Altered Level of Consciousness¶
Category: Medical Sources: raw/protocols/nm-sop-guidelines-treatment-2022.pdf; UCLA EMT Ultimate Study Guide (2026) Last updated: 2026-05-06
Overview¶
Altered level of consciousness (ALOC) is a common EMS presentation with a wide differential diagnosis spanning metabolic, neurologic, toxicologic, traumatic, cardiovascular, and environmental causes. It is not a diagnosis — it is a finding requiring systematic investigation to identify and treat reversible causes. Most causes can be found through methodical assessment: check the glucose, airway, oxygen, and vital signs before anything else.
Key Points¶
- Always check blood glucose in any patient with ALOC — hypoglycemia is common, treatable, and rapidly reversible
- Do not assume intoxication — many medical conditions mimic intoxication
- AVPU scale: Alert, Verbal, Pain, Unresponsive — use to quantify and trend LOC
- GCS (Glasgow Coma Scale) — used in trauma with TBI; Eyes (1–4) + Verbal (1–5) + Motor (1–6); score ≤8 = severe TBI, typically requires airway management
- Unresponsive patients cannot protect their airway — position laterally, be prepared to suction
- The underlying cause drives definitive treatment — EMT-B focuses on life-threatening causes and transport
Common Causes (AEIOU TIPS mnemonic or similar)¶
- A — Alcohol/Acidosis
- E — Epilepsy/seizure
- I — Insulin/hypoglycemia
- O — Overdose/opioids
- U — Uremia (renal failure)
- T — Trauma/head injury
- I — Infection (CNS, sepsis)
- P — Psychiatric/psychogenic
- S — Stroke/syncope
NM protocol list: - Diabetic emergency, overdose, CVA/TIA, AMI, head trauma, dehydration, syncope, hypo/hyperthermia, shock or hypoperfusion, CNS infection
Assessment Relevance¶
Primary assessment (primary-assessment): - Airway: impaired LOC = impaired airway reflexes; suction, position, OPA/NPA - Breathing: rate, depth, quality; SpO2 - Circulation: HR, BP, skin (color, temperature, moisture) - AVPU scale — repeat at each reassessment to trend
History (history-taking): - SAMPLE: Prior medical conditions, medications (especially insulin, anticoagulants, seizure meds, cardiac meds), allergies, last meal, events preceding onset - Bystander/family input essential — patient may be unable to provide history - Onset: sudden (stroke, cardiac, hypoglycemia) vs. gradual (infection, DKA, hypothermia)
Physical exam (secondary-assessment): - Glucometry — mandatory first action after ABCs - Pupils: equal and reactive vs. unequal (herniation, drugs), pinpoint (opioids), blown (herniation) - Breath odor: acetone (DKA), alcohol, urine (renal failure) - Skin: pale/cool/moist (hypoglycemia, shock), hot/dry (hyperthermia, anticholinergic), jaundice (liver) - Focal neurologic deficits: stroke, TBI - Evidence of trauma (head wound, Battle's sign, raccoon eyes)
Procedures¶
- Scene size-up (scene-size-up): safety, MOI vs. NOI, need for additional resources; if trauma possible, c-spine consideration
- Primary assessment (primary-assessment): airway management is first priority — suction, position, OPA/NPA if no gag reflex
- Glucometry: if <60 mg/dL with AMS → treat per diabetic-emergencies
- If narcotic overdose suspected → naloxone per overdose-poisoning guideline
- Manage hypoxia with supplemental O2 per oxygen-administration
- If shock suspected → treat per bleeding-control-shock
- Transport without delay to appropriate facility
- Request ALS intercept (IV dextrose for unconscious hypoglycemia is ALS scope)
- Reassess every 5 minutes (reassessment): trend LOC, vital signs, treat identified causes
NM Protocol Notes¶
From NM EMS Treatment Guidelines (2022):
EMT-B scope: - Primary assessment: airway, breathing, circulation — if occult trauma possible, consider spinal immobilization - Cardiac monitoring and 12-lead EKG if possible - Consider possible causes: diabetic emergency, overdose, CVA/TIA, AMI, head trauma, dehydration, syncope, hypo/hyperthermia, shock/hypoperfusion, CNS infection - Perform glucometry: - If BGL <60 mg/dL and/or associated signs of hypoglycemia → follow Diabetic Emergencies Guideline - If narcotic overdose suspected → follow Overdose/Poisoning Guidelines - Transport without delay to appropriate medical facility - If no ILS/ALS capability → radio for intercept - If signs of shock → follow Shock Guidelines - Active cooling or warming if indicated (hyperthermia, hypothermia) - If cardiac cause suspected → follow specific Cardiac Emergency Guidelines
ALS scope (IV access, IV dextrose, naloxone IV) — EMT-B should initiate ALS intercept early for unconscious patients
