Altered mental status

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This page is for adult patients. For pediatric patients, see: altered mental status (peds)

Background

  • Altered mental status (AMS) is one of the most common and challenging presentations in the ED
  • Encompasses a spectrum from mild confusion to deep coma
  • May include alteration of arousal (level of consciousness), awareness, thought content, memory, or attention
  • Both cerebral cortices or the brainstem reticular activating system must be affected
  • Key distinctions:
    • Delirium: Acute, fluctuating alteration in attention and awareness; typically reversible
    • Dementia: Chronic, progressive cognitive decline; not typically an ED diagnosis
    • Psychiatric: Diagnosis of exclusion — always rule out organic causes first
  • Must quickly determine if the altered state is from diffuse (metabolic/toxic) or focal (structural/vascular) impairment

Clinical Features

  • History from family/EMS/bystanders is critical:
    • Baseline mental status and functional level
    • Onset (sudden vs gradual), preceding symptoms, recent medications/substances
    • Medical history: diabetes, liver/kidney disease, seizures, psychiatric history, substance use
  • Physical exam priorities:
    • Vital signs: Fever (infection, toxidrome), hypothermia, hypo/hypertension, tachycardia, hypoxia
    • Glucose: Point-of-care immediately
    • Neurologic exam:
      • Level of consciousness (Glasgow Coma Scale)
      • Pupil size and reactivity
      • Focal deficits (hemiparesis, facial droop, gaze preference) → suggests structural lesion
      • Diffuse findings (no lateralizing signs) → suggests metabolic/toxic cause
    • Skin: Needle tracks, jaundice, rash (meningococcemia, petechiae), diaphoresis, dryness
    • Odor: Alcohol, fruity (DKA), fetor hepaticus
    • Meningeal signs: Nuchal rigidity (meningitis, SAH)

Differential Diagnosis

Altered mental status

Diffuse brain dysfunction

Primary CNS disease or trauma

Psychiatric

Evaluation

AMS Workup

Common Orders


Consider Based on Clinical Situation

  • Additional workup based on clinical suspicion:
    • CT head without contrast — if trauma, focal deficits, no clear metabolic cause, or concern for hemorrhage
    • Lumbar puncture — if meningitis/encephalitis suspected (after CT if indicated)
    • EEG — if nonconvulsive status epilepticus suspected (prolonged postictal state, subtle motor activity)
    • CT angiography — if acute stroke suspected
    • Toxicology screen — urine drug screen; consider serum levels (ethanol, salicylate, acetaminophen, lithium)
    • Blood gas (VBG/ABG) — for acid-base disturbances, CO levels
    • Ammonia — if hepatic encephalopathy suspected
    • Thyroid function — if no other cause identified (myxedema coma, thyroid storm)
    • Cortisol — if adrenal crisis suspected

Management

  • ABCs first:
    • Protect airway — intubate if GCS ≤8 or unable to protect airway
    • O2, IV access, continuous monitoring
  • Immediate interventions:
    • Dextrose (D50 50 mL IV or D10 titrated) if hypoglycemic
    • Thiamine 100 mg IV (give before or with glucose)
    • Naloxone 0.4-2 mg IV if opioid toxicity suspected
  • Patients with focal findings may have a surgically treatable cause → emergent imaging
  • Treat the underlying cause once identified
  • Avoid sedation/restraints if possible until organic cause excluded; use the least restrictive means necessary for safety

Disposition

  • Admit to ICU:
    • GCS ≤12, declining mental status
    • Intubated patients
    • Hemodynamic instability
    • Suspected CNS infection or stroke requiring acute intervention
  • Admit to floor:
    • AMS with identified cause requiring ongoing treatment/monitoring (e.g., metabolic correction)
    • Elderly with new-onset delirium requiring workup
  • Discharge:
    • Fully resolved AMS with clearly identified and treated benign cause (e.g., hypoglycemia corrected, alcohol intoxication sobered)
    • Reliable follow-up arranged
    • Safe discharge environment

Calculators

Glasgow Coma Scale (GCS)

Glasgow Coma Scale Calculator
Component Response Points
Eye Opening (E) Spontaneous +4
To verbal command +3
To pain +2
No eye opening +1
Verbal Response (V) Oriented +5
Confused +4
Inappropriate words +3
Incomprehensible sounds +2
No verbal response +1
Motor Response (M) Obeys commands +6
Localizes pain +5
Withdrawal from pain +4
Flexion to pain (decorticate) +3
Extension to pain (decerebrate) +2
No motor response +1
GCS Score / 15
Interpretation
13–15 Mild brain injury
9–12 Moderate brain injury
3–8 Severe brain injury — consider intubation if unable to protect airway
References
  • Teasdale G, Jennett B. Assessment of coma and impaired consciousness. Lancet. 1974;2:81-84. PMID 4136544.
  • Teasdale G et al. The Glasgow Coma Scale at 40 years. Lancet Neurol. 2014;13:844-854. PMID 25030516.

See Also

References

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