Reference:
- Lecturers (Rotairo, VJVS)
Any functional abnormality of the cerebral nervous system, also called a “brain attack”, cerebral infarction, cerebral hemorrhage, ischemic stroke, or simply a stroke. This is caused by an interruption of the blood supply to the brain, often from an aneurysm or an obstruction, resulting in damage to the brain tissue and neurological deficits that usually last for more than 24 hours.
Etiology
- Ischemic Stroke: 85% of strokes; this is a stroke resulting from obstruction of blood vessels, often due to atherosclerosis. Atherosclerosis is a deposition of fatty substances, cholesterol, and cellular waste products, calcium, and other substances in the inner lining of an artery. Collectively, this build-up is referred to as “plaque”.
- Cerebral Thrombosis: clotting in an artery that supplies a vital brain center, commonly due to atherosclerosis of the carotid or vertebral arteries. In atherosclerotic causes of stroke, the time it takes for blood flow to become disrupted gives it the pseudonym of a “stroke in evolution”. Symptoms develop slowly.
- Cerebral Embolism: a blood clot travels into the brain’s blood vessels, shutting off blood supply. In embolic causes of stroke, symptoms develop quickly.
- Hemorrhagic Stroke: 15% of strokes; this is a stroke resulting from bleeding into the surrounding brain tissue (intracerebral, intraventricular, subarachnoid) from a ruptured blood vessel. These are primarily caused by uncontrolled hypertension. This may also be caused by an arteriovenous malformation. This is more life-threatening than ischemic strokes.
- Cerebral Hemorrhage: an artery bursts as the aneurysm wall bursts potentially from a severe rise in blood pressure, causing hemorrhage and ischemia.
The risk factors for cerebrovascular accidents vary, but many are related to lifestyle factors. These are divided between modifiable and non-modifiable risk factors:
- Non-modifiable: age, sex (males), race, heredity
- Modifiable: hypertension, diabetes, transient ischemic attacks (modified with aspirin use), hyperlipidemia, obesity, heart disease, oral contraceptive use (risk for emboli formation), physical inactivity, stenosis, hypercoagulability, cigarette smoking, and alcohol abuse.
Vs. Transient Ischemic Attacks
TIAs are “mini-strokes” which are periods of ischemia that does not result in acute infarction. As such, no long-term neurological defects occur, persisting not more than 24 hours.
Stages of a CVA
- Transient Ischemic Attack (TIA): short-lived obstructions of blood flow. These are “mini strokes” and are a warning sign for a progressive cerebrovascular disease.
- Temporary loss of neurologic function may occur, but only last less than one day and often less than even fifteen minutes. Most of these resolve within three hours.
- Reversible Ischemic Neurologic Deficit (RIND): these are TIAs that begin to produce symptoms that last up to a week.
- Stroke In Evolution (SIE): gradually worsening symptoms of brain ischemia
- Completed Stroke (CS): the symptoms of the stroke stabilize and rehabilitation can begin.
Clinical Manifestations - Warning Signs
- Increased ICP (which results in some of the other clinical manifestations) can be caused by or cause stroke.
- Contralateral hemiplegia (see side-specific manifestations below).
- This may result in neglect syndrome/unilateral neglect.
- Sudden weakness, paralysis, or numbness of the face, arm, or leg especially on one side of the body.
- Facial dropping on one side of the face.
- Sudden dimness or loss of vision in one or both eyes, potentially including uncontrollable eye movements (nystagmus) or eyelid drooping (ptosis).
- Hemianopsia: loss of half of the vision in one eye.
- Homonymous hemianopsia: loss of half vision on the same half of both eyes.
- Bitemporal hemianopsia: loss of half vision on the lateral halves of eyesight.
- Quadrantanopia: loss of vision in one quadrant in one eye.
- Sudden loss of speech/comprehension (dysarthria), slurring, confusion, or difficulty speaking or understanding speech.
