Stroke Overview and Classification

Stroke Overview

• Stroke is now known as "brain attack" to highlight the urgency
• Ischemic brain injury occurs when an arterial blockage lasts more than 2–3 hours

Stroke Definition

• Stroke is a descriptive term for the sudden onset of acute neurological deficit lasting longer than 24 hours
• Caused by interruption of blood flow to the brain

Stroke Epidemiology

• Approximately 795,000 people experience a stroke each year
• 610,000 are first-time attacks
• 185,000 are recurrent attacks
• Men have a higher incidence of stroke compared to women

Stroke Classification

• Early stroke type identification is crucial for appropriate treatment; incorrect treatment can be fatal
• Ischemic (80%): Thrombotic (75% - large vessel, 25% - small vessel "lacunar"); Embolic
• Hemorrhagic (20%): Intracerebral (67%); Subarachnoid (33%)

Stroke Risk Factors

• Age and sex
• Hypertension
• Hyperlipidemia
• Atrial fibrillation
• Prosthetic heart valves
• Diabetes mellitus
• Collagen disorders
• Smoking
• Oral contraceptive use
• Cardiac disease
• Recent neck trauma

Initial Assessment Tools

• Cincinnati Prehospital Stroke Scale: Facial droop, arm drift, abnormal speech; a score of 1 abnormal sign = 72% probability of a stroke.
• FAST: Facial drooping, arm weakness, speech difficulty, time to call 911. Patients should be assessed within 10 minutes of arrival in ED
• Immediate computed tomography (CT) scan is essential for further assessment

Ischemic Stroke

• Results from interruption of blood flow to the brain due to a thrombus or embolus blocking a cerebral artery.
• Emboli often arise from the heart, following atrial fibrillation, MI, or surgery
• Pathophysiology: Local thrombus/embolus, decreased blood flow, oxygen deprivation, microscopic necrosis of neurons, and infarction.
• Ischemic cascade begins within seconds to minutes after perfusion failure, forming an area of irreversible infarction with a surrounding region of potentially salvageable tissues termed the ischemic penumbra
• Goal of acute stroke management is to salvage the ischemic penumbra

Ischemic Stroke - Pathophysiology (Continued)

• After a large thrombotic stroke, massive cerebral edema and a rise in intracranial pressure (ICP) can occur causing herniation and death.

Clinical Manifestations of Stroke

• Sudden onset of facial weakness
• Sudden onset of unilateral weakness
• Sudden confusion or speech difficulty (expressive/receptive aphasia)
• Sudden headache, nausea, and vomiting (most common with hemorrhagic stroke)
• More subtle deficits may include: Dysphagia, sudden visual disturbance, ataxia, sudden numbness/tingling

Further Assessment and Diagnosis

• Question 1 (Is this a stroke?): Determine if symptoms are due to a stroke or a stroke mimic (seizures, syncope, or hypoglycemia/hyperglycemia).
• Question 2 (When did symptoms begin?): Obtain detailed time of symptom onset and last normal function from the patient, family, or bystanders.
• Question 3 (Are airway, breathing, and circulation adequate? ): Rapid assessment of ABCs before transport to CT.
• Question 4 (Are focal deficits present?): Initial neurological examination. Cincinnati Prehospital Stroke Scale.
• Question 5 (What immediate diagnostic procedures are recommended?): Immediate CT scan of the head, blood glucose, serum electrolytes and renal function tests, 12-lead EKG, cardiac biomarkers, complete blood count including platelet count, PT, INR, activated partial thromboplastin time (aPTT), oxygen saturation, lumbar puncture (if SAH is suspected and CT is negative for blood).

In-depth Neurological Examination

• American Stroke Association recommends the National Institutes of Health Stroke Scale (NIHSS) for assessing stroke deficits; conducted over 7 minutes; scores 0 (normal) to 20 (severe).

Therapeutic Interventions

• Brain Attack Coalition sets time goals for delivering stroke care within 6 hours (“last seen normal”)
• ED door-to-physician examination (10 minutes)
• ED door-to-CT scan completed (25 minutes)
• ED door-to-CT interpretation (45 minutes)
• ED door-to-needle [rt-PA started] (60 minutes)
• Goals of treating stroke patients: Restore blood flow, optimize hemodynamics and maintain cerebral perfusion; minimize damage and salvage penumbra;
• Establish adequate ABCs; supplemental oxygen if oxygen saturation is less than 92%, consider advanced airway as needed, obtain second IV line with normal saline solution.

