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Acute Stroke


Stroke should be suspected whenever a patient presents with the characteristic sudden onset of focal neurologic signs such as hemiparesis, hemisensory loss, hemianopia, aphasia, or ataxia ( Table 6.1 ). Time is of the essence for treating stroke because reperfusion therapy always works better when given as early as possible. It has been estimated that every 15-minute reduction in onset-to-treatment time translates into a meaningful reduction in the risk of long-term disability at 3 months.

Table 6.1
Presentations of Acute Stroke

  • Abrupt onset of facial or limb weakness (usually hemiparesis)

  • Sensory loss in one or more extremities

  • Sudden change in mental status (confusion, delirium, lethargy, stupor, or coma)

  • Aphasia (incoherent speech, lack of speech output, or difficulty understanding speech)

  • Dysarthria (slurred speech)

  • Loss of vision (hemianopic or monocular) or diplopia

  • Ataxia (truncal or limb)

  • Vertigo, nausea and vomiting, or headache

Because of the importance of early intervention in acute stroke, the emphasis of emergency room (ER) management should not be on identifying subtle, unusual, or interesting neurologic signs but on the following five priorities. When a STROKE CODE is called, tasks are ideally performed in parallel by four different personnel immediately on patient arrival (e.g., the emergency department [ED] attending, resident, nurse, and stroke neurologist):

  • 1.

    Assess level of consciousness and ensure adequate airway, breathing, and circulation.

  • 2.

    Obtain the history with precise attention to the specific time of onset (or discovery) of symptoms, along with a list of current medications.

  • 3.

    Establish large-bore (preferably 18-gauge) intravenous (IV) access, and obtain admission labs.

  • 4.

    Perform a National Institutes of Health Stroke Scale (NIHSS) examination.

  • 5.

    Obtain head noncontrast computed tomography (NCCT) and CT angiogram imaging as soon as possible.

It should be kept in mind that mortality is reduced and the likelihood of a good recovery is increased when stroke patients are cared for in a dedicated stroke unit. If your patient is unusually complex or critically ill, consideration should be given to transferring the patient to the nearest comprehensive stroke center once he or she has been stabilized.

This chapter focuses on the emergency management of stroke. Additional information regarding hospital care and long-term management can be found in Chapter 24 .

Phone call

Questions

  • 1.

    What were the presenting symptoms?

  • 2.

    Exactly when did the symptoms begin? If the symptoms were unwitnessed, what was the time last known well and time of discovery ?

  • 3.

    Have the symptoms worsened, fluctuated, or improved since onset?

  • 4.

    What are the vital signs?

  • 5.

    Does the patient have a history of hypertension, diabetes, or cardiac disease?

  • 6.

    Is the patient taking any antiplatelet agents or anticoagulants?

It is particularly important to perform an urgent CT scan on patients taking anticoagulants to rule out intracerebral hemorrhage (ICH), because early treatment reversal agents can be lifesaving.

Orders

  • 1.

    Establish an IV line with 0.9% normal saline (NS) at 1 mL/kg/h. Hypotonic fluids such as D5W and half-normal saline aggravate cerebral edema.

  • 2.

    Place a pulse oximeter and apply oxygen if there is respiratory distress or if the oxygen saturation is < 95%.

  • 3.

    Make sure the patient gets nothing by mouth (is made NPO).

  • 4.

    Place a portable cardiac monitor.

  • 5.

    Order a stat noncontrast head CT scan and a CT angiogram ( Box 6.1 ; Fig. 6.1 )

    Box 6.1
    CBF, Cerebral blood flow; CTA, computed tomography angiography; CTP, computed tomography perfusion; LVO, large-vessel occlusion; MT, mechanical thrombectomy; NIHSS, National Institutes of Health Stroke Scale score.
    Emergency Computed Tomography Angiography and Perfusion Imaging for Acute Stroke

    Increasingly, major stroke centers are routinely incorporating CTA into their acute stroke algorithms with the goal of detecting a treatable LVO (see Fig. 6.1 ). Early detection of LVO is crucial because this is the trigger for proceeding with MT. Stroke centers are increasingly using a CTA for All policy, in which a CTA is performed at the same time as the initial noncontrast CT for all stroke codes within 24 hours of last known well, regardless of the baseline NIHSS score.

