Ischemic stroke resident survival guide

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Ayokunle Olubaniyi, M.B,B.S [2]

Overview

Ischemic stroke is defined as an episode of neurological dysfunction caused by focal cerebral, spinal, or retinal infarction. Infarction of the central nervous system serves as the main pathogenetic mechanism implicated in the etiology of ischemic stroke. CNS Infarction refers to brain, spinal cord, or retinal cell death attributable to ischemia, based on:

1. Pathological, imaging, or other objective evidence of cerebral, spinal cord, or retinal focal ischemic injury in a defined vascular distribution; or

2. Clinical evidence of cerebral, spinal cord, or retinal focal ischemic injury based on symptoms persisting ≥24 hours or until death, and other etiologies excluded.

CNS infarction also include:

• Hemorrhagic infarction ("hemorrhagic transformation of infarction", "hemorrhagic conversion of infarction") - This may occur spontaneously or due to antithrombotic or thrombolytic treatment. They generally lack a mass effect, and are managed according to ischemic stroke recommendations. There are two types:

Type I - petechiae of blood along the margins of the infarction.

Type II - confluent petechiae within the infarction but without a space-occupying effect.

Time of Onset

Time of onset is defined as when the patient was last awake and symptom-free or known to be “normal".

Causes

Life Threatening Causes

Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated.

• All the causes of stroke are life-threatening.

Common Causes

Ischemic Stroke

• Embolic causes: Cardiac arrhythmias, infective endocarditis, left atrial myxoma, cardiomyopathy, atrial or ventricular thrombus

• Thrombotic causes: Atherosclerosis of large vessels , arteritis/vasculitis, dissection, Takayasu arteritis

• Systemic hypoperfusion (Watershed stroke): Myocardial infarction, cardiac arrhythmias, pericardial effusion, pulmonary embolism

Management

Within the First 24 Hours

Acute Ischemic Stroke

Time of Onset

<3 hours

3 - 4.5 hours

>4.5 hours

Eligibility criteria for IV rTPA (see below)

Consider rTPA after reviewing the additional exclusion criteria for this category (see below)

Eligible

Not eligible

Blood Pressure Management Treat fever with IV antipyretics (acetaminophen)

BP≤180/110

BP≥180/110

IV rTPA 0.9 mg/kg (maximum of 90 mg). Give the first 10% as IV bolus over 1 minute, then give the remaining as IV infusion over 1 hour

Ensure BP<180/110 mmHg before initiating rTPA (see Blood Pressure Management)

Admit ICU (for BP monitoring + bleeding complications) Hourly vitals and neurocheck Aspiration precautions

After 24 Hours

After 24 hours post rTPA or no rTPA

Follow-up head CT/MRI before commencing antiplatelets to r/o secondary hemorrhage

Specific measures: ❑ ASA 325 mg (if no contraindication) ❑ Statins ❑ DVT prophylaxis

General measures: ❑ Frequent vitals and neurochecks ❑ Cardiac monitoring (to screen for afib) ❑ Optimal BP control ❑ Airway and ventilatory support (in ↓consciousness) ❑ Supplemental O2 (if SaO2 <94%) ❑ Maintain normothermia (T <38oC) ❑ Maintain normovolemia - IV normal saline ❑ Achieve normoglycemia (SG 90 - 140 mg/dL) ❑ ‡ Patient positioning ❑ Early mobilization after 24 - 48 hours of less severely affected patients ❑ PT/OT evaluation ❑ Speech and swallow evaluation

Investigate the etiology: ❑ MRA/CTA/carotid duplex ❑ Venous doppler USS ❑ Echocardiography Ages 18-45 years: ❑ Proteins C & S assay ❑ Antithrombin III assay ❑ Factor V Leiden mutation ❑ Prothrombin mutation ❑ Lupus anticoagulant ❑ Anti-cardiolipin antibodies ❑ Hemoglobin electrophoresis ❑ VDRL ❑ Toxicology screen ❑ CSF analysis ❑ Holter monitoring

Manage Complications

Hemorrhagic Infarction Continue with present management

TPA-Induced Parenchymal Hemorrhage

TPA Reversal Give Cryoprecipitate (1-2 U/10 Kg) Plus Platelet transfusion (titrate according to follow-up labs)

Consult to Neurosurgery Consider repeat CT to assess hemorrhage size

‡ Patient positioning:

• Supine position is preferred if there is no risk of elevated ICP or aspiration.
• Nurse at 15 - 30 degrees head-of-bed elevation if there is risk of elevated ICP, aspiration or cardiopulmonary compromise.
• Prevent pressure sores - frequent turning.

