In a patient with an NIHSS score of 20 acute ischemic stroke presenting within 4.5 hours and no contraindications, what is the recommended acute treatment?

Acute Ischemic Stroke with NIHSS 20: Recommended Treatment

Administer IV alteplase 0.9 mg/kg (maximum 90 mg) immediately if the patient presents within 4.5 hours of symptom onset and has no contraindications. 1

Treatment Protocol

Immediate IV Alteplase Administration

• Give alteplase 0.9 mg/kg with a maximum dose of 90 mg total, administered as 10% IV bolus over 1 minute, followed by 90% infused over 60 minutes 1, 2
• Treatment should be initiated as quickly as possible because time to treatment is strongly associated with outcomes 1
• Do not delay alteplase for endovascular imaging or transfer if the patient is eligible for IV thrombolysis 1

Critical Pre-Treatment Requirements

Blood pressure management:

• Lower BP to <185/110 mmHg before initiating alteplase using antihypertensive agents 1, 2
• Maintain BP <180/105 mmHg for at least 24 hours after treatment 2

Imaging requirements:

• Non-contrast CT must exclude intracranial hemorrhage 1
• Early ischemic changes should not exceed 1/3 of the MCA territory 1, 2
• Only blood glucose assessment must precede alteplase administration 1

Laboratory requirements:

• Confirm blood glucose >50 mg/dL (>3.3 mmol/L) 1
• Obtain CBC, electrolytes, creatinine, INR, PTT, and troponin, but do not delay treatment for results unless coagulopathy is suspected 1

NIHSS 20 Specific Considerations

An NIHSS score of 20 represents severe stroke, but this does not contraindicate alteplase within 3 hours of onset. 1

• Within 0-3 hours: IV alteplase is indicated for severe stroke symptoms despite increased risk of hemorrhagic transformation, as there is proven clinical benefit 1
• Within 3-4.5 hours: The 2018 AHA/ASA guidelines recommend alteplase for patients with NIHSS ≤25, making your patient with NIHSS 20 eligible 1
• No dose adjustment is needed based on NIHSS score, although severe strokes carry increased hemorrhagic transformation risk 2

Endovascular Therapy Consideration

If the patient has a large vessel occlusion (LVO), proceed with mechanical thrombectomy in addition to IV alteplase—do not wait to evaluate response to alteplase before initiating endovascular evaluation. 1

• Obtain CT angiography to assess for LVO if endovascular therapy is available 1
• Eligible patients should receive IV alteplase even if mechanical thrombectomy is being considered 1
• Do not evaluate responses to IV thrombolysis before proceeding with catheter angiography for mechanical thrombectomy 1

Post-Administration Management

• Avoid antithrombotic therapy (aspirin, anticoagulation) for 24 hours after alteplase administration 1, 2
• Monitor neurological status closely for hemorrhagic transformation 1
• Maintain strict BP control <180/105 mmHg for 24 hours 2

Common Pitfalls to Avoid

Do not withhold alteplase based on stroke severity alone. The evidence shows that severe strokes (high NIHSS) benefit from treatment despite higher hemorrhagic transformation risk. 1 The absolute contraindication in the 3-4.5 hour window is NIHSS >25, not NIHSS 20. 1

Do not delay IV alteplase to obtain vascular imaging or arrange transfer for endovascular therapy. If the patient is eligible for IV thrombolysis, begin treatment immediately and then proceed with additional imaging or transfer. 1 Time is brain—every minute of delay worsens outcomes. 1

Do not wait for all laboratory results before administering alteplase. Only blood glucose must be checked before treatment. 1 Other labs should be obtained but should not delay door-to-needle time.