ASC Evidence-Based Stroke Protocols 2 — Questions and Answers
Question 1: According to AHA/ASA guidelines, what is the maximum acceptable door-to-CT time for acute ischemic stroke patients?
- 25 minutes (Correct answer)
- 45 minutes
- 60 minutes
- 90 minutes
Correct answer: 25 minutes
AHA/ASA guidelines recommend a door-to-CT completion time of ≤25 minutes for acute ischemic stroke patients.
Question 2: Which imaging modality is considered the gold standard for detecting acute ischemic stroke within the first 24 hours?
- Non-contrast CT
- MRI with DWI sequence (Correct answer)
- CT angiography
- Transcranial Doppler
Correct answer: MRI with DWI sequence
MRI with diffusion-weighted imaging (DWI) is the gold standard for detecting acute ischemic stroke, showing restricted diffusion within minutes of onset.
Question 3: In the DAWN and DEFUSE 3 trials, patient selection for late-window thrombectomy (6–24 hours) was primarily based on:
- NIHSS score alone
- Age and comorbidities
- Perfusion imaging mismatch (clinical-core or perfusion-core) (Correct answer)
- Time of symptom onset only
Correct answer: Perfusion imaging mismatch (clinical-core or perfusion-core)
Both DAWN and DEFUSE 3 used perfusion imaging mismatch criteria (clinical-core or perfusion-core) to identify patients with salvageable penumbra beyond 6 hours.
Question 4: A patient presents with acute ischemic stroke and BP of 195/105 mmHg. Per AHA guidelines, when is antihypertensive treatment indicated before IV tPA administration?
- BP > 140/90 mmHg
- BP > 160/90 mmHg
- BP ≥ 185/110 mmHg (Correct answer)
- BP > 200/120 mmHg
Correct answer: BP ≥ 185/110 mmHg
AHA guidelines require blood pressure to be lowered to <185/110 mmHg before administering IV alteplase to reduce hemorrhagic transformation risk.
Question 5: Which of the following represents the correct alteplase dosing for acute ischemic stroke?
- 0.6 mg/kg IV, max 60 mg
- 0.9 mg/kg IV, max 90 mg (Correct answer)
- 1.0 mg/kg IV, max 100 mg
- 0.9 mg/kg IV, max 60 mg
Correct answer: 0.9 mg/kg IV, max 90 mg
The standard alteplase dose is 0.9 mg/kg (maximum 90 mg total), with 10% given as a bolus and the remaining 90% infused over 60 minutes.
Question 6: Per evidence-based stroke protocols, after successful IV tPA administration, when should the first post-thrombolysis CT scan be performed?
- At 1 hour post-infusion
- At 24 hours post-infusion (Correct answer)
- At 48 hours post-infusion
- Only if neurological deterioration occurs
Correct answer: At 24 hours post-infusion
Standard protocols recommend a follow-up CT scan at 24 hours post-tPA to evaluate for hemorrhagic transformation before initiating antiplatelet or anticoagulant therapy.
Question 7: The ASPECTS (Alberta Stroke Program Early CT Score) is used to:
- Predict 90-day functional outcome based on NIHSS
- Quantify early ischemic changes on non-contrast CT to guide reperfusion therapy decisions (Correct answer)
- Grade hemorrhagic transformation severity
- Measure infarct core volume on MRI DWI
Correct answer: Quantify early ischemic changes on non-contrast CT to guide reperfusion therapy decisions
ASPECTS is a 10-point scoring system that quantifies early ischemic changes on non-contrast CT, with scores ≤6 generally indicating poor thrombectomy candidacy.
ASC Evidence-Based Stroke Protocols 2
According to AHA/ASA guidelines, what is the maximum acceptable door-to-CT time for acute ischemic stroke patients?