All EMS presentations
NeurologicClinical presentation

Altered LOC / confusion

A streamlined, differential-led presentation for rapid clinical review.

Clinical snapshot

Twenty-second review

  • Altered consciousness results from diffuse cerebral dysfunction caused by hypoxia, hypoperfusion, glucose disturbance, infection, toxins, seizure, trauma, or focal neurologic disease.
  • Falling GCS, focal deficit, meningism, severe headache, shock, hypoventilation, head trauma, or persistent unexplained change is time-sensitive.
  • Keep intoxication in the differential; overlapping or concurrent illness remains possible.
  • For altered loc / confusion, trends and combinations of findings are more informative than one isolated vital sign.
Differentials

Compare the clinical patterns

The repeated material is grouped inside each possibility. Open only the condition you need.

Serious3 conditions
StrokeTime-sensitive high-risk possibility

HPI

Clarify last known normal; cognitive baseline; gcs and trend.

Signs & symptoms

Focal findings, abrupt onset, fever, headache, or declining consciousness.

Focused exam

Record GCS components, pupils, speech, gaze, motor symmetry, sensation, coordination, and gait when safe; Compare findings with baseline and collateral history.

Brief pathophysiology

Stroke may cause altered loc / confusion through a time-sensitive process capable of rapid physiological deterioration.

Vital-sign pattern

What the trend may show

Possible pattern

Stroke is a clinical diagnosis supported by time course and neurologic findings. Blood pressure and glucose affect eligibility and mimics; normal vitals do not exclude stroke.

Blood pressure (mmHg)

Often elevated

Hypertension is common in acute stroke; hypotension suggests another cause or poor perfusion.

Blood glucose (mmol/L)

Check every patient

Hypoglycemia can mimic focal deficit; hyperglycemia may accompany stress or diabetes.

Heart rate (bpm)

Assess rate / rhythm

An irregular rhythm may suggest atrial fibrillation but is not required.

Oxygen saturation (SpO₂)

Usually preserved

Hypoxemia requires correction and may indicate aspiration or another process.

Front-load in the triage report

  • Stroke: Focal findings, abrupt onset, fever, headache, or declining consciousness.
  • Last known normal.
  • Cognitive baseline.
Intracranial hemorrhageTime-sensitive high-risk possibility

HPI

Clarify cognitive baseline; gcs and trend; bgl.

Signs & symptoms

Focal findings, abrupt onset, fever, headache, or declining consciousness.

Focused exam

Compare findings with baseline and collateral history; Document E/V/M, pupils, focal neurology, attention, skin, respiratory pattern, trauma, and toxidrome findings.

Brief pathophysiology

Intracranial hemorrhage may cause altered loc / confusion through a time-sensitive process capable of rapid physiological deterioration.

Vital-sign pattern

What the trend may show

Possible pattern

Hemorrhage is a trend diagnosis: tachycardia and narrowing pulse pressure may precede hypotension. Age, pregnancy, medications, and pacing can blunt expected responses.

Heart rate (bpm)

Often rises

Tachycardia is a common compensatory response but may be absent.

Pulse pressure (mmHg)

May narrow

Narrowing pulse pressure can reflect reduced stroke volume.

Blood pressure (mmHg)

May fall late

A normal pressure does not exclude significant compensated hemorrhage.

MAP (mmHg)

May fall

A falling trend supports worsening perfusion; interpret with mental status and skin signs.

Front-load in the triage report

  • Intracranial hemorrhage: Focal findings, abrupt onset, fever, headache, or declining consciousness.
  • Cognitive baseline.
  • GCS and trend.
CNS infectionTime-sensitive high-risk possibility

HPI

Clarify gcs and trend; bgl; focal neurology.

Signs & symptoms

Focal findings, abrupt onset, fever, headache, or declining consciousness.

Focused exam

Compare findings with baseline and collateral history; Document E/V/M, pupils, focal neurology, attention, skin, respiratory pattern, trauma, and toxidrome findings.

Brief pathophysiology

CNS infection may cause altered loc / confusion through a time-sensitive process capable of rapid physiological deterioration.

Vital-sign pattern

What the trend may show

Possible pattern

CNS infection may produce fever and systemic illness, but classic findings and abnormal vitals can be absent. Altered mental status, rash, shock, or seizures increase urgency.

Temperature (°C)

Often elevated

Fever supports infection; normal temperature does not exclude it.

Heart rate (bpm)

May rise

Tachycardia may reflect fever, pain, or sepsis.

Blood pressure (mmHg)

May fall with sepsis

Hypotension suggests systemic involvement or shock.

Blood glucose (mmol/L)

Check early

Glucose disturbance is an important reversible mimic of altered mentation or seizure.

Front-load in the triage report

  • CNS infection: Focal findings, abrupt onset, fever, headache, or declining consciousness.
  • GCS and trend.
  • BGL.
Common2 conditions
DeliriumCommon presentation pattern

HPI

Clarify last known normal; cognitive baseline; gcs and trend.

Signs & symptoms

Fluctuation, inattention, infection, dehydration, medication, or organ failure may contribute.

Focused exam

Record GCS components, pupils, speech, gaze, motor symmetry, sensation, coordination, and gait when safe; Compare findings with baseline and collateral history.

Brief pathophysiology

Delirium may explain the presenting symptoms through a common clinical mechanism, while serial assessment checks for complications or an alternate cause.

