Altered mental status resident survival guide
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Moises Romo, M.D.
Overview
Altered mental status can result from a variety of factors, including alterations in the chemical environment of the brain, insufficient oxygen or blood flow in the brain, and excessive pressure within the skull. The level of consciousness may decline abruptly or slowly, or it may increase and decrease intermittently. Life threatening causes of altered mental status include malignant hypertension, myocardial infarction, rabies and sepsis. Other common causes of altered mental status include alcohol withdrawal, dehydration, electrolyte disturbance and hypoglycemia.
Causes
Life Threatening Causes
Life-threatening causes include conditions that may result in death or permanent disability within 24 hours if left untreated
- Carbon monoxide toxicity
- Heat stroke
- Hypothermia
- Malignant hypertension
- Myocardial infarction
- Rabies
- Sepsis
Common Causes
- Alcohol withdrawal
- Drug withdrawal
- Dehydration
- Electrolyte disturbance
- Encephalitis
- Epileptic seizures
- Hyperglycemia
- Hypoglycemia
- Meningitis
- Sepsis
Diagnosis
Shown below is an algorithm summarizing the diagnosis of altered mental status according to the the American Academy of Neurology guidelines.
| Patient with amnesia (Amnesia, confusion, loss of alertness, disorientation, disruption of judgement, behavior and perception) | |||||||||||||||||||
| Evaluate ABCDEF • Airway • Breathing • Circulation • Disability (Glasgow coma scale) • Exposure (Rapid head to toe revision) • Fingerstick blood glucose | |||||||||||||||||||
Do's
- Perform an ABCDEF evaluation as a first step.
- If combative, use physical or chemical restraining.
- Take a non-contrasted CT scan of the head before contrasted when head trauma is suspected.
- Sodium imbalances should be slowly corrected to avoid a central pontine myelinolysis or a brain herniation.
Don'ts
- Do not administer glucose before thiamine, when Wernicke encephalopathy is suspected.
- Do not asume psychiatric causes until other triggers are ruled out.