body
- Left visual field deficit
- Spatial- perceptual deficits
- Increased distractibility
- Impulsive behavior and poor judgment
- Lack of awareness of deficits
Ischemic Stroke
- Disruption of the blood supply caused by an obstruction, usually a thrombus or embolism, related to hypertension and diabetes, that causes infarction of brain tissue.
- Often preceded by a transient, ischemic attack
- Embolic – a thrombus (afib?) from heart or elsewhere travels to cerebral vessel and lodges with rapid progression
- Penumbra region is the area around the area of infarction. This brain tissue may be salvaged as it is ischemic with timely intervention to stop the ischemic cascade. The interventions are limiting the extent of secondary brain injury; example: tissue plasminogen activator (t-PA).
Ischemic Stroke
Causes/Types
- Large artery thrombosis
- Small penetrating artery thrombosis
- Cardiogenic embolism
- Cryptogenic (no known cause)
- Other
Ischemia
- Thrombus – Thrombotic Stroke
- Most common; 50 % of all strokes
- Caused by a clot
- Embolus – Embolic stroke
Manifestations of Ischemic Stroke
- Dependent on the location of the lesion, size of the area of inadequate perfusion, and the amount of collateral blood flow.
- Numbness or weakness of face, arm, or leg, especially on one side
- Hemiplegia
- Hemiparesis
- Hemianopsia
- Apraxia
- Aphasia
- Agnosia
- Diplopia
- Dysarthria
- Loss of peripheral vision
- Confusion or change in mental status
- Difficulty in walking, dizziness, or loss of balance or coordination
- Sudden, severe headache (MORE SO HEMERAGIC STROKE)
- Perceptual disturbances
Hemiplegia
paralysis on one side of the body.
Hemiparesis
weakness of one side, or part of it
Apraxia
is the inability to perform a previously learned action
Dysarthria
difficulty speaking or dysphasia- impaired speaking
& Swallowing
Aphasia
expressive: inability to express oneself, receptive: is the inability to understand language
- expressive aphasia- Broca’s area
- receptive aphasia – Wernicke’s area
Hemianopsia
loss of half of the visual field; pts neglect one side of the body/ difficulty judging distance
Agnosia
the loss of the ability to recognize objects through a particular sensory system; it may be visual, auditory or tactile
Diplopia
double vision
Ischemic Stroke Functional recovery:
usually plateaus at 6 months
Ischemic Stroke Prevention
- Refer to Chart 67-2
- Nonmodifiable risk factors
— Age (older than 55 years), male gender, African Americans - Modifiable risk factors
— Hypertension is the primary risk factor
— Cardiovascular disease
— Elevated cholesterol or elevated hematocrit
— Obesity
— Diabetes - Oral contraceptive use
Transient Ischemic Attack (TIA)
- Temporary neurologic deficit resulting from a temporary impairment of blood flow, typically lasting 1 to 2 hours.
- Manifested by a sudden loss of motor, sensory or visual function.
- “Warning of an impending stroke”
- Diagnostic workup is required to treat and prevent irreversible deficits
Ischemic Stroke Medical Management
DX:
- Prevention: control of hypertension
- Diagnosis:
— cerebral angiography
— CT scan
—- 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 vasospasm, increased ICP, hypertension, potential seizures, and prevention of further bleeding
Ischemic Stroke Preventive Treatment and Secondary Prevention
- Health maintenance measures including a healthy lifestyle, not smoking, exercise, healthy diet and weight
- Carotid endarterectomy for carotid stenosis
- Anticoagulant therapy for atrial fibrillation
- Antiplatelet therapy
- “Statins”
- Antihypertensive medications
Carotid Endarterectomy
Common in carotid stenosis
An older patient is admitted to the critical care unit after a left carotid endarterectomy this morning. Which nursing assessment finding is the most important to report to the surgeon?
A. Nausea when moving in bed
B. Blood pressure of 148/86 mm Hg
C. Pain rated at 5 on a 1-10 scale
D. Increased drowsiness
D. (Decrease LOC)
Medical Management: Acute Phase of Stroke
- Prompt diagnosis and treatment: refer to Table 67-4
- Assessment of stroke: NIHSS assessment tool
- Thrombolytic therapy
— Criteria for tPA: refer to Chart 67-3
— IV dosage and administration
— Patient monitoring
— Side effects: potential bleeding - Elevate head of bed (HOB) unless contraindicated
- Maintain airway and ventilation
- Continuous hemodynamic monitoring and neurologic assessment