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
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