Stroke / TIA

Category: Medical Sources: raw/protocols/nm-sop-guidelines-treatment-2022.pdf Last updated: 2026-05-06 Sources: raw/protocols/nm-sop-guidelines-treatment-2022.pdf; UCLA EMT Ultimate Study Guide (2026)

Overview

A stroke (cerebrovascular accident, CVA) is caused by either ischemia (clot blocking cerebral blood flow — 85% of cases) or hemorrhage (rupture of a cerebral blood vessel). Transient ischemic attack (TIA) presents identically but resolves within 24 hours (usually minutes) without infarction. Both require urgent evaluation.

Prehospital priorities: recognize stroke using a validated tool (Cincinnati, FAST), establish "last known well" time precisely, transport to a Stroke Center with advance notification. The time window for IV thrombolytics (tPA) is typically 3–4.5 hours from symptom onset — early notification is critical. Large vessel occlusion (LVO) strokes may benefit from mechanical thrombectomy with a wider time window.

Key Points

• Time is brain — every minute of stroke = 1.9 million neurons lost
• "Last known well" (last time patient was at their neurological baseline) is THE most important history element — not just symptom onset time
• Do NOT treat hypertension in the prehospital setting for stroke — BP elevation may be compensatory
• Do NOT give aspirin for suspected stroke — hemorrhagic stroke contraindicates anticoagulants
• Hypoglycemia can mimic stroke — always check blood glucose
• LVO scales (RACE, C-STAT, LAMS) identify patients who may benefit from thrombectomy — NM protocols direct use of these
• Bypass non-stroke-capable facility to transport to Stroke Center when possible

Assessment Relevance

Stroke screening tools:

Cincinnati Prehospital Stroke Scale (3 items) — see cincinnati-stroke-scale for full testing protocol, sensitivity/specificity, and last known well guidance: - Facial droop: ask patient to smile — one side droops - Arm drift: arms outstretched eyes closed 10 seconds — one arm drifts down - Speech: "You can't teach an old dog new tricks" — slurred, wrong words, or mute - Any ONE abnormal = 72% probability of stroke

FAST mnemonic: Face, Arms, Speech, Time

LVO scales (identify large vessel occlusion for thrombectomy candidacy): - RACE: facial palsy, arm motor, leg motor, head/gaze deviation, agnosia/aphasia - Higher score = higher likelihood of LVO requiring mechanical thrombectomy

History (history-taking): - Last known well — exact time patient was last at neurological baseline - Symptom onset timeline - Blood glucose check — mandatory - Blood thinner medications (especially NOACs, warfarin, clopidogrel — affects tPA eligibility) - Prior stroke/TIA history - Headache (sudden severe "thunderclap" headache = hemorrhagic stroke until proven otherwise)

Physical exam (secondary-assessment): - Neuro: LOC (AVPU), pupil equality, focal deficits (unilateral weakness, facial droop) - Vital signs: BP (typically elevated), pulse, SpO2 - Blood glucose: hypoglycemia can mimic stroke

Procedures

1. Scene size-up (scene-size-up): medical NOI; consider fall trauma if patient was found down
2. Primary assessment (primary-assessment): airway (LOC-impaired patients may not protect airway), breathing (SpO2), circulation; determine priority
3. Perform Cincinnati or FAST stroke screen
4. Establish "last known well" time — question family/bystanders aggressively
5. Perform LVO scale if trained (RACE, C-STAT, LAMS)
6. Check blood glucose — treat hypoglycemia if present
7. Apply oxygen ONLY if SpO2 <94%; titrate to maintain 94–99%
8. Transport to Stroke Center with advance notification — do NOT delay on scene
9. Reassessment en route (reassessment) — serial neuro checks; watch for airway compromise

NM Protocol Notes

From NM EMS Treatment Guidelines (2022):

