9.9 Cerebrovascular Accident

A cerebrovascular accident (CVA), commonly referred to as a stroke, is a sudden interruption of blood flow to the brain that requires immediate emergency care. A spectrum of neurological deficits and potential complications can occur as a result of a CVA. Each year in the United States, there are more than 800,000 strokes. Stroke is a leading cause of death or serious long-term disability. Nearly three quarters of all strokes occur in people over the age of 65.

Diagnosing and treating a stroke is often referred to as “time is brain.” With timely treatment, it is possible to save brain cells and greatly reduce the damage or death that can occur due to a stroke. Brain cells die because they stop getting the oxygen and nutrients needed to function, or they are damaged by sudden bleeding in or around the brain. Knowing the signs of stroke and calling 911 immediately can help save someone’s life.^[1]

Pathophysiology

There are two types of strokes called ischemic and hemorrhagic. An acute ischemic stroke is caused by a blockage or occlusion of a cerebral or carotid artery. This can be caused by plaque that has built up within the vessel, resulting in a thrombus or a blood clot that has traveled from another area of the body and lodged in the blood vessel, referred to as an embolism. An ischemic stroke is further categorized depending on the cause. CVAs caused by a thrombus are referred to as a thrombotic stroke, and CVAs caused by an embolism are called an embolic stroke. Thrombotic strokes account for more than half of all strokes and commonly occur because of atherosclerosis. An embolic stroke is caused by a thrombus or a group of thrombi that break away from one area of the body and travel through the arterial system via the carotid artery or through the arteries at the base of the skull. The most common source of the emboli is the heart. For example, emboli occur frequently in clients with atrial fibrillation, where tiny clots form within the atria of the heart and then break away and move into the brain’s circulation.

The second type of CVA is a hemorrhagic stroke. With this type of stroke, the stability of a blood vessel in the brain is compromised, leading to rupture and bleeding. The blood accumulates into the brain tissue or subarachnoid space. As the blood presses against the tissue in the brain, it can increase intracranial pressure.^[2]

Several factors can lead to a hemorrhagic stroke. Sustained elevated blood pressure can cause changes within the arterial wall, making it susceptible to rupture. If this occurs it can cause an intracerebral hemorrhage, leading to bleeding, which causes edema irritation and displacement of the brain tissue. A subarachnoid hemorrhage is more common and refers to bleeding in the space between the brain and the surrounding membrane (subarachnoid space). This bleeding is usually triggered by a ruptured aneurysm or arteriovenous malformation. An aneurysm is an abnormal bulging or ballooning that develops in a weak spot of the arterial wall, which may become so thin that it ruptures. The primary symptom is a sudden, severe headache, often described by clients as the worst headache they have ever felt.^[3]

An arteriovenous malformation is a tangle of blood vessels that irregularly connects arteries and veins that can rupture, causing bleeding in the brain and spinal cord. See Figure 9.23^[4] for an illustration comparing ischemic and hemorrhagic strokes and Figure 9.24^[5] for an image containing a radiographic image of a hemorrhagic stroke.

Transient ischemic attacks (TIAs) are temporary periods of symptoms similar to a stroke, but irreversible damage to the brain cells do not occur. However, TIAs are considered warning signs of an impending stroke. With prompt diagnosis and treatment of TIAs, a CVA can be prevented.^[6]

See Table 9.9 for a comparison of types of CVAs.

Table 9.9. Comparison of Types of CVAs

Assessment

If an evolving CVA is suspected, a rapid assessment is performed with rapid transport to a stroke center designated by The Joint Commission or other accredited organization for rapid treatment. If a client is already hospitalized for another medical condition, many hospitals have designated stroke teams and protocols that are immediately implemented.

The National Institutes of Health Stroke Scale (NIHSS) is a standardized tool that is commonly used to assess clients suspected of experiencing an acute cerebrovascular accident (i.e., stroke).^[7] It is also used to quantify the severity of a stroke by assigning numbers to the symptoms, with higher numbers indicating more dysfunction. The three most predictive findings that occur during an acute stroke are facial drooping, arm drift/weakness, and abnormal speech. Use the box below to view the NIH stroke scale.

