An organic confusional state
Much faster course than dementia (which is gradual, over months to years)
Defined as
A global inability to relate to the environment and process sensory input
NOT defined as
Alterations in mental status resulting from extreme emotional stimulus (this is a functional abnormality instead)
Sx
Acute onset of a disturbance in the level of consciousness, cognition and attentiveness (c.f. demential where consciousness is preserved)
Increased alertness and psychomotor activity
May have hallucinations
Disturbances in consciousness, cognition and perception; which tend to occur over a short period of time (hours to days)
May be agitated and combative or calm and quiet
Thought process may be mildly disturbed or glossly disorganized
May be subdued or explosive and can fluctuate over minutes to hours
Sleep-wake cycle may be altered or reversed
Agitation is often present during the night
Elderly patients with delirium may have low, normal or high temperature
NOT Sx
Oriented (patients are more likely to have functional causes for altered mental status)
Ddx
Medications (22-39% of cases in the elderly)
Infection
Metabolic abnormality
Hepatic encephalopathy
Acute renal failure
Diabetic ketoacidosis
Hyperosmolarity
Tx
Treat underlying cause
Minimize stimulation because patients with delirium have difficulty processing stimuli
