Altered mental status: Difference between revisions

Revision as of 23:06, 20 March 2026

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

Hypoxic encephalopathy
Acute toxic-metabolic encephalopathy (Delirium)
- Hypoglycemia
- Hyperosmolar state (e.g., hyperglycemia)
- Electrolyte Abnormalities (hypernatremia or hyponatremia, hypercalcemia)
- Organ system failure
- Hepatic Encephalopathy
- Uremia/Renal Failure
- Endocrine (Addison's disease, Cushing syndrome, hypothyroidism, myxedema coma, thyroid storm)
- Hypoxia
- CO2 narcosis
Hypertensive Encephalopathy
Toxins
TTP / Thrombotic thrombocytopenic purpura
Alcohol withdrawal
Drug reactions (NMS, Serotonin Syndrome)
Environmental causes
- Hypothermia
- Hyperthermia
Deficiency state
- Wernicke encephalopathy
- Subacute Combined Degeneration of Spinal Cord (B12 deficiency)
- Vitamin D Deficiency
- Zinc Deficiency
Sepsis
Osmotic demyelination syndrome (central pontine myelinolysis)
Limbic encephalitis

Primary CNS disease or trauma

Direct CNS trauma
- Diffuse axonal injury
- Subdural/epidural hematoma
Vascular disease
- Intraparenchymal hemorrhage
SAH
Stroke
- Hemispheric, brainstem
CNS infections
Neoplasms
- Paraneoplastic Limbic encephalitis
- Malignant Meningitis
- Pancreatic Insulinoma
Seizures
- Nonconvulsive status epilepticus
- Postictal state
Dementia

Psychiatric

Evaluation

AMS Workup

Common Orders

Point of care glucose
CBC
Chemistry
LFTs
UA
CXR
Utox
ECG
Head CT
CAM score

Consider Based on Clinical Situation

Blood and urine cultures
Ammonia level
Tylenol/Aspirin level
LP
Serum Osm
Coags
Cortisol
ABG/VBG
CO level

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

References

Authors:

@@ Line 1: / Line 1: @@
 {{AdultPage|altered mental status (peds)}}
 ==Background==
-*Acute alteration in brain function
+*Altered mental status (AMS) is one of the most common and challenging presentations in the ED
-**May include alteration of arousal or awareness, thought content, memory, or attention
+*Encompasses a spectrum from mild confusion to deep [[coma]]
-*Both cerebral cortices or brainstem must be affected
+*May include alteration of arousal (level of consciousness), awareness, thought content, memory, or attention
-*[[Delirium]] vs [[dementia]] vs other organic pathology vs functional (psychiatric)
+*Both cerebral cortices or the brainstem reticular activating system must be affected
-*Must quickly determine if [[coma]] is from diffuse or focal impairment
+*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==
-*Depends on cause
+*History from family/EMS/bystanders is critical:
-**Diffuse brain dysfunction - lack of focal findings
+**Baseline mental status and functional level
-**[[focal neuro deficits|Focal brain dysfunction]] - hemiparesis, loss of motor tone, loss of ocular reflexes
+**Onset (sudden vs gradual), preceding symptoms, recent medications/substances
-*Important to differentiate diffuse brain dysfunction from localized lesion as a patient may appear confused due to visual deficit, dysphasia, etc.
+**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==
@@ Line 18: / Line 33: @@
 ==Evaluation==
 {{AMS workup}}
+*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==
-*Patients with focal findings may have surgically treatable cause
+*'''ABCs first:'''
-*Coma cocktail
+**Protect airway — intubate if GCS ≤8 or unable to protect airway
-**[[dextrose|Glucose]], [[thiamine]], [[naloxone]]
+**O2, IV access, continuous monitoring
-*Treat underlying cause
+*'''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==
-*Most frequently admission, unless of a chronic and known etiology
+*'''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
 ==See Also==
-*[[Toxicology (Main)]]
-*[[Glasgow Coma Scale (GCS)]]
 *[[Altered mental status (peds)]]
-*[[AVPU Scale]]
+*[[Coma]]
-*[[Brain Death]]
+*[[Delirium]]
+*[[Glasgow Coma Scale]]
+*[[Syncope]]
 ==References==
 <references/>
 [[Category:Neurology]]
 [[Category:Symptoms]]