A commonly used mnemonic regarding assessment of individuals suspected of experiencing a stroke is “BEFAST.” BEFAST stands for Balance, Eyes, Face, Arm, Speech, and Time.

• B: Does the person have a sudden loss of balance?
• E: Has the person lost vision in one or both eyes?
• F: Does the person’s face look uneven?
• A: Is one arm weak or numb?
• S: Is the person’s speech slurred? Are they having trouble speaking or seem confused?
• T: Time to call for assistance immediately

Clients experiencing a hemorrhagic CVA often report “having the worst headache of my life” with sudden onset and no known cause. Other signs of hemorrhage may include nausea, vomiting, photophobia, and a stiff neck. Other common stroke symptoms are as follows:

• Sudden numbness or weakness of an arm or leg, especially on one side of the body
• Sudden confusion, trouble speaking, or understanding
• Sudden loss of vision or trouble seeing in one or both eyes
• Sudden trouble walking, dizziness, or loss of balance or coordination

During the initial client presentation, nurses observe the client’s level of consciousness (LOC) and administer the Glasgow Coma Scale. Review information about the Glasgow Coma Scale in the “General Assessment of the Nervous System” section.

Depending on the extent and location of the CVA, specific chronic signs and symptoms may occur. For instance, if a CVA occurs in the right cerebral hemisphere, visual and spatial awareness are affected, as well as possible personality changes, impulsivity, and poor judgment. Clients with left hemisphere involvement may have problems with speech, language, and analytic thinking. See the following box for other complications that can occur as a result of a CVA.

Common Laboratory and Diagnostic Tests

A CT scan without contrast is typically the first diagnostic test performed for clients with a suspected CVA to determine if a hemorrhagic stroke is occurring.^[10] If a hemorrhagic stroke is ruled out with a CT scan, tests are performed to identify potential causes of an ischemic stroke. For example, a carotid duplex/doppler ultrasound may be performed on the carotid arteries to assess for occlusion. A cardiac echocardiogram may be performed to assess for clots caused by atrial fibrillation. An MRI may be performed to assess for brain lesions. A cerebral angiogram may be performed to determine the blockage site.^[11]

Blood tests such as prothrombin time (PT), international normalized ratio (INR), and activated partial thromboplastin time (aPTT) are performed to provide baseline information if fibrinolytic or anticoagulation therapy for an ischemic stroke is initiated. Review normal reference ranges for common diagnostic tests in “Appendix A – Normal Reference Ranges.”

Nursing Diagnoses

Depending on the severity of the stroke and the reason for immediate treatment, airway, breathing, and circulation take priority. Common nursing diagnoses include the following^[12]:

• Risk for Inadequate Cerebral Tissue Perfusion
• Decreased Physical Mobility
• Impaired Verbal Communication
• Impaired Swallowing
• Unilateral Neglect
• Ineffective Coping
• Feeding, Bathing, or Dressing Self-care Deficit

Outcome Identification

After a client experiences a CVA, rehabilitation continues throughout the convalescent period, relying on a collaborative effort of a multidisciplinary team including nurses, physical therapists, occupational therapists, and speech therapists, as well as case managers. Overall goals include the following:

• Improved mobility
• Achievement or improvement in self-care
• Relief of sensory and perceptual deprivation
• Prevention of aspiration
• Bowel and bladder continence
• Improved thought processes
• Optimization of communication
• Maintenance of skin integrity
• Absence of complications or injury

Sample outcome criteria include the following:

• The client will maintain intact skin integrity during hospitalization despite impaired mobility.
• The client will not aspirate food, fluids, or medications during hospitalization.
• The client will not fall during hospitalization.
• The client will demonstrate accurate use of assistive devices after the teaching session.

