Study Notes on Stroke and Transient Ischemic Attack

Stroke Overview

  • Chapter 62
    • Presenter: Sarah Davis MSN, APRN, FNP-C

Stroke / CVA (Cerebrovascular Accident)

  • Etiology
    • Ischemia: Insufficient blood flow to the brain leading to cell death.
    • Hemorrhage: Bleeding in the brain that causes pressure and damage.
    • Severity Characteristics: Varies based on the location and extent of damage.

Risk Factors for Stroke

  • Nonmodifiable Risk Factors:

    • Age: Risk increases with age.
    • Gender: Males generally at higher risk.
    • Ethnicity: Certain ethnic groups are more susceptible.
    • Family History: Genetic predisposition may play a role.

  • Modifiable Risk Factors:

    • Hypertension (HTN): Major risk factor; must be controlled.
    • Heart Disease: Includes conditions like heart failure and arrhythmias.
    • Diabetes: Higher blood sugar can damage blood vessels.
    • Smoking: Contributes to clot formation and vascular damage.
    • Obesity: Associated with multiple metabolic issues that increase stroke risk.
    • Sleep Apnea: Potentially increases the risk of stroke due to poor oxygenation.
    • Metabolic Syndrome: Cluster of conditions such as hypertension and high blood sugar.
    • Sedentary Lifestyle: Regular activity is essential for cardiovascular health.
    • Poor Diet: Diet high in fat and cholesterol increases risk.
    • Drug/Alcohol Use: Excessive use can lead to various health issues contributing to stroke risk.

Transient Ischemic Attack (TIA)

  • Definition: A transient episode of neurologic dysfunction caused by focal brain, spinal cord, or retinal ischemia.
  • Symptoms Duration: Generally lasts less than 1 hour but can last up to 24 hours.
  • Clinical Significance: Considered a significant risk factor for future stroke.

Types of Stroke

  • Ischemic Stroke:

    • Embolism: A blood clot that travels from the heart to the brain.
    • Thrombosis: Blockage due to fatty plaque formation in blood vessels, leading to decreased blood flow.

  • Thrombotic Stroke:

    • Most common cause of stroke (60%).
    • Caused by injury to a blood vessel wall leading to clot formation.
    • Associated with atherosclerotic plaques.
    • Often preceded by a TIA.
    • Symptoms can progressively worsen.

  • Embolic Stroke:

    • Occurs when an embolus occludes a cerebral artery.
    • Second most common cause of stroke.
    • Often of cardiac origin.
    • Can present with severe and sudden clinical manifestations.

Clinical Manifestations of Stroke

  • Location Dependent Symptoms:
    • Motor Function: Impairment of movement in affected areas.
    • Communication: Difficulty in speech and understanding (aphasia).
    • Affect: Changes in emotional state and demeanor.
    • Intellectual Function: Cognitive deficits may occur.
    • Spatial-Perceptual Problems: Difficulty in spatial awareness and perception.
    • Elimination Problems: Issues with bowel and bladder control.

Diagnostic Studies for Stroke

  • CT (Computed Tomography): Quick imaging technique to identify bleeding and ischemia.
  • MRI (Magnetic Resonance Imaging): Detailed imagery for assessing stroke impact and location.
  • MRA (Magnetic Resonance Angiography): Visualizes blood vessels, identifying blockages.
  • TEE (Transesophageal Echocardiography): Evaluates heart structure and potential embolic sources.
  • Carotid Doppler: Assesses blood flow in carotid arteries.
  • Transcranial Doppler: Evaluates blood flow in the brain.
  • Fasting Lipid Profile: Assesses cholesterol levels related to risk.

Acute Care for Ischemic Stroke

  • Essentials:
    • Time of onset is critical for interventions.
    • ABCs (Airway, Breathing, Circulation) maintenance is crucial.
    • Maintain Oxygenation.
    • Blood Pressure management essential.
    • Fluid and Electrolyte Balance: Monitor and correct imbalances.
    • Drug Therapy: Utilization of thrombolytic agents.
    • Endovascular Therapy: Procedure to restore blood flow.

