What are the different levels of severity when a medical team calls a code stroke alert?

Code Stroke Alert Levels

Code stroke alerts are primarily categorized using the Canadian Triage Acuity Scale (CTAS), with most suspected stroke patients triaged as CTAS Level 2, while those with compromised airway, breathing, or cardiovascular function are escalated to CTAS Level 1. 1

Primary Triage Classification System

The evidence-based framework for code stroke alerts uses a two-tiered approach:

CTAS Level 1 (Resuscitation)

• Reserved for stroke patients with compromised airway, breathing, or cardiovascular function 1
• These patients require immediate physician assessment (target: within 0 minutes) 2
• Represents the most critical stroke presentations requiring simultaneous resuscitation and stroke management 1

CTAS Level 2 (Emergent)

• Applied to most suspected stroke patients without cardiopulmonary compromise 1
• Target time-to-provider assessment: within 10-15 minutes 2
• This represents the standard code stroke activation level for typical acute stroke presentations 1

Pediatric Stroke Alert Modifications

For pediatric patients, the Pediatric Canadian Triage Acuity Scale (P-CTAS) mirrors the adult system:

• P-CTAS Level 1: Pediatric strokes with severe symptoms or compromised airway, breathing, or cardiovascular function 1
• P-CTAS Level 2: Most pediatric suspected stroke cases 1

Additional Severity Stratification Factors

Beyond the CTAS triage level, code stroke alerts incorporate several clinical parameters that influence urgency and destination:

Time-Based Eligibility Categories

• Hyperacute window (≤4.5 hours): Patients potentially eligible for intravenous alteplase 1
• Extended window (up to 24 hours): Highly selected patients for endovascular therapy based on advanced neurovascular imaging 1
• The time from symptom onset fundamentally determines treatment eligibility and transport destination 1

Stroke Severity Assessment

• The National Institutes of Health Stroke Scale (NIHSS) provides granular severity assessment (0-42 scale) 1
• NIHSS <5 indicates mild stroke, while NIHSS >20 indicates large stroke 1
• Moderate strokes (NIHSS 9-15) show the strongest time-dependent benefit from treatment within 120 minutes 3
• Severe strokes may indicate large vessel occlusion requiring direct transport to comprehensive stroke centers 1

Large Vessel Occlusion Screening

• Patients with suspected large vessel occlusion based on prehospital screening tools may warrant direct transport to endovascular-capable centers 1
• This represents a functional "higher alert level" in terms of destination selection and resource mobilization 1

Critical Information Required for Alert Activation

When activating a code stroke, EMS must communicate specific details to enable appropriate triage:

• Time last known well (most critical parameter) 1
• Glasgow Coma Scale score 1
• CTAS or P-CTAS level 1
• Presenting stroke signs and symptoms 1
• Current antithrombotic medication use 1
• Patient age and expected arrival time 1

Common Pitfalls in Alert Level Assignment

Avoid delaying code stroke activation while waiting for CT imaging - studies demonstrate that obtaining CT before alerting the stroke team significantly delays door-to-needle times 4. The stroke alert should be activated immediately upon recognition, with imaging occurring as part of the coordinated response 5.

Do not undertriage based solely on mild symptoms - nurses activate in-hospital stroke alerts with similar accuracy to physicians (62.7% vs 58.8%) but do so significantly earlier (median 2 hours vs 4.9 hours from symptom onset) 6. Early recognition and alert activation, even for mild presentations, is critical for maintaining treatment windows 7.

Recognize that in-hospital strokes face systematic delays compared to ED arrivals, making prompt alert activation even more crucial for hospitalized patients who develop acute neurological changes 7.