USMLE Prep - Medical Reference Library

Acute Ischemic Stroke — Door‑to‑Needle, Door‑to‑Groin, and Post‑Reperfusion Care

System: Neurology • Reviewed: Sep 1, 2025 • Step 1Step 2Step 3

Synopsis:

Rapid triage by last‑known‑well and stroke severity, non‑contrast CT to exclude hemorrhage, CTA for LVO, IV alteplase within 4.5 h when eligible, and mechanical thrombectomy up to 24 h in selected patients; strict BP and neuro monitoring after reperfusion.

Key Points

  • Use the highest‑yield diagnostic test early; do not let testing delay time‑critical therapy.
  • Set objective targets (hemodynamic, neurologic, respiratory) and reassess frequently.
  • Plan definitive source control or reperfusion when indicated; document follow‑up and patient education.

Algorithm

  1. Pre‑arrival activation; record last‑known‑well, NIHSS on arrival; POC glucose.
  2. Immediate non‑contrast CT; if no hemorrhage and eligible → IV alteplase ≤4.5 h.
  3. Parallel CTA for LVO; activate thrombectomy team when LVO suspected.
  4. Extended window (6–24 h) → select with perfusion imaging per DAWN/DEFUSE‑3 criteria; proceed to MT when eligible.
  5. Manage BP (pre‑tPA <185/110; post‑tPA ≤180/105); admit to ICU/stroke unit for 24 h monitoring.
  6. Repeat imaging at 24 h; start antithrombotic per protocol; secondary prevention workup (AFib, carotid, lipids).

Clinical Synopsis & Reasoning

Rapid triage by last‑known‑well and stroke severity, non‑contrast CT to exclude hemorrhage, CTA for LVO, IV alteplase within 4.5 h when eligible, and mechanical thrombectomy up to 24 h in selected patients; strict BP and neuro monitoring after reperfusion.


Treatment Strategy & Disposition

Stabilize ABCs. Initiate guideline‑concordant first‑line therapy with precise dosing and continuous monitoring. Escalate to advanced/procedural interventions based on explicit failure criteria. Define ICU, step‑down, and ward disposition triggers; involve specialty teams early.


Epidemiology / Risk Factors

  • Risk varies by comorbidity and precipitants; see citations for condition‑specific data.

Investigations

TestRole / RationaleTypical FindingsNotes
Non‑contrast head CTExclude hemorrhageNo bleed in AISDo not delay if window narrow
CTA head/neck ± CTP/MR perfusionLVO selectionTarget occlusion/penumbraFor extended‑window MT selection
Glucose, INR/plateletsEligibility checksAbnormalities may preclude lyticsPoint‑of‑care when possible

Pharmacology

Medication/InterventionMechanismOnsetRole in TherapyLimitations
Alteplase (tPA) 0.9 mg/kg (max 90 mg)ThrombolyticMinutesIV thrombolysis ≤4.5 h (10% bolus, rest over 60 min)Standard contraindications; post‑tPA BP ≤180/105
Nicardipine/clevidipine infusionAntihypertensiveMinutesPre/post‑reperfusion BP controlAvoid hypotension
AspirinAntiplateletHoursStart 24 h post‑tPA if no bleedEarlier if no tPA and no hemorrhage

Prognosis / Complications

  • Outcome depends on timeliness of diagnosis and definitive therapy; monitor for complications.

Patient Education / Counseling

  • Provide red‑flag education, adherence guidance, and explicit return precautions; arrange timely specialty follow‑up.

References

  1. 2019 AHA/ASA Guideline Update for the Early Management of AIS — Link
  2. AHA/ASA 2019 AIS Slide Deck (Door‑to‑Needle/Thrombectomy) — Link