Tissue Plasminogen Activator (tPA)

  • Function: Localized fibrinolysis by binding to fibrin in thrombi, aiding reestablishment of blood flow.
  • Time frame for Administration: Must be administered within 3-4.5 hours of onset of symptoms (Golden Hour).
  • Careful Screening Required: To avoid complications and assess eligibility for therapy.

Time Goals for tPA (Golden Hour)

  • Door to Evaluation/Stroke Team: 15 minutes.
  • Door to CT/MRI Initiation: 25 minutes.
  • Door to EKG, Labs, Chest X-ray: 45 minutes.
  • Door to CT/MRI Interpretation: 45 minutes.
  • Door to tPA Administration: 60 minutes.

Retrieval Devices for Thrombectomy

  • Types of Devices:
    • Coil Retriever: Opens blocked arteries using a removable stent system.
    • Aspiration Device: Sucks the thrombus out using suction.
    • Stent Retriever: A self-expanding stent that entangles the thrombus and retrieves it into the catheter.
  • Mechanisms:
    • Nitinol Shape-memory: Utilized in devices for effective retrieval.
    • Vacuum aspiration via wire: Provides effective suctioning of thrombus material.

Nursing Management: Assessment

  • Focus Areas:
    • Cardiac and Respiratory Status: Continuous monitoring required.
    • Health History: Collect thorough data on patient’s background.
    • NIHSS (National Institutes of Health Stroke Scale): Essential for quantifying stroke severity.
    • Bedside Swallow Screen: Evaluate swallowing capabilities prior to any oral intake.
    • Neurological Assessment: Check mental status, motor responses, and sensory functions.

NATIONAL INSTITUTES OF HEALTH STROKE SCALE (NIHSS)

  • Scale Components:
    • Item responses scored from 0 (no impairment) to higher scores indicating increased severity.
    • Total Score Range: 0-42 points, with higher scores indicating more severe neurological impairment resulting from stroke.

NIH Stroke Scale - Example Items and Scoring Criteria

  • Level of Consciousness:
    • 0: alert, 1: drowsy, 2: obtunded, 3: coma/unresponsive.
  • Orientation Questions:
    • 0: answers both correctly, 1: answers one correctly, 2: answers neither.
  • Motor Function (arm and leg):
    • Scoring based on movement capabilities from 0 (no drift) to 4 (no movement).
  • Language and Articulation:
    • Scale assesses clarity of speech and ability to communicate effectively.

Nursing Management: Implementation

  • Health Promotion: Emphasizing risk reductions and lifestyle modifications.
  • Monitor Respiratory Status: Ensure patients maintain effective breathing.
  • Ongoing Neurological Assessments: Regular evaluations to detect changes.
  • Vital Signs & Input/Output Monitoring: Keep track of vital signs and fluid balances.
  • VTE (Venous Thromboembolism) Prophylaxis: Strategies to prevent blood clots.
  • Rehabilitation Practices:
    • ROM (Range of Motion) exercises: To maintain mobility.
    • Positioning: To prevent complications like pressure sores.
    • Nutritional Needs Assessment: Patients to be NPO until swallowing capabilities are confirmed.
    • Prevention of Constipation & Promotion of Normal Bladder Function: Essential for overall health.

Nursing Management: Communication Issues

  • Addressing Sensory-Perceptual Problems: Effectively managing deficits based on stroke location.
  • Coping Strategies: Encouraging emotional support and coping mechanisms for patients and families.
  • Care Transition: Ensuring smooth movement from acute care to rehabilitation or home care.

Review Questions

  • Factors placing a client at risk for a stroke:

    • A: Alcohol intake, B: Chronic A-Fib, C: Cigarette smoking, D: Diabetes Mellitus, E: Hypertension, F: Low Fat Diet (not a risk), G: Oral Contraceptive Use.

  • Patient Education on TIA: Patient should understand the need for medical attention post-TIA for potentially serious complications.

  • Priority Assessment for Stroke Recovery: Determine which of the following is critical (Risk for aspiration is priority over communication and mobility).

Concluding Remarks

  • Ensuring comprehensive understanding of stroke management entails knowledge of risk factors, early intervention, diagnostic assessments, treatment protocols, and ongoing patient care.