Acute Ischemic Stroke - Dr. Tesoro (FINAL)

What are the 2 consequences of stroke?

- Ischemia (reversible)

- Infarction (irreversible cell death)

Neurological symptoms from a stroke are typically caused by _____ CNS infarction.

Focal

What is a brief stroke episode with return to baseline?

Transient ischemic attack

What are 2 stroke classifications?

- Ischemic (most popular): blood clot blocks flow to an area of the brain

- Hemorrhagic (less popular): rupture and bleeding

What are signs and symptoms of a stroke?

- Sudden weakness, dizziness, or difficulty walking

- Sudden confusion or difficulty speaking

- Sudden changes in vision

- Sudden facial droop or numbness

- Sudden severe headaches

What is a patient friendly acronym to remember signs and symptoms of a stroke?

BEFAST

- Balance

- Eyes

- Face

- Arms

- Speech

- Time

What is a transient ischemic attack?

- Brief episode of neurological dysfunction caused by a focal disturbance of brain or retinal ischemia with clinical symptoms typically lasting < 1 hour without evidence of infarction

- Major determinant of future stroke in the next few days

- Similar approach to stroke --> seek medical attention

What are the goals of therapy?

- Restore blood flow to ischemic tissue

- Reverse neurological deficit

- Limit area of ischemia

- Salvage the penumbra

- Prevent complications

What are does initial stroke management look like?

- Stabilize the airway, breathing, circulation

- Cardiac monitoring

- IV access

- O2

- Assess for hypoglycemia

- History --> when was "last known well"

What diagnostic studies should be run when patient first presents with stroke symptoms?

IMAGING

- CT to rule out ICH

TESTS

- ECG

- EEG

LABS

- Blood glucose (make sure patient is not hypoglycemic i.e. < 60 mg/dL)

- Electrolytes

- Renal function

- INR/ PT/ PTT

- LFT

- Pregnancy

- Toxicology screen

- Blood alcohol level

What is the NIH Stroke Sale (NIHSS)?

- Standardized, validated assessment of the severity of stroke

- 0 = NORMAL

- > 20 = SEVERE STROKE --> poor prognosis at this point

What is the ABCD2 Score? What are the components of the test?

Tool to assess stroke risk after suffering TIA

Predictors include:

--> Age > 60 (1 POINT)

--> Blood pressure > 140/90 (1 POINT)

--> Clinical features (1 POINT for speech difficulty without weakness, 2 POINTS for unilateral weakness)

--> Duration (0 POINTS for < 10 minutes, 1 POINT for 10 - 59 minutes, 2 POINTS FOR > 60 minutes)

--> Diabetes (1 POINT for diabetes)

How do you classify low vs. medium vs. high risk using the ABCD2 Score?

Low risk = 0 - 3

Medium risk = 4 - 5

High risk = 6 - 7

Patient presented < 4.5 hours from onset of symptoms. Can we treat with thrombolytics?

- Obtain non-contrast CT first

- If no evidence of hemorrhage, go ahead

Patient presented 4.5 - 9 hours from onset of symptoms. Can we treat with thrombolytics?

- Obtain CT perfusion scan

- If no evidence of hemorrhage AND penumbra > infarct core, go ahead

Patient presented 9 - 24 hours from onset of symptoms. Can we treat with thrombolytics?

- Obtain MRI perfusion scan

- If no evidence of hemorrhage AND penumbra > infarct core, go ahead

If a stroke patient has evidence of large vessel occlusion, what should they undergo?

- Mechanical thrombectomy

- However, if this is not possible, thrombolytic therapy is reasonable if pt is eligible

- Patients are able to receive both if eligible as well

What are the absolute contraindications to tPA?

- CT w/ extensive hypodensity (i.e. massive stroke, pt is high bleed risk)

- Acute intracranial hemorrhage

- Moderate to severe TBI within 14 days

- Neurosurgery within 14 days

- Acute spinal cord injury within 3 months

- Intra-axial neoplasm

- Infective endocarditis

- Severe coagulopathy (platelets < 100,000, INR > 1.7, aPTT > 40 sec, PT > 15 sec)

- Aortic arch dissection

- Amyloid-related imaging abnormalities

Is antiplatelet therapy a contraindication to tPA?

