Algorithmic Approach to Stroke: Diagnosis and Management
Immediate Recognition and Activation (Minutes 0-10)
All patients with suspected stroke require immediate emergency medical services (EMS) activation and transport to a stroke-capable hospital, as this is the single most critical determinant of outcome. 1, 2
Prehospital Recognition
- Use FAST screening tool (Face drooping, Arm weakness, Speech difficulty, Time to call 911) for rapid stroke identification 2
- EMS personnel should use validated stroke screening tools during on-scene assessment 1
- Target on-scene time ≤20 minutes for patients within the 4.5-hour treatment window 1
- Obtain critical information: exact time of symptom onset (or time last known well), current medications (especially anticoagulants), and baseline functional status 1
- Measure blood glucose in the field to rule out hypoglycemia as a stroke mimic 1
- Transport directly to designated stroke centers, bypassing non-stroke-capable hospitals 1
Common Pitfall
Do not delay transport for extensive on-scene evaluation—the goal is "recognize and mobilize" 1
Emergency Department Evaluation (Minutes 10-25)
Triage stroke patients with the same priority as acute myocardial infarction or major trauma, regardless of symptom severity. 1, 3
Immediate Assessment (First 10 Minutes)
Determine exact time of symptom onset (defined as when patient was last at baseline/symptom-free) 3
- This is the single most critical piece of information for treatment eligibility 1
Rapid neurological examination using standardized scale 1
Vital signs monitoring 1
- Heart rate and rhythm
- Blood pressure (both arms)
- Temperature
- Oxygen saturation
Initial Investigations (Parallel to Clinical Assessment)
Do NOT delay imaging or treatment decisions while awaiting these results unless clinically indicated 1
- Blood glucose (immediate—to rule out hypoglycemia) 1
- CBC, electrolytes, creatinine, eGFR 1
- Coagulation studies (INR, aPTT)—required only if patient is on warfarin 1
- Troponin 1
- ECG—defer until after thrombolysis decision unless patient is hemodynamically unstable 1
- Chest X-ray—defer until after acute treatment decision unless acute cardiopulmonary disease suspected 1
Critical Caveat: "Neurons Over Nephrons"
Do not delay CT angiography (CTA) while awaiting renal function results in patients with disabling stroke symptoms, even with known renal impairment—the benefit of identifying candidates for acute treatment outweighs nephrotoxicity risk 1
Neuroimaging (Target: Within 25 Minutes of Arrival)
All patients with suspected stroke must have urgent brain imaging (CT or MRI) within 24 hours, but ideally within 25 minutes of ED arrival for treatment-eligible patients. 2, 3
Imaging Protocol
Non-contrast CT head (first-line) 2
- Differentiates ischemic stroke from hemorrhagic stroke
- Rules out stroke mimics (tumor, abscess)
- Identifies early ischemic changes
CT angiography (CTA) for patients with disabling symptoms 1
- Identifies large vessel occlusions eligible for thrombectomy
- Should not be delayed by awaiting renal function in most cases 1
CT perfusion (if available and within treatment window) 2
- Identifies salvageable brain tissue
- Guides extended window treatment decisions (6-24 hours)
Repeat Imaging Indications
Urgent repeat CT/MRI if patient's neurological condition deteriorates 2
Diagnosis: Stroke vs. Stroke Mimics
Confirm Ischemic Stroke When:
- Abrupt onset of focal neurological deficits 5
- Symptoms present on awakening 5
- Imaging shows no hemorrhage 2
- Deficits correspond to vascular territory 1
Rule Out Stroke Mimics:
- Hypoglycemia: Check glucose immediately (most common mimic) 1
- Seizure: History of seizures, witnessed seizure activity, postictal state 1
- Migraine with aura: History of similar events, preceding aura, headache 1
- Conversion disorder: Inconsistent examination, non-anatomic distribution 1
- Hypertensive encephalopathy: Severe hypertension, headache, delirium 1
Acute Treatment Decision Algorithm
For Ischemic Stroke Within 4.5 Hours of Symptom Onset:
Step 1: Determine IV tPA Eligibility 2, 3
Administer IV alteplase (0.9 mg/kg, max 90 mg) if:
Do NOT wait for blood work results unless:
Blood pressure requirements for tPA:
- Must lower BP to <185/110 mmHg before tPA administration 3
- Maintain BP <180/105 mmHg for 24 hours after tPA 4, 3
Step 2: Assess for Mechanical Thrombectomy Eligibility 2, 3
Consider thrombectomy if:
- Large vessel occlusion identified on CTA 2
- Within 6-24 hours of symptom onset (based on imaging criteria) 2, 3
- Significant salvageable brain tissue on perfusion imaging 2
Thrombectomy can be performed:
- Alone (if outside tPA window or contraindications exist)
- In combination with tPA (within 4.5-hour window) 2
Blood Pressure Management Algorithm
For Patients NOT Receiving Thrombolysis: 4, 3
- Do NOT treat blood pressure unless:
- Systolic BP >220 mmHg OR
- Diastolic BP >120 mmHg
- Rationale: Elevated BP may maintain cerebral perfusion to ischemic penumbra 1
For Patients Receiving tPA: 4, 3
- Before tPA: Lower BP to <185/110 mmHg
- After tPA: Maintain BP <180/105 mmHg for 24 hours
- Monitor BP every 15 minutes for 2 hours, then every 30 minutes for 6 hours, then hourly for 16 hours 4
