Altered Level Of Consciousness

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Altered mental status is a collective, non-specific term referring to change in cognitive function, behavior, or attentiveness. It includes delirium, dementia, lethargy (state of decreased awareness and alertness i.e. patient may appear wakeful), stupor (unresponsive but rousable), and coma (sleep-like state, not rousable to consciousness).

Possible causes of coma (AEIOU TIPS)

Acidosis/alcohol

Epilepsy

Infection

Oxygen (hypoxia)/opiates

Uremia

Temperature/trauma (esp. to head)

Insulin (too little or too much)

Psychogenic/poisoning

Stroke

Remember “GCS < 8 intubate!” Ability to protect airway is first priority.

History

·      Obtain collateral from family, friends, police, paramedics, old charts, or Medic Alert bracelets etc.

·      Onset and progression

o   Antecedent trauma, seizure activity, fever

o   Abrupt onset suggests CNS hemorrhage/ischemia or cardiac cause

o   Progression over hours to days suggests progressive CNS lesion or toxic/metabolic cause

·      Determine patient’s baseline level of consciousness

·      Past medical history, paying attention to similar episodes, overdose, or concurrent psychiatric disorders (e.g. depression).

Physical examination

·      Vital signs including temperature

·      Cardiac, respiratory, and abdominal exams

·      Complete neurological exam

o   Pupil size and reactivity

o   GCS

Investigations

·      Blood work—rapid blood sugar, CBC, electrolytes, creatinine, BUN, liver function test, glucose, serum osmolality, venous blood gas, coagulation studies, troponins

·      Imaging—CXR, CT head

·      Other tests—ECG, urine analysis, urine toxicology

Diagnosis

·      Administer appropriate universal antidotes

o   Thiamine 100mg IV if history of alcoholism or patient looks malnourished

o   One ampule D50W IV if low blood sugar

o   Naloxone 0.4~2mg IV or IM if opiate overdose is suspected

·      Distinguish between structural and toxic-metabolic coma

o   Structural coma

§  Pupils, extra-ocular movements, and motor findings are usually asymmetrical

§  Look for focal or lateralizing abnormalities

o   Toxic-metabolic coma

§  Dysfunction at lower levels of the brainstem (e.g. caloric unresponsiveness)

§  Respiratory depression in association with an intact upper brainstem (e.g. equal reactive pupils)

§  Extra-ocular movements and motor findings are symmetrical or absent

·      Essential to re-examine frequently because status can change rapidly

·      Diagnosis may become apparent only with the passage of time. Delayed deficit after head trauma suggestive of epidural hematoma (characteristic “lucid interval”).

Disposition

·      Admission if ongoing decreased level of consciousness

·      Discharge if altered level of consciousness is readily reversible; ensure adequate follow-up care