No!

What are the 2 thrombolytic drug options?

ALTEPLASE (Activase)

- Weight based dosing: 0.9 mg/kg IV (max dose 90 mg)

- Administration: 10% over 1 minute, remainder over 1 hour

- Half life of 5 minutes (SHORT)

- Do not administer anti-thrombotics or anticoagulants for the next 24 hours

- Do not place a bladder catheter, NG tube, arterial catheter for 24 hours (high risk of bleeding)

TENECTEPLASE (TNKase)

- More thrombin specific than alteplase!

- Half life of 90 - 130 minutes (LONG)

- Dose: 0.25 mg/kg IV bolus (max dose 25 mg)

- Do not administer anti-thrombotics or anticoagulants for the next 24 hours

- Do not place a bladder catheter, NG tube, arterial catheter for 24 hours (high risk of bleeding)

How do we treat blood pressure while patient is having AIS + receiving tPA?

Maintain BP < 180/ 105 --> permissive hypertension to optimize perfusion to the brain

Blood pressure must be < ______ to initiate tPA.

185/ 110

Once tPA has been initiated, what are some monitoring parameters?

NEUROLOGIC ASSESSMENT

- Every 15 minutes x 1 hour

- Every 30 minutes x 6 hours

- Every hour till 24 hours have passed

BLOOD PRESSURE (maintain < 180 /105)

- Every 15 minutes x 2 hours

- Every 30 minutes x 6 hours

- Every hour till 24 hours have passed

CT/MRI

- After 24H

- Make sure this is complete before starting antithrombotic or anticoagulant

What should you do if you suspect your patient have developed an intracranial hemorrhage while on tPA?

- Signs: Sudden worsening of neurological exam, headache, nausea/ vomiting, acute HTN

- STOP the tPA administration

- STAT non-contrast CT scan to look for evidence of hemorrhage

- Get labs (CBC, PT, INR, PTT, platelets, fibrinogen)

- Cryoprecipitate to keep fibrinogen > 150 mg/dL

- Administer antifibrinolytics such as tranexamic acid or aminocaproic acid

- Neuro + heme consults

What are risk factors for ICH post tPA?

- Not following thrombolytic protocol

- Higher dose of tPA

- Elevated blood glucose

- Poor blood pressure control

- Early ischemic changes on CT

- Advanced age

- Stroke severity

What sever symptom must be monitored for when initiating tPA? Which agent do we see this with? Name 2 risk factors.

Angioedema due to alteplase!

RISK FACTORS

- Prior ACEi use (not a contraindication)

- Insular/ frontal cortex stroke

How do we treat tPA induced angioedema?

- STOP tPA

- HOLD ACEi

STEP 1) Start antihistamines --> Diphenhydramine 50 mg IV AND (famotidine 20 mg IV or ranitidine 50 mg IV)

STEP 2) Start corticosteroids --> Methylprednisolone 125 mg IV OR hydrocortisone 100 mg IV

STEP 3) Start sympathomimetic --> Epinephrine 0.1% 0.3 mL SQ or 0.5 mL by nebulizer

What 3 endovascular procedures are available for stroke patients?

- Mechanical Thrombectomy: removing the clot

- Intra-arterial (IA) thrombolysis

- Cerebral angioplasty

What is Intra-Arterial tPA?

- NOT FDA-approved

- Giving a clot-busting drug directly into the blocked artery in the brain during a catheter-based procedure

- Can be used adjunct to mechanical thrombectomy

What medication should be started within 48 hour of stroke onset?

Aspirin!

If a patient is ineligible for both IVT (IV thrombolytics) and EVT (Endovascular Therapy), what is their last option?

Aspirin!

If the patient has received IVT, how long must we hold ASA?

24 hours after alteplase or tenecteplase

When should you start thrombolytics in eligible patients?

As soon as possible!