Post-ROSC: Check BGL after cardiac arrest — if <60 mg/dL treat per diabetic emergencies; if hyperglycemic, notify hospital
Note on naloxone: After naloxone, patient may rapidly awaken, become combative, and experience vomiting — consider this before inserting advanced airway device
NREMT Relevance¶
- AVPU and GCS scale — know components and scoring
- Always check BGL in ALOC
- Medical causes mimic intoxication — never assume alcohol
- Airway management priority: lateral position, suction, OPA/NPA for unconscious with no gag reflex
- AEIOU TIPS mnemonic for ALOC causes
- GCS ≤8 = severe TBI = needs airway management
NREMT Differentiators¶
AEIOU-TIPS — Expanded¶
| Letter | Cause | Key Clue |
|---|---|---|
| A | Alcohol / Acidosis | Odor; slow speech; DKA (acetone breath) |
| E | Epilepsy / Seizure | Postictal confusion; witness reports jerking; incontinence |
| I | Insulin / Hypoglycemia | BGL <60; cool, clammy, diaphoretic; rapid onset |
| O | Overdose / Opioids | Pinpoint pupils; bradypnea; pill bottles |
| U | Uremia (Renal failure) | Urine odor on breath; chronic kidney disease history |
| T | Trauma / Head injury | Mechanism; Battle's sign; raccoon eyes; Cushing's Triad |
| I | Infection (CNS / Sepsis) | Fever; stiff neck; headache; warm flushed skin |
| P | Psychiatric / Psychogenic | Rule out all medical causes first |
| S | Stroke / Syncope | Focal deficits; FAST positive; unequal pupils |
NREMT RULE: BGL is ALWAYS the first step after ABCs in any ALOC patient. Hypoglycemia is the most common, most reversible cause — and it looks like everything else (stroke, intoxication, seizure, psychiatric).
AVPU vs. GCS¶
AVPU (prehospital field tool):
| Level | Meaning |
|---|---|
| A — Alert | Awake, aware, appropriate |
| V — Verbal | Responds to voice (not necessarily appropriately) |
| P — Pain | Responds only to painful stimuli |
| U — Unresponsive | No response to any stimuli |
GCS (Glasgow Coma Scale — trauma/TBI focus):
| Component | Score Range | Best Score |
|---|---|---|
| Eyes (E) | 1–4 | 4 = opens spontaneously |
| Verbal (V) | 1–5 | 5 = oriented |
| Motor (M) | 1–6 | 6 = obeys commands |
| Total | 3–15 | 15 = normal |
KEY DIFFERENTIATOR — GCS ≤8: GCS ≤8 = severe TBI = the patient cannot protect their own airway. Advanced airway management is indicated. This is the classic NREMT threshold.
NREMT TIP: AVPU maps roughly to GCS: Alert=15, Verbal=13, Pain=8, Unresponsive=3. Use AVPU in the field; GCS for trend and documentation.
Pupil Assessment in ALOC¶
| Pupil Finding | Meaning |
|---|---|
| Equal, round, reactive to light (PERRL) | Normal |
| Pinpoint bilateral | Opioid overdose; pontine hemorrhage |
| Dilated bilateral | Stimulant overdose (cocaine, meth); anticholinergic; cardiac arrest hypoxia |
| Unequal (anisocoria) | Herniation (blown pupil = uncal herniation); structural brain injury; old injury |
| Fixed, dilated bilateral | Herniation (late); cardiac arrest; anticholinergic |
| One pupil blown (blown = large, non-reactive) | Uncal herniation — the worst finding; impending brain death |
KEY DIFFERENTIATOR — Blown Pupil: One fixed, dilated pupil in a ALOC patient = herniation in progress. Cushing's Triad (bradycardia + hypertension + irregular breathing) will often accompany it. Priority transport — do NOT hyperventilate unless herniation confirmed.
Breath Odors as Diagnostic Clues¶
| Odor | Cause |
|---|---|
| Fruity / acetone | Diabetic Ketoacidosis (DKA) |
| Alcohol | Ethanol ingestion |
| Urine / ammonia | Uremia (renal failure) |
| Feces | Bowel obstruction or aspiration |
| Almonds (bitter) | Cyanide poisoning |
| Garlic | Organophosphate poisoning |
Priority Treatment Sequence for ALOC¶
1. Scene safety — trauma mechanism? Spinal precautions?
2. Primary assessment — airway first (lateral position, suction)
3. Check BGL — if <60 mg/dL → treat hypoglycemia
4. O2 — SpO2, manage hypoxia
5. Pupils, skin, odor — find reversible cause
6. Naloxone — if opioid overdose suspected
7. ALS intercept — if cause requires IV dextrose, advanced airway, or medications
8. Transport
Related¶
- diabetic-emergencies — hypoglycemia as primary cause of ALOC
- overdose-poisoning — naloxone for opioid ALOC
- stroke — focal neuro deficits with ALOC
- seizure — post-ictal ALOC
- primary-assessment — AVPU, airway management
- secondary-assessment — glucometry, pupils, focal deficits
- behavioral-psychiatric — psychiatric cause after medical causes ruled out
- geriatric — AMS in elderly is always an emergency; UTI is the #1 cause of acute delirium
Sources¶
raw/protocols/nm-sop-guidelines-treatment-2022.pdf— Altered Level of Consciousness protocol (p. 35)