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Coma & Depressed LOC

Protect, correct the two reversible killers, image.

LearnQuick referenceClinical practice

Your objective: explain the approach, recognize important warning signs, then test your recall.

Abbreviations explained
ACS
Acute coronary syndrome
OMI
Occlusion myocardial infarction
ECG
Electrocardiogram
PE
Pulmonary embolism
POCUS
Point-of-care ultrasound
QTc
QT interval corrected for heart rate
LBBB
Left bundle branch block
RBBB
Right bundle branch block
hs-cTn
High-sensitivity cardiac troponin
CTA
Computed tomography angiography
ICU
Intensive care unit
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The jobProtect, correct the two reversible killers, image.

  1. Airway, glucose, oxygen — naloxone and thiamine as indicated (never delay dextrose).
  2. Pupils, breathing pattern, and brainstem reflexes localise structure vs toxin.
  3. Non-contrast CT for structural causes; EEG if non-convulsive status is possible.
  4. Do not label it “alcohol” without glucose, a CT, and a level.

Coma is failure of both hemispheres or the ascending reticular activating system.

Airway, glucose, oxygen, and naloxone/thiamine are given empirically while the exam localizes the lesion (breathing pattern, pupils, brainstem reflexes, motor tone) and imaging defines structure.

Hypoglycemia Critical

Key: Glucose every time — the most treatable cause of coma.

Opioid overdose Critical

Key: Pinpoint pupils + hypoventilation — titrate naloxone to breathing.

Herniation (uncal / central) Critical

Key: Blown or unilateral pupil, posturing, Cushing reflex — hypertonic saline/mannitol, neurosurgery.

Massive ICH / SAH / basilar occlusion Critical

Key: Non-contrast CT immediately; basilar thrombosis can present as coma without lateralizing signs.

Non-convulsive status epilepticus Critical

Key: Coma with subtle myoclonus — EEG; treat without waiting.

Meningoencephalitis Critical

Key: Fever or no focus — empiric therapy when suspected.

Wernicke encephalopathy Critical

Key: Alcohol use/malnutrition — give thiamine with (or immediately after) glucose; never delay dextrose.

Toxic-metabolic (CO, TCA, hypothermia) Critical

Key: ECG, temperature, anion/osmolar gaps; deep coma with intact pupillary reflexes suggests toxin.

Tick what your patient has — the banner updates as you go.

EMS/family

speed of onset, preceding symptoms (headache, seizure, fever, chest pain)

Access to medications/toxins; alcohol; psychiatric history

Trauma — especially falls in the anticoagulated

End-organ disease

liver, renal, diabetes, thyroid

ABCDE; GCS with attention to airway reflexes

Pupils

metabolic causes = small and reactive; structural = asymmetric/fixed

Breathing pattern

Cheyne-Stokes, central hyperventilation, apneustic

Brainstem reflexes

oculocephalic/cold caloric, corneal, cough

Motor

tone, symmetry, posturing to noxious stimulus

Trauma stigmata; skin for cyanosis, tracks, rash

Bedside

  • Glucose immediately; naloxone/thiamine as indicated
  • ECG; VBG/ABG; core temperature

Labs

  • Electrolytes (Na, Ca), renal/hepatic panels, ammonia, lactate, CBC, coagulation
  • Targeted toxicology; TSH; cortisol if endocrine suspicion

Imaging / monitoring

  • Non-contrast head CT first among structural tests
  • EEG for non-convulsive status; LP after imaging when indicated
Medication safety reminder

Use this as a first-pass prompt; verify all medications, doses, concentrations, contraindications, weight, pregnancy status, and local protocols before administration.

Check indication, allergy, route, renal/hepatic risk, interactions, monitoring, and local formulary.

Discharge

  • Rare — only full recovery from a clearly reversible cause with observation and follow-up (e.g., brief hypoglycemia in a reliable setting).

Admit (monitored)

  • Post-ictal or toxic with improving exam and a secured airway plan; correcting metabolic derangements.

ICU / neurosurgery

  • Undifferentiated coma, herniation signs, ICH/SAH, status epilepticus, need for airway protection.

Use objective reassessment and the local pathway.

Before the next decision · reassess and hand over

Use these learning prompts with the presentation’s pathway. They are not discharge criteria.

  1. Reassess: compare symptoms, observations and examination with the initial assessment and response to treatment.
  2. Warning signs for Coma & Depressed LOC:
    • Unequal or fixed-dilated pupils
    • Motor posturing or irregular breathing
    • Falling GCS, seizures, or hyperthermia
    • Hypoglycemia unresponsive to therapy; hypothermia
    • Meningeal signs with rapid progression
    • Anticoagulation with any trauma history
  3. Reconsider: check unresolved findings and alternative explanations, including the pitfalls below.
  4. Escalate: communicate deterioration, uncertainty or needs beyond the current setting.
  5. Plan the transition: identify outstanding results, responsibility for follow-up, patient understanding and specific return advice.
Review this presentation’s disposition pathway →Practice a handover →

Clinical Pearls

  • Glucose, oxygen, and naloxone are given empirically while the exam localizes.
  • Basilar artery occlusion can present as coma without lateralizing signs — think CTA/CTP or MRI if CT is unrevealing.
  • The FOUR score captures brainstem findings that GCS misses.
  • Intact pupillary reflexes in deep coma point toward toxin/metabolic more than structure.

Pitfalls

  • Locked-in syndrome mimics coma — check for vertical eye movements.
  • Small reactive pupils + deep coma = toxin more often than structure.
  • Never attribute coma to “alcohol” without glucose, a CT, and a level.
  • Hypothermia halts almost everything — rewarm before declaring brainstem reflexes lost.
  • Non-convulsive status hides inside “post-ictal” labels.
  • Never delay dextrose for thiamine — give them together.
PRACTICE REFRESHER

Rapid recall

Test your first action and the dangerous diagnoses before revealing the answer.

01 · First move

Before you scroll, what needs to happen first?

02 · Immediate threats

Name at least two diagnoses that cannot wait.

PRIVATE TO THIS DEVICE

Your learning note

Capture a weak point, a teaching pearl, or a question to take to your next shift.

Review schedule starts when marked reviewed
Altered Mental StatusSeizuresPoisoning & OverdoseShockECG Guide

Selected guidance · source check 2026-09-07. These 2 source links support selected teaching points, not a complete review of this topic. Check population, setting and local protocol before applying a recommendation.

  • Rosen’s Emergency Medicine, 10th ed. (2023) — coma & depressed level of consciousness
  • FOUR score (Wijdicks et al., Ann Neurol 2005)
  • Neurocritical Care Society guidance
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