- Dysarthria is the inability to cognitively produce comprehensible sentences. Comparatively, dysphonia is the inability to physically enunciate appropriate words.
- Unexplained sudden dizziness, unsteadiness, loss of balance, or coordination (ataxia).
- Ataxia can be assessed with the finger-to-nose and heel-to-shin tests.
- Sudden, severe headache.
- Swallowing difficulties or drooling may also occur.
- Loss of memory during the attack may occur.
- Personality changes, mood changes, and changes in the level of consciousness may occur.
Left-Sided Cerebrovascular Accident
Intellect is affected, affecting language, cognition, memory, analysis, judgment, and comprehension. Behaviors are slow and cautious.
- Right-sided hemiplegia
- Impaired speech and language: Aphasia, problems with both language expression and comprehension.
- Broca’s Expressive Aphasia: inability to express one’s thoughts into words appropriately.
- Wernicke’s Receptive Aphasia: inability to understands words appropriately.
- Global Aphasia: the presence of both expressive and receptive aphasia.
- Agnosia: the inability to recall the names of familiar objects.
- Slow performance and impaired comprehension
- Visual field deficits
- Aware of deficits, depression, and anxiety may occur
Right-Sided Cerebrovascular Accident
The patient with a right-sided CVA can develop risky, impulsive, aggressive, and violent personalities.
- Left-sided hemiplegia
- Spatial-perceptual deficits: increased risk for falls and injury (along with impaired judgment)
- Short attention span, impaired concept of time
- Impaired judgment, impulsive
- Unaware of problems; minimizes problems
Diagnosis
- A CT Scan (non-contrast) is the primary method of diagnosis, being able to identify the size and location of the CVA, and differentiates between ischemic and hemorrhagic type of strokes. Furthermore, a CT Angiography can visualize the vasculature of the brain.
- An ultrasound can show blood flow in the head via carotid doppler studies.
- An MRI is also able to visualize the brain, but is slower.
- CBG may also be performed, as hypoglycemia may mimic a stroke.
The FAST Method
In a pre-hospital setting, the F.A.S.T. method may be used:
- Face: ask the person to smile. Is one side or both sides of the face droopy?
- Arms: ask the person to raise both arms. Are one of the arms drifting downward or not equal to the other?
- Speech: ask the person to repeat a simple sentence. Is their speech slurred, strange, or slow?
- Time: time is highly important in caring for a patient undergoing a stroke. Get help and emergency services as soon as possible once the presence of a stroke is suspected.
Complications
- Re-bleeding
- Cerebral Vasospasm, which may produce/worsen cerebral ischemia
- Acute Hydrocephalus if the ventricular system of the brain becomes dysfunctional
- Seizures
- Motor, sensory, cranial nerve, cognitive, and other functional deficits
Medical Management
- Ischemic Stroke
- Permissive Hypertension may be used for patients with an ischemic stroke to maintain perfusion.
- Thrombolytic Therapy is used for thrombotic or embolic strokes. The gold standard thrombolytic used is Alteplase IV r-tPA via IV. This is used within three to four and a half hours of a stroke, the window time for giving the thrombolytic to prevent permanent deficits. This is followed up with antiplatelets after 24 hours for prophylaxis.
- Neurosurgical interventions can be used for a thrombectomy (removal of the thrombus) or a carotid endarterectomy (removal of carotid plaques as prophylaxis)
- Hemorrhagic Stroke
- Reverse anticoagulants halt bleeding: Vitamin K, fresh frozen plasma (FFP), cryoprecipitate
- Neurosurgical interventions can be used for unruptured aneurysms to mitigate the risk of a hemorrhaging stroke. In patients who has undergone hemorrhaging stroke, surgery can be used to remove formed hematomas.