Intravenous Thrombolytic Therapy

• Recombinant tissue-type plasminogen activator (rt-PA) is the approved treatment for ischemic stroke.
• Goal: Begin fibrinolytic therapy within 3 hours of symptom onset.
• Dose: 0.9 mg/kg, 10% IV bolus over 1 minute, 90% infusion over 1 hour

Inclusion/Exclusion Criteria for rt-PA

• Detailed inclusion and exclusion criteria to evaluate patients for thrombolytic therapy.

Nursing Interventions for rt-PA Patients—Before Administration

• Obtain accurate patient weight for dose calculation
• Explain risks and benefits to the patient and family
• Maintain SBP <185 mm Hg and DBP <110 mm Hg

Nursing Interventions for rt-PA Patients—During/After Administration

• Assess for complications (bleeding, angioedema, allergic reaction, worsening neurology)
• Perform neurological assessments and vital signs (every 15 minutes for the first 2 hours, then every 30 minutes for 4 to 6 hours)
• Elevate the head of the bed to 30 degrees (for patients with elevated ICP or respiratory problems); otherwise, maintain head of bed flat
• Record accurate intake and output
• Do not administer antithrombotics ( aspirin, heparin, clopidogrel, warfarin, NSAIDs) for 24 hours after rt-PA.
• Transfer to the ICU for close monitoring and treatment

Nursing Interventions for rt-PA Patients—During/After Administration (Continued)

• Document time of onset of stroke symptoms or “last seen normal”
• Document NIHSS on admission
• Document patient weight
• Document rt-PA dosage given
• Document time of the rt-PA bolus
• Document swallow screen results

Management of Blood Pressure in Stroke Patients

• Cautiously lower blood pressure (15–25% in first 24 hours) when indicated
• Labetalol (Trandate) is a first-line agent for stroke blood pressure control; working quickly, not too aggressive, and short acting.
• Dose: 10 mg IV over 1-2 minutes; up to 20 mg. Observe for change in BP.

Transient Ischemic Attacks (TIA)

• Brief episodes of neurological dysfunction from focal cerebral ischemia without permanent brain infarction.

TIA Risk Assessment—ABCD2 Scoring System

• Tool for predicting risk of stroke after TIA.
• Factors like age, blood pressure, clinical features, and duration of symptoms are used to assess risk.

Hemorrhagic Stroke

• Stroke due to intracranial hemorrhage, not ischemia
• Anticoagulants and fibrinolytics are contraindicated

Intracerebral Hemorrhage (ICH)

• Bleeding directly into brain tissue
• Causes: Hypertension, coagulopathy, anticoagulation, arteriovenous malformation (AVM), aneurysm, illicit drug use
• Clinical manifestations: Rapidly deteriorating neurological deficits, severe headache, vomiting, high blood pressure.

Subarachnoid Hemorrhage (SAH)

• Bleeding into the subarachnoid space
• Approximately 3% of all stroke cases
• High rate of disability and mortality (approximately 50% of patients die following initial injury)
• Causes: Cerebral aneurysms (family history, hypertension, cigarette smoking, female gender, increasing age, alcohol abuse, use of stimulants)
• Clinical manifestations are sudden/severe/unrelenting headache.

SAH—Diagnostic Procedures

• First-line imaging: CT scan without contrast
• CT negative: Lumbar puncture suspected SAH

SAH—Initial Treatment

• Prevent rebleeding of aneurysm
• Maintain systolic BP of 90–140 mm Hg
• Administer analgesics as needed
• Short-acting sedatives for agitated patients

SAH—Intensive Care Management

• Perform frequent neurological assessment
• Maintain body temperature < 37.5°C
• VTE prophylaxis (elastic stockings or pneumatic compression devices; avoid anticoagulants)
• Admission to an ICU.
• Surgical clipping/endovascular coiling of aneurysm; anticipate/initiate transfer to a tertiary center.

General Nursing Interventions for Different Stroke Types

• Establish ABCs (oxygen, airway, IV line)
• Perform frequent neurological assessments
• Maintain NPO until a swallow test is cleared
• Manage increased ICP
• Maintain normothermia
• Maintain serum glucose below 140 mm Hg
• Communicate effectively with the patient and family
• Provide supportive care

This quiz covers the essential aspects of strokes, including definitions, epidemiology, types, and risk factors. Understand the urgency surrounding strokes, their classification, and the importance of timely treatment. Perfect for anyone looking to enhance their knowledge on this critical health issue.