Interventions

Medical Interventions

Hemorrhagic Stroke

The most common cause of hemorrhagic stroke is hypertension. Blood pressure is reduced gradually to 150/90 mmHg using a beta-blocker, ACE inhibitor, calcium channel blocker, or hydralazine. The role of surgery in hemorrhagic stroke is a controversial topic. Current research indicates emergency surgery for cerebellar hemorrhage greater than 3 cm in diameter, hydrocephalus (fluid accumulation in the brain), or brain stem compression. Minimally invasive procedures are also being investigated.^[13]

Ischemic Stroke

Medical treatments for clients with acute ischemic stroke include IV fibrinolytic therapy and endovascular interventions.

Medication Therapy

IV fibrinolytic therapy, also known as “clot-buster medication,” is administered for specific clients experiencing an ischemic stroke who meet selective criteria. It is standard of practice to improve blood flow to the viable brain tissue around the infarction. IV alteplase is the only FDA-approved medication for acute ischemic stroke. Treatment is dependent on the timing of symptom onset and treatment initiation. The FDA recommends administration of IV alteplase within three hours of stroke onset and up to 4.5 hours in some cases. However, alteplase is not administered for clients with the following contraindications^[14]:

• Age over 80 years
• Use of anticoagulants
• History of stroke and diabetes

Ongoing drug therapy depends on the type and severity of the stroke and the neurologic dysfunction. The general purpose of ongoing drug therapy is to prevent further thrombotic or embolic episodes by prescribing antithrombotics and anticoagulants and to protect the neurons from hypoxia. An initial low dose of aspirin is recommended 24 to 48 hours after the onset of stroke, but it should not be administered within 24 hours after alteplase. A calcium channel blocker such as nimodipine may be prescribed to treat vertebral vasospasm after a subarachnoid hemorrhage. Stool softeners, antianxiety medications, and analgesics may also be prescribed for symptom management. Blood pressure medications may also be prescribed to treat underlying hypertension.

Surgical Management

Endovascular procedures may be performed for clients experiencing an ischemic stroke. The procedure improves perfusion by surgically removing the thrombus from the affected artery.

If a client is experiencing a hemorrhagic stroke caused by a cerebral aneurysm or an arteriovenous malformation (AVM), a procedure is performed by a neurosurgeon to stop the bleeding. Clients experiencing a hemorrhagic stroke are at risk for developing increased intracranial pressure (ICP) within the first 72 hours after onset due to edema within the brain.

See the following box for signs and symptoms of increased ICP.

Nursing Interventions

During the acute treatment of a stroke, nursing interventions focus on maintaining physiological integrity and reducing the risk of complications. Nursing interventions during the acute phase of a stroke are provided in the following box.

If a client is experiencing increased ICP following a hemorrhagic stroke, nurses implement interventions to manage ICP. See related nursing interventions in the following box.

Health Teaching and Promotion

Following care of an acute stroke, health teaching focuses on reducing modifiable risk factors for another stroke and improving long-term functioning. Prevention strategies include quitting smoking, controlling blood pressure, managing glucose levels within the healthy range, making healthy diet choices, reducing hyperlipidemia, increasing physical activity, and adhering to prescribed medication therapy.

In addition to teaching about modifiable risk factors, clients should also receive health teaching about the following topics:

• Teaching the causes of strokes
• Ensuring clients and caregivers understand the signs and symptoms of stroke to ensure timely evaluation in the event of a recurrent stroke
• Ensuring clients and caregivers understand potential complications of therapy, especially bleeding, if they are discharged on an anticoagulant
• Using assistive devices, as advised by the therapy teams, to prevent the risk of falls

Evaluation

Evaluation of client outcomes refers to the process of determining whether or not client outcomes were met by the indicated time frame. This is done by reevaluating the client as a whole and determining if their outcomes have been met, partially met, or not met. If the client outcomes were not met in their entirety, the care plan should be revised and reimplemented. Evaluation of outcomes should occur each time the nurse assesses the client, examines new laboratory or diagnostic data, or interacts with a family member or other member of the client’s interdisciplinary team.