Management of Blood Pressure

Blood Pressure Management

Review Exclusion Criteria for IV rTPA Administration

Eligible

Not eligible

Before treatment

During/After treatment

BP <220/120 mmHg

BP >220/120 mmHg

BP>185/110 mm Hg Labetalol 10–20 mg IV over 1–2 minutes, may repeat 1 time; or nicardipine 5 mg/h IV infusion; titrate up by 2.5 mg/h every 5–15 minutes, maximum 15 mg/h; when desired BP reached, adjust to maintain proper BP limits; or other agents (hydralazine,enalaprilat, e.t.c.) may be considered when appropriate

Observe unless evidence of end-organ damage is present (e.g., acute myocardial infarction, aortic dissection, pulmonary edema, hypertensive encephalopathy) Conservative management - treat fever, pain, headaches, nausea, vomiting

Labetalol 10–20 mg IV over 1–2 minutes, may repeat or double every 10 minutes (maximum dose of 300 mg); or nicardipine 5 mg/h IV infusion; titrate up by 2.5 mg/h every 5–15 minutes, maximum 15 mg/h Aim at 15% reduction during the first 24 hours after stroke onset

SBP>180–230 mm Hg or DBP >105–120 mm Hg

BP not controlled or DBP >140 mm Hg

Labetalol 10 mg IV followed by continuous IV infusion 2–8 mg/min; or nicardipine 5 mg/h IV, titrate up to desired effect by 2.5 mg/h every 5–15 minutes, maximum 15 mg/h

Sodium nitroprusside 0.5 mcg/kg/min IV infusion as initial dose, then titrate to desired blood pressure

All algorithms are based on recommendations from AHA/ASA for the early management of patients with acute ischemic stroke (2013)

Exclusion Criteria for IV Recombinant TPA Treatment

Less than 3 hours of onset

• Significant head trauma or prior stroke in previous 3 months
• Symptoms suggest subarachnoid hemorrhage
• Arterial puncture at noncompressible site in previous 7 days
• History of previous intracranial hemorrhage
• Intracranial neoplasm, arteriovenous malformation, or aneurysm
• Recent intracranial or intraspinal surgery
• Elevated blood pressure (systolic >185 mm Hg or diastolic >110 mm Hg)
• Active internal bleeding
• Acute bleeding diathesis, including but not limited to
• Platelet count <100,000/mm³
• Heparin received within 48 hours, resulting in abnormally elevated aPTT greater than the upper limit of normal
• Current use of anticoagulant with INR >1.7 or PT >15 seconds
• Current use of direct thrombin inhibitors or direct factor Xa inhibitors with elevated sensitive laboratory tests (such as aPTT, INR, platelet count, and

ECT; TT; or appropriate factor Xa activity assays)

• Blood glucose concentration <50 mg/dL (2.7 mmol/L)
• CT demonstrates multilobar infarction (hypodensity >1/3 cerebral hemisphere)

Relative exclusion criteria

• Only minor or rapidly improving stroke symptoms (clearing spontaneously)
• Pregnancy
• Seizure at onset with postictal residual neurological impairments
• Major surgery or serious trauma within previous 14 days
• Recent gastrointestinal or urinary tract hemorrhage (within previous 21 days)
• Recent acute myocardial infarction (within previous 3 months)

Between 3 and 4.5 hours of onset

• Aged >80 years
• Severe stroke (NIHSS>25)
• Taking an oral anticoagulant regardless of INR
• History of both diabetes and prior ischemic stroke

Dos

• Obtain a brief history, including time of onset, time of arrival at the ED, and medications (especially anticoagulants).
• Rule out conditions mimicking stroke (i.e., Seizures, syncope, migraine with aura, hypoglycemia, hypertensive encephalopathy, Wernicke encephalopathy, CNS abscess, CNS tumor, drug toxicity (lithium, phenytoin, carbamazepine)
• Review the criteria for the administration of IV rTPA to determine the patient's eligibilty status.
• Order a limited number of investigation during the initial emergency evaluation. Only the estimation of blood glucose should precede the administration of IV rTPA.
• Cardiac monitoring for at least the first 24 hours to screen for atrial fibrillation.
• Ensure blood pressure of ≤180/110 mmHg before initiating IV rTPA, and maintain it below 180/105 mmHg for at least the first 24 hours post-IV rTPA.
• Order a follow-up CT/MRI before commencement of antiplatelets.
• Give ASA 325 mg within 24 to 48 hours to most patients (except if contraindicated).
• Strict blood pressure monitoring for the first 24 hours, especially if rTPA was administered - every 15 minutes for 2 hours, then every 30 mins for 6 hours, and every hour for the next 16 hours.

Don'ts

• Do not treat hypertension except the blood pressure is >220/120 mmHg, and not until CT/MRI have been performed.
• Do not initiate anticoagulation treatment within the first 24 hours.
• Do not commence oral administration of medications before speech and swallow evaluation.
• Do not delay sending the patient to CT for any reason.