    When an LVO is detected but the patient is presenting between 6 and 24 hours from last known well, CTP imaging is then performed to help identify good candidates for thrombectomy. Automated image analysis software calculates the volume (in milliliters) of core infarction (CBF < 30% of normal), ischemic penumbra (mismatch volume, T max > 6.0 seconds) and mismatch ratio (mismatch/core volume).

    In these protocols routine documentation of a normal serum creatinine level is waived because of the urgency of the situation and the low risk of serious contrast-induced nephropathy (< 1%). Demonstration of a treatable LVO then triggers an interventional “secondary page” that mobilizes the interventional team with the goal of beating a 60-minute “picture-to-puncture” time interval.

    Fig. 6.1, Computed tomographic angiogram demonstrating occlusion of the M1 segment of the left middle cerebral artery (blue arrow). Filling of the anterior temporal branches is evident just proximal to the site of occlusion. Posteriorly, there is markedly reduced filling of the sylvian branches of the middle cerebral artery compared with the contralateral side.

  • 6.

    Order and draw the following diagnostic blood tests, but do not delay imaging or treatment waiting for lab test results.

    • Complete blood count (CBC) and platelet count

    • Serum chemistries (glucose, electrolytes, blood urea nitrogen [BUN], creatinine)

    • Prothrombin time (PT)(international normalized ratio [INR])/partial thromboplastin time (PTT)

    • Cardiac troponin level

Elevator thoughts

What are the causes of stroke?

  • 1.

    Infarction: causes 80% of all strokes

    • a.

      Embolic

      • (1)

        Cardiogenic embolism

        • (a)

          Atrial fibrillation or other arrhythmia

        • (b)

          Left ventricular mural thrombus

        • (c)

          Mitral or aortic valve disease

        • (d)

          Endocarditis (infectious or noninfectious)

      • (2)

        Embolic stroke of unknown source (ESUS)

      • (3)

        Paradoxical embolism (patent foramen ovale)

      • (4)

        Aortic arch embolism

    • b.

      Atherothrombotic (large-vessel or medium-vessel disease)

      • (1)

        Extracranial disease

        • (a)

          Internal carotid artery (ICA)

        • (b)

          Vertebral artery

      • (2)

        Intracranial disease

        • (a)

          ICA

        • (b)

          Middle cerebral artery (MCA)

        • (c)

          Basilar artery

    • c.

      Lacunar (small penetrating artery occlusion)

    • d.

      Other or unknown

  • 2.

    ICH: causes 15% of all strokes

    • a.

      Hypertensive

    • b.

      Amyloid angiopathy

    • c.

      Arteriovenous malformation (AVM)

  • 3.

    Subarachnoid hemorrhage (SAH): causes 5% of all strokes

    • a.

      Aneurysmal (80%)

    • b.

      Nonaneurysmal (20%)

  • 4.

    Miscellaneous causes (can lead to infarction or hemorrhage)

    • a.

      Dural sinus thrombosis

    • b.

      Carotid or vertebral artery dissection

    • c.

      Central nervous system (CNS) vasculitis

    • d.

      Moyamoya disease (progressive intracranial large artery occlusion)

    • e.

      Migraine

    • f.

      Hypercoagulable state

    • g.

      Drug abuse (cocaine or other sympathomimetics)

    • h.

      Hematologic disorders (sickle cell anemia, polycythemia, or leukemia)

    • i.

      Mitochondrial encephalopathy, lactic acidosis, and stroke (MELAS)

    • j.

      Atrial myxoma

Major threat to life

  • Transtentorial herniation

    Occurs primarily in the following presentations:

    • 1.

      Massive hemispheric infarction or hemorrhage

    • 2.

      Intraventricular extension of ICH or SAH

  • Cerebellar infarction or hemorrhage

    All patients with large cerebellar lesions require neurosurgical evaluation because emergent decompression can be lifesaving.

  • Aspiration

    Aspiration pneumonia is a common cause of death in stroke patients. All patients should be considered to have impaired swallowing until proven otherwise.

  • Myocardial infarction (MI)

    Acute MI complicates approximately 3% of acute ischemic strokes.

Bedside

Quick-Look Test

  • What is the patient’s level of consciousness?

The urgency of the situation can be assessed immediately by evaluating the level of consciousness. Patients in stupor or coma are at the highest risk for further deterioration and are most likely to benefit from urgent intervention.

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