CanadiEM Frontline Primer

CanadiEM Frontline Primer – Ischemic Stroke

In Medical Concepts by Luciana CataneseLeave a Comment

Can’t Miss Diagnoses

  • Proximal/Large Vessel Occlusion (LVO)
  • Symptomatic carotid Artery Stenosis
  • Embolic Stroke due to Atrial Fibrillation
  • Intracranial Hemorrhage
Common Mimics
  • Seizure
  • Migraine
  • Bell’s Palsy
  • Vestibular Neuropathy

Points to focus upon

Hx:
  1. VERY IMPORTANT → Last known well time from patient if reliable or witness if not. Do not just go by what EMS says, may not accurate due to time constraints.
  2. Brief HPI on how the patient was found or what lead to the event/if witnessed. Listen to the EMS report. Sometimes they gathered info that cannot be found anywhere else.
  3. Past medical history (pertinent + only including recent bleeding, prior ICH, known AF, metastatic ca with life expectancy <6 months, cardiovascular RF)
  4. Medication list (mainly anticoagulants/anti-platelets, can look at rest after treatment)
  5. Baseline functional status (ask for specific ADLs, walking unassisted and if the patient can be left alone for a day at a time – most elderly cannot although “independent” per family)
Px:
  1. ABCs – Is the patient protecting their airway? Stroke patients desaturate late, aspirate early.
  2. Blood pressure (~5% of acute ischemic stroke patients have normal BP on arrival).
  3. Capillary blood sugar – If <4 correct but if symptoms persist, proceed with stroke eval.
  4. NIH Stroke Scale (use App. on phone to help calculation – see below)
  5. If administering tPA, perform a thorough baseline airway assessment (just in case the patient develops angioedema later).
Other Points
  1. Use parallel processing with a separate person filling out requisitions and consent for contrast, doing chart review, and obtaining collateral information when needed.

Investigations​1,2​

  1. Bloodwork: CBC, INR/PTT, RBG, electrolytes, Creatinine, Troponin
  2. Imaging
  3. EKG (this should wait until after treatment decision has been made) – Look for Atrial Fibrillation!

If the patient presented within 6 hours from last known well, perform:
CT head + CTA carotids(multiphase)*

If the patient presented beyond 6 hours from last known well and they are independent at baseline and have an NIHSS>6, perform:
CT Head + CTA arch to vertex (multiphase) + CT Perfusion (RAPID), if available.

*CT head + CTA should be performed for all patients presenting with symptoms of acute ischemic stroke, as well as for patients with high-risk TIAs (symptoms of unilateral motor weakness, speech difficulties, monocular blindness, or visual field defect). If outside window or TIA, ask for CTA arch to vertex without multiphase/post-contrast serial images*

Clinical Decision Tools

Management​1,2​

Liaise with your regional stroke program or neurology team to decide on the next steps. In some centres, you may be asked to provide alteplase or other thrombolytics.

Acute Ischemic Stroke

If within 4.5h from last known well and no contraindications, can consider Alteplase (rt-PA).
Review inclusion/Exclusion Criteria for IV tPA – Prior to infusion, ensure BP<180/105 mmHg.

Obtain verbal consent when possible
If within 6h from last known well, has LVO in MCA or ICA, and walks unassisted, can consider endovascular thrombectomy therapy.
If within 6 to 24 hours, is independent at baseline, has LVO in MCA or ICA and has NIHSS>6, can consider endovascular thrombectomy therapy if CT Perfusion is positive.

Role of Interventional Stroke (if available in your region, may require transfer):
Inclusion criteria: NIHSS 6 or more, able to walk unassisted*, LVO in MCA or ICA.
Exclusion criteria: Life expectancy <6 months, technically implausible, >1/3 MCA territory involved
*If beyond 6h, patient needs to be fully independent on ADLs to be considered.

Complications of tPA

1. Bleeding after tPA
Sometimes after administration of tPA, you can get Intracranial Hemorrhage or systemic bleeding AFTER thrombolysis.
If patient worsens clinically during infusion, stop IV pump, obtain stat repeat plain CT head.
Obtain: INR, PTT, platelets and fibrinogen levels, type and cross match.
Administer: Fibrinogen concentrate and Tranexamic Acid 1g IV over 10 min. Can repeat if bleeding continues. Neurosurgery consultation if ICH. Thrombosis consultation.

2. Angioedema
tPA induced angioedema is idiopathic. If patient develops signs of angioedema (e.g. lip swelling, tongue swelling),

  1. Stop tPA
  2. Assess for intubation, if advancing quickly, CALL FOR HELP from ENT and/or Anesthesia. Sometimes it may be best for the patient to be managed in the OR, if a surgical airway is needed (due to recent administration of tPA).
  3. Methylprednisolone 125mg IV x 1
  4. Histamine blockade: Diphenhydramine 50mg IV x1 plus one of (ranitidine 50mg IV or famotidine 20mg IV x 1)
  5. If further angioedema, consider treating as anaphylaxis including: Epinephrine 0.5 mg IM x 1.

Recommended reading, videos, and podcasts

The following is part of the CanadiEM Frontline Primer. An introduction to the primer can be found here. To return to the Primer content overview click here.

This post was edited by Dr. Teresa Chan MD FRCPC MHPE DRCPSC. This post was copyedited and uploaded by Evan Formosa.

References

  1. 1.
    Boulanger J, Lindsay M, Gubitz G, et al. Canadian Stroke Best Practice Recommendations for Acute Stroke Management: Prehospital, Emergency Department, and Acute Inpatient Stroke Care, 6th Edition, Update 2018. International Journal of Stroke. July 2018:949-984. doi:10.1177/1747493018786616
  2. 2.
    Powers WJ, Rabinstein AA, Ackerson T, et al. Guidelines for the Early Management of Patients With Acute Ischemic Stroke: 2019 Update to the 2018 Guidelines for the Early Management of Acute Ischemic Stroke: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association. Stroke. December 2019. doi:10.1161/str.0000000000000211

Luciana Catanese

Vascular Neurologist, Researcher #PHRI, Medical Educator #McMasterU, Associate Editor #StrokeJournal. Assistant Professor of Medicine (Neurology). McMaster University.

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Demetrios Sahlas

Dr. Sahlas is the MG DeGroote Professor in Stroke Management, Department of Medicine, Faculty of Health Sciences, McMaster University.He is also the Program Director for the Adult Neurology Residency Training Program at McMaster University.

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