| Indication | Treatment |
|---|---|
| Hypoglycemia | D50 Infusion |
| Hyperglycemia (>200 mg/dL) | Insulin |
| Hypertension | Labetalol 10-20 mg IVP repeated q10-20min |
| Nicardipine 5 mg/h, titrate by 2.5 mg/h q5-15min max. 15 mg/h, lower to 3 mg/hr once target BP is reached | |
| Enalapril 1.25 mg IVP | |
| Sodium nitroprusside (0.5 mcg/kg/min) | |
| Possible Ischemic Changes or Atrial Fibrillation | Continuous cardiac monitoring, thrombectomy (removal of thrombus), anticoagulant therapy, and antiepileptic therapy |
| IVF Therapy | Isotonic sodium chloride (NSS) at 50 mL/hr unless otherwise indicated; avoid D5W and excess administration |
| Aspiration | NPO status until swallowing is assessed. |
| Hypoxia | Maintain patent airway; oxygenation therapy if SaO2 is <94%. |
| Hyperthermia | Antipyretics: rectal or oral acetaminophen and cooling blankets as needed |
| Positioning | Lying flat or head elevated (30 degrees) |
| Aneurysm (hemorrhagic stroke) | Surgery is used to secure a blood vessel at the base of the aneurysm. |
| Correct/prevent obstruction | The gold standard thrombolytic used is Alteplase IV r-tPA via IV. This is used within three to four and a half hours of a stroke, the window time for giving the thrombolytic to prevent permanent deficits. |
Nursing Management
- Assessment: ABCs, VS, Neurologic Screening, 12-lead ECG, CBG monitoring, admittance to the stroke unit if no surgery will be done.
- Management: oxygen therapy (if hypoxic), blood glucose correction if indicated, and general supportive therapy.
- Nursing Diagnoses
- Ineffective tissue perfusion r/t decreased cerebrovascular blood flow
- Ineffective airway clearance r/t level of consciousness
- Impaired physical mobility
- Impaired verbal communication
- Impaired swallowing r/t loss of reflux
- Unilateral neglect r/t visual field cut and sensory loss
- Impaired urinary elimination
- Situational low self-esteem r/t actual or perceived loss of function
- Interventions:
- Maintain skin integrity
- Maintain airway patency and apply oxygen therapy if indicated.
- Monitor neurological status. Avoid activities that may cause elevations in ICP: neck flexion, hip flexion, straining, carrying heavy (>5 lb) objects, coughing, vomiting, bearing down, etc.
- Encourage PROM to affected extremities, and AROM to the unaffected extremities every two hours.
- Encourage independence during ADLs. Do not perform the patient’s care activities.
- Elevate the affected extremities to promote venous return and to reduce swelling.
- Maintain a safe environment to reduce risk of injury. Apply seizure precautions. A seizure will also increase ICP.
- Diet Therapy:
- Initially, the patient is kept on NPO.
- During feedings, the patient may flex the neck in order to enhance swallowing by closing the airway, preventing aspiration.
- Position the patient upright (high-Fowlers) during feedings.
- Sedation should minimally coincide with meals.
- Puree diet is used for patients in recovery. Fluids are thickened to prevent aspiration. Fluids are thickened to prevent aspiration.
- Rehabilitation is began the same day the patient is admitted.
- Placement of belongings: during the acute stage, items are placed on the patient’s unaffected side. As recovery improves, the nurse promotes independence and care of the affected side by placing objects on their affected side.
- Ambulation assistance: the best assistive walking device (AWD) for a stroke patient with hemiplegia is a cane held at the unaffected side. The nurse stands on the affected side.
- For the surgical patient undergoing thrombectomy
- Teach the scanning technique: turning the head side-to-side when eating and ambulating to compensate for hemianopsia.
- Provide care to prevent deep vein thrombosis: sequential compression stockings, frequent position changes, mobilization
- Educate the client on the prevention of a stroke: lifestyle changes (diet, weight control, exercise, avoid alcohol and smoking, and other risk factors), routine health assessment (check cholesterol levels (LDL <70 mg/dL), blood pressure control, blood glucose)