The most effective way to decrease the burden of stroke is prevention. Non-modifiable risk factors include age, gender, race, and heredity.
Hypertension is the single most important modifiable risk factor; others include increased serum cholesterol, smoking, excessive alcohol consumption, obesity, physical inactivity, poor diet, and drug abuse.
Several conditions are associated with stroke risk, including atrial fibrillation, cardiac valve abnormalities, and diabetes mellitus.
The brain requires a continuous supply of blood to provide the oxygen and glucose that neurons need to function. Blood flow must be maintained at 750 to 1000 mL/min (55 mL/100 g of brain tissue), or 20% of the cardiac output, for optimal brain functioning. If blood flow to the brain is totally interrupted (e.g., cardiac arrest), neurologic metabolism is altered in 30 seconds, metabolism stops in 2 minutes, and cellular death occurs in 5 minutes. The brain is normally well protected from changes in mean systemic arterial blood pressure (BP) over a range from 50 to 150 mm Hg by a mechanism known as cerebral autoregulation.
Factors that affect blood flow to the brain include systemic BP, cardiac output, and blood viscosity. During normal activity, oxygen requirements vary considerably, but changes in cardiac output, vasomotor tone, and distribution of blood flow normally maintain adequate blood flow to the head. Cardiac output has to be reduced by one third before cerebral blood flow is reduced. Changes in blood viscosity affect cerebral blood flow, with decreased viscosity increasing flow.
Ischemic Stroke: A transient ischemic attack (TIA) is a transient episode of neurologic dysfunction caused by focal brain, spinal cord, or retinal ischemia, but without acute infarction of the brain. Clinical symptoms typically last less than 1 hour. Although most TIAs resolve, one third will progress to an ischemic stroke.
An ischemic stroke results from inadequate blood flow to the brain from partial or complete occlusion of an artery and accounts for approximately 80% of all strokes. Ischemic strokes are further divided into thrombotic and embolic.
A thrombotic stroke occurs from injury to a blood vessel wall and formation of a blood clot. The lumen of the blood vessel becomes narrowed, and if it becomes occluded, infarction occurs.
The extent of the stroke depends on rapidity of onset, the size of the lesion, and the presence of collateral circulation.
A lacunar stroke refers to a stroke from occlusion of a small penetrating artery with development of a cavity in the place of the infarcted brain tissue. Although a large percentage of these are asymptomatic, when present, symptoms can cause considerable deficits.
Embolic stroke occurs when an embolus lodges in and occludes a cerebral artery, resulting in infarction and edema of the area supplied by the involved vessel. The patient commonly has a rapid occurrence of severe clinical symptoms. Prognosis is related to the amount of brain tissue deprived of its blood supply.
The clinical manifestations are related to the location of the stroke.
A stroke can have an effect on many body functions, including motor activity, bladder and bowel elimination, intellectual function, spatial-perceptual alterations, personality, affect, sensation, swallowing, and communication.
Motor deficits include impairment of mobility, respiratory function, swallowing and speech, gag reflex, and self-care abilities.
The patient may experience aphasia, dysphasia, and dysarthria (disturbance in the muscular control of speech).
Patients may have difficulty controlling their emotions. Both memory and judgment may be impaired as a result of stroke.
A stroke on the right side of the brain is more likely to cause problems in spatial-perceptual orientation, including agnosia, apraxia, and unilateral neglect.
During the acute phase following a stroke, management of the respiratory system is a nursing priority. Stroke patients are particularly vulnerable to respiratory problems, including atelectasis, airway obstruction, and aspiration pneumonia.
The patient's neurologic status must be monitored closely to detect changes suggesting extension of the stroke, increased ICP, vasospasm, or recovery from stroke symptoms.
Nursing goals for the cardiovascular system are aimed at maintaining homeostasis; the nurse must perform a thorough cardiac assessment, manage infusions, and monitor fluid balance. Measures to prevent deep venous thrombosis (DVT) are often implemented.
To maintain optimal function of the musculoskeletal system, measures are used to prevent joint contractures and muscular atrophy.
The skin of the patient with stroke is particularly susceptible to breakdown related to loss of sensation, decreased circulation, and immobility.
The most common bowel problem for the patient who has experienced a stroke is constipation. Patients may be prophylactically placed on stool softeners and/or fiber.
The primary urinary problem is poor bladder control, resulting in incontinence. Efforts should be made to promote normal bladder function and to avoid the use of indwelling catheters.
The patient may initially receive IV infusions to maintain fluid and electrolyte balance, as well as for administration of drugs. Patients with severe impairment may require enteral or parenteral nutrition support. Swallowing ability will need to be assessed.
Assess the patient both for the ability to speak and the ability to understand and support the patient accordingly.
Homonymous hemianopsia (blindness in the same half of each visual field) is a common problem after a stroke. Persistent disregard of objects in part of the visual field should alert you to this possibility.
A stroke is usually a sudden, extremely stressful event for the patient, caregiver, family, and significant others. Use nursing interventions designed to facilitate coping by providing information and emotional support.
The patient is usually discharged from the acute care setting to home, an intermediate or long-term care facility, or a rehabilitation facility.
Regardless of the care setting, ongoing rehabilitation is essential to maximize the patient's abilities. Rehabilitation requires a team approach so the patient and family can benefit from the combined, expert care of a stroke team.
The goals for rehabilitation of the patient with stroke are mutually set by the patient, family, nurse, and other members of the rehabilitation team.
Initially you emphasize the musculoskeletal functions of eating, toileting, and walking for the rehabilitation of the patient. Interventions advance in a manner of progressive activity.
After the acute phase, a dietitian can assist in determining the appropriate daily caloric intake based on the patient's size, weight, and activity level. The diet must also be adjusted for the ability of the patient to swallow solids and fluids.
A bowel management program is implemented for problems with bowel control, constipation, or incontinence. Nursing measures are also focused on promoting urinary continence.
Patients who have had a stroke frequently have perceptual deficits. For example, patients with a stroke on the right side of the brain usually have difficulty in judging position, distance, and rate of movement.
The patient with a stroke may experience many losses, including sensory, intellectual, communicative, functional, role behavior, emotional, social, and vocational losses. As a nurse, you should help patients and families cope with these losses.
Speech, comprehension, and language deficits are the most difficult problems for the patient and family. Speech therapists can assess and formulate a plan of care to support communication.