EMT-B scope: - Provide oxygen only if SpO2 <94%; titrate to maintain >94% — do not hyperoxidize - Perform serial prehospital stroke assessments: Cincinnati, Los Angeles, or FAST scales - Perform LVO scale: RACE, C-STAT, or LAMS - Establish timeline: last known well, last seen at baseline, blood glucose level - Document blood thinner usage (especially beyond aspirin/clopidogrel — affects hospital treatment options) - If seizure activity present, refer to Seizure guideline - Transport to nearest Stroke Center or acute stroke-ready hospital; early notification is essential - Consider bypassing non-stroke-capable facility - Consider ALS intercept or aeromedical resources for symptomatic stroke - Do NOT treat hypertension in the prehospital setting - IV access (EMT-I/P only); avoid multiple IV attempts — do not delay transport for IV access

NM note on destination: Patients with stroke signs should be transported to the nearest stroke center or, if unavailable, to an acute stroke-ready hospital. The time savings from bypassing a non-capable facility and the hospital's preparation time are both critical factors.

NREMT Relevance

High-frequency NREMT topic: - Cincinnati Prehospital Stroke Scale components and interpretation (any ONE positive = suspect stroke) - "Last known well" vs. "symptom onset" — distinguish these; both are asked on NREMT - Do NOT give aspirin for stroke (hemorrhagic risk) - Do NOT treat hypertension prehospital for stroke - Hypoglycemia mimics stroke — check BGL is a standard NREMT question - Transport destination: Stroke Center, with advance notification - "Thunderclap headache" = hemorrhagic stroke red flag

NREMT Differentiators

Stroke Type Comparison

Condition	Key Finding	Onset	Treatment	KEY DIFFERENTIATOR
Ischemic Stroke	Facial droop, arm drift, speech (CPSS) + sudden severe headache, unilateral weakness	Sudden	O2, BGL check, semi-Fowler's, rapid transport, pre-notify	Clot occludes cerebral artery — tPA eligible 3–4.5 hours. Both ischemic and hemorrhagic LOOK THE SAME in field.
Hemorrhagic Stroke	"WORST HEADACHE OF LIFE" + rapid neuro deterioration + vomiting + very high BP + rapid ↓ LOC	Sudden maximal	Airway priority, O2, HOB 30°, rapid transport — CT urgent	Ruptured cerebral vessel. Do NOT give aspirin or tPA — can be lethal. CT confirms type.
TIA	Stroke symptoms that FULLY RESOLVE within 24 hours (usually <1 hour)	Sudden, then clears	Treat EXACTLY like stroke; note onset AND resolution time	Temporary occlusion — "warning stroke." 35% will have full stroke within 3 months. NEVER say "you're fine now."
Syncope	Brief LOC with IMMEDIATE full recovery when supine	Brief	Supine, legs elevated, O2, BGL, ECG monitoring	No neuro deficit, no postictal state, no speech issues. Rule out cardiac cause.

KEY DIFFERENTIATOR: Both ischemic and hemorrhagic look identical in field. DO NOT give aspirin to any stroke patient — it worsens hemorrhagic. Transport to stroke center either way.

NREMT TIP: Time is brain. 35% of thrombotic strokes are preceded by a TIA. Pre-notification of the stroke center is the #1 most impactful EMT intervention — saves 15–20 minutes of hospital activation time.

tPA Time Windows

• 0–3 hours: good outcomes
• 3–4.5 hours: favorable (borderline)

• 4.5 hours: risks outweigh benefits

"Last known well" = last time patient was at their neurological baseline — NOT the time symptoms were discovered. This is the clock that starts the tPA window.

Do NOT in Stroke

• Do NOT give aspirin (hemorrhagic risk)
• Do NOT treat hypertension prehospital (may be compensatory)
• Do NOT delay transport for IV access or additional assessment

Related

• cincinnati-stroke-scale — full testing protocol for facial droop, arm drift, speech; FAST comparison; last known well vs. onset time
• history-taking — SAMPLE and OPQRST; "last known well" and medication history are critical
• secondary-assessment — neuro assessment, pupils, focal deficits, blood glucose
• primary-assessment — airway protection in low-LOC stroke patients
• diabetic-emergencies — hypoglycemia mimics stroke; must be ruled out
• seizure — post-stroke seizure management
• geriatric — atypical stroke presentations in elderly; subtle gait change or confusion may be the only sign

Sources

• raw/protocols/nm-sop-guidelines-treatment-2022.pdf — Suspected Stroke/TIA protocol (p. 45)