Hemorrhagic Stroke Management
If CT Shows Hemorrhage:
Intracerebral Hemorrhage (ICH):
- Immediate neurosurgical consultation 1
- Reverse anticoagulation if applicable 2
- Blood pressure control (target systolic 140-180 mmHg) 2
- Monitor for increased intracranial pressure 2
Subarachnoid Hemorrhage (SAH):
- Presents with sudden severe "thunderclap" headache 1
- If CT negative but high suspicion: perform lumbar puncture to check for xanthochromia 1, 6
- Immediate neurosurgical consultation 2
- Secure aneurysm (coiling or clipping) 2
Acute Stroke Unit Care (First 24-72 Hours)
All stroke patients must be admitted to a geographically defined stroke unit with specialized interdisciplinary staff—this intervention has mortality benefit equivalent to tPA administration. 2, 3
Monitoring Protocol (First 24 Hours): 2, 4
- Neurological status: Every 15 minutes for 2 hours (if received tPA), then hourly 2
- Vital signs: Every 15-30 minutes initially, then every 4 hours 4
- Temperature: Every 4 hours for 3 days; treat if >37.5°C (99.5°F) with acetaminophen 4
- Blood glucose: Every 4 hours for 3 days; treat if >180 mg/dL (10 mmol/L) with insulin 4
- Oxygen saturation: Continuous monitoring; supplement only if <94% 4
Swallowing Assessment (Within 24 Hours): 2, 4, 3
Perform validated swallowing screening before giving any food, fluids, or oral medications 2, 4
- If failed: keep NPO, consider NG tube, formal speech-language pathology evaluation 3
- Critical pitfall: Aspiration pneumonia is preventable with proper screening 4
Prevention of Complications: 2, 4
- DVT prophylaxis: Early mobilization, sequential compression devices 4
- Pressure ulcer prevention: Frequent turning, alternating pressure mattresses 2
- Urinary retention screening: Bladder scan for post-void residual within 72 hours 4
- Avoid indwelling catheters unless absolutely necessary 4
- Fall prevention protocols during transfers and toileting 4
Early Rehabilitation (Begin Within 48 Hours)
Initial rehabilitation assessment by specialized professionals must occur within 48 hours of admission, with therapy beginning as soon as medically stable. 2, 3
Rehabilitation Components: 2, 4
- Physical therapy: Early mobilization, gait training, strengthening 2
- Occupational therapy: ADL training, adaptive equipment 2
- Speech-language pathology: Dysphagia management, aphasia therapy 2
- Daily stretching of hemiplegic limbs to prevent contractures 4
- Position hemiplegic shoulder in maximum external rotation for 30 minutes daily 4
Secondary Prevention (Initiate During Hospitalization)
Antiplatelet Therapy:
Start aspirin 160-300 mg daily within 48 hours of ischemic stroke onset (if not receiving thrombolysis) 2, 3
Do NOT use anticoagulation (heparin, LMWH) routinely—increases bleeding risk without benefit 4, 7
Carotid Evaluation and Intervention: 2, 3
- Urgent carotid duplex ultrasound for patients with carotid territory symptoms who are surgical candidates 4
- Carotid endarterectomy recommended if:
- Consider endarterectomy for stenosis 50-69% in select patients 2
Cardiac Evaluation: 1
- ECG: Identify atrial fibrillation 1
- Prolonged cardiac monitoring (up to 30 days) if cardioembolic mechanism suspected but initial ECG normal 1
- Echocardiogram if stroke mechanism unidentified 1
Risk Factor Management: 3
- Hypertension control (target <140/90 mmHg after acute phase)
- Diabetes management
- Lipid management (statin therapy)
- Smoking cessation
- Lifestyle modifications
Disposition and Follow-Up
Discharge Criteria:
- Medically stable 2
- Swallowing safety established 2
- Secondary prevention initiated 1
- Rehabilitation plan in place 2
- Patient/family education completed 4
Discharge Planning: 4
- Timely transfer of information to outpatient physician 4
- Clear follow-up appointments arranged 4
- Education on stroke warning signs and when to call 911 4
- Medication reconciliation and adherence plan 2
Ongoing Rehabilitation: 2
- Continue in stroke rehabilitation unit or general rehabilitation unit if needed 2
- Community-based rehabilitation equally effective (outpatient, day hospital, home-based) 2
- Offer to all stroke patients as clinically indicated 2
Key Time Targets Summary
| Milestone | Target Time |
|---|---|
| EMS on-scene time | ≤20 minutes [1] |
| Door to imaging | ≤25 minutes [1] |
| Door to tPA decision | ≤60 minutes [1] |
| Swallowing screen | Within 24 hours [2,4] |
| Rehabilitation assessment | Within 48 hours [2,3] |
| Carotid endarterectomy (if indicated) | Within 2 weeks [2] |
Critical Pitfalls to Avoid
- Delaying imaging while awaiting blood work—only INR is required before tPA in anticoagulated patients 1
- Withholding CTA due to renal concerns—"neurons over nephrons" principle applies 1
- Treating elevated blood pressure too aggressively in non-thrombolysis candidates 4, 3
- Missing swallowing dysfunction—screen before any oral intake 2, 4
- Discharging TIA patients without full evaluation—30% stroke risk after TIA 1, 8
- Delaying carotid endarterectomy—benefit greatest when performed within 2 weeks 2
- Using routine anticoagulation for acute ischemic stroke—increases bleeding without benefit 4, 7