Vital-sign pattern

What the trend may show

Possible pattern

Neurologic differentials often have nonspecific vital signs. Glucose, pressure, oxygenation, and cardiac rate/rhythm help identify mimics and prevent secondary injury.

Blood glucose (mmol/L)

Check early

Hypoglycemia can mimic or worsen neurologic dysfunction.

Blood pressure (mmHg)

Trend pressure

Both hypo- and hypertension can be clinically important in neurologic disease.

Oxygen saturation (SpO₂)

Prevent hypoxemia

Low saturation can worsen brain injury or suggest an alternate cause.

Heart rate (bpm)

Assess rate / rhythm

Rhythm disturbance can cause cerebral hypoperfusion or embolic events.

Front-load in the triage report

  • Fluctuation, inattention, infection, dehydration, medication, or organ failure may contribute.
  • Last known normal.
  • Cognitive baseline.
Metabolic encephalopathyCommon presentation pattern

HPI

Clarify cognitive baseline; gcs and trend; bgl.

Signs & symptoms

Fluctuation, inattention, infection, dehydration, medication, or organ failure may contribute.

Focused exam

Compare findings with baseline and collateral history; Document E/V/M, pupils, focal neurology, attention, skin, respiratory pattern, trauma, and toxidrome findings.

Brief pathophysiology

Metabolic encephalopathy may explain the presenting symptoms through a common clinical mechanism, while serial assessment checks for complications or an alternate cause.

Vital-sign pattern

What the trend may show

Possible pattern

Neurologic differentials often have nonspecific vital signs. Glucose, pressure, oxygenation, and cardiac rate/rhythm help identify mimics and prevent secondary injury.

Blood glucose (mmol/L)

Check early

Hypoglycemia can mimic or worsen neurologic dysfunction.

Blood pressure (mmHg)

Trend pressure

Both hypo- and hypertension can be clinically important in neurologic disease.

Oxygen saturation (SpO₂)

Prevent hypoxemia

Low saturation can worsen brain injury or suggest an alternate cause.

Heart rate (bpm)

Assess rate / rhythm

Rhythm disturbance can cause cerebral hypoperfusion or embolic events.

Front-load in the triage report

  • Fluctuation, inattention, infection, dehydration, medication, or organ failure may contribute.
  • Cognitive baseline.
  • GCS and trend.
Mimics1 condition
IntoxicationImportant alternative presentation

HPI

Clarify last known normal; cognitive baseline; gcs and trend.

Signs & symptoms

A plausible exposure does not exclude trauma, hypoglycemia, or infection.

Focused exam

Record GCS components, pupils, speech, gaze, motor symmetry, sensation, coordination, and gait when safe; Compare findings with baseline and collateral history.

Brief pathophysiology

Intoxication can resemble altered loc / confusion through overlapping symptoms or referred physiology despite a different primary mechanism.

Vital-sign pattern

What the trend may show

Possible pattern

Neurologic differentials often have nonspecific vital signs. Glucose, pressure, oxygenation, and cardiac rate/rhythm help identify mimics and prevent secondary injury.

Blood glucose (mmol/L)

Check early

Hypoglycemia can mimic or worsen neurologic dysfunction.

Blood pressure (mmHg)

Trend pressure

Both hypo- and hypertension can be clinically important in neurologic disease.

Oxygen saturation (SpO₂)

Prevent hypoxemia

Low saturation can worsen brain injury or suggest an alternate cause.

Heart rate (bpm)

Assess rate / rhythm

Rhythm disturbance can cause cerebral hypoperfusion or embolic events.

Front-load in the triage report

  • A plausible exposure does not exclude trauma, hypoglycemia, or infection.
  • Last known normal.
  • Cognitive baseline.
Red flags

Findings that should escalate concern

  • Falling GCS, focal deficit, meningism, severe headache, shock, hypoventilation, head trauma, or persistent unexplained change is time-sensitive.
  • Stroke, intracranial hemorrhage, or CNS infection: Focal findings, abrupt onset, fever, headache, or declining consciousness.
Related medications

Medication recognition

AmoxicillinLevetiracetamCephalexinDoxycyclineLamotrigineValproic acid
Related EMS presentations

Continue the clinical pathway

NeurologicStroke / TIAToxicologyOverdose / drug poisoningNeurologicSeizureTraumaHead injuryEndocrine/MetabolicHypoglycemiaNeurologicDelirium / acute behavioural change
References

Clinical and academic sources

Curated clinical guidance and peer-reviewed evidence supporting this presentation. Current BCEHS guidance, medical direction, and local policy remain authoritative for practice.

BCEHS Handbook — specific CPGs

  1. F01: Altered Levels of ConsciousnessBC Emergency Health Services Handbook

    Official BCEHS clinical practice guidance for altered levels of consciousness.

Supporting clinical and academic evidence

  1. CEDIS Presenting Complaint List updateCanadian Association of Emergency Physicians

    Presenting-complaint terminology and categorization context. It does not establish a prehospital “top 100” ranking.

  2. WHO Medical Emergency ChecklistWorld Health Organization

    A structured emergency assessment framework intended to reduce missed life-threatening conditions.

  3. Current Trends for Delirium Screening within the Emergency DepartmentMedicina · 2023

    Recognition of delirium, serial cognition assessment, and the need to search for underlying physiological causes.