Stroke and Transient Ischemic Attacks

First Things First (assess & treat for the following)

  • Stroke Definitions & Background Information
  • Stroke = sudden brain dysfunction due to blood-vessel problem
  • Stroke types
    • Acute ischemic stroke (AIS) 87% = low blood flow to a focal area of brain, usually caused by thromboembolism
    • Intracerebral hemorrhage (ICH) 10% = bleeding into brain due to nontraumatic vessel rupture
    • Subarachnoid hemorrhage (SAH) 3% = bleeding around brain due to nontraumatic vessel rupture
  • Transient ischemic attack (TIA) = reversible brain dysfunction due to ischemia, typically lasting less than one hour (24-h limit is arbitrary and outdated) - i.e., this is an ischemic stroke without sequelae
  • Penumbra = zone of reversible ischemia around core of irreversible infarction that is salvageable in the first few hours after ischemic stroke onset
  • Etiologies of AIS and TIA
    • Large-artery disease (atherosclerosis)
    • Small-artery disease (lacunes)
    • Cardioembolism
    • Nonatherosclerotic vasculopathies (esp. arterial dissection)
    • Hypercoagulable states
    • Hypotension (causing watershed = border-zone infarctions)
  • Epidemiology in U.S.
    • 795,000 strokes/year—610,000 first, 185,000 recurrent
    • Third leading cause of death among adults
    • A leading cause of long-term disability
    • 28% occur in people age <65
    • Costs $68.9 billion/year
  • Initial Assessment Overview
  • Before imaging
    • Identify witness, determine last time known without symptoms
    • Determine if shaking or staring at symptom onset to suggest seizure
    • Avoid lowering BP— increased BP helps perfuse penumbra of ischemic stroke
    • Avoid aspiration—keep head >30 degrees & 100% NPO
    • Maintain O2 saturation >92% with 2-4 L O2 if necessary
    • Determine fingerstick glucose—treat if <50 mg/dL
    • Avoid hyperglycemia—do not give glucose-containing or hypotonic solutions; maintain glucose 60-150 mg/dL
    • Infuse IV NS 50-75 cc/hr
    • Draw & send STAT pre-tPA labs: CBC w platelets, basic chemistries, PT/INR, aPTT, cardiac panel
    • Obtain 12-lead ECG
    • Obtain STAT noncontrast CT brain
  • After imaging
    • Ischemic stroke—administer IV tPA if patient meets all criteria (see below), admit for etiologic evaluation, supportive care
    • TIA—admit (observation status) for rapid etiologic evaluation (see below)
    • ICH—admit for blood pressure management, supportive care
    • SAH—admit to ICU for coiling or clipping and supportive care

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Last updated: May 5, 2010