Author: Susan Gorman, MSN, RN, GNP & Kathleen Pace Murphy, PhD, MS

Key Points



Delirium may be classified as:

Delirium is often a symptom of a serious illness in older adults; and sometimes the only presenting symptom.

Delirium is associated with prolonged hospitalization, functional decline, and increased use of chemical and physical restraints.

Factors that precipitate delirium can be remembered using the mnemonic DELIRIUM
Drug use (hypnotics, anticholinergic)
Electrolyte abnormalities
Lack of drugs (withdrawal)
Reduced sensory input (blindness, deafness
Intracranial problems (stroke)
Urinary retention and fecal impaction
Myocardial problems (MI, heart failure, arrhythmias).



Delirium assessment includes utilizing the Confusion Assessment Method (CAM) developed by Sharon K. Inouye (2006).

The CAM has 4 Features:

  1. Acute Onset and Fluctuating Course: Is there evidence of an acute change in mental status from patient's baseline? This is usually best answered by someone close to the patient, such as family, a care provider, or a nurse.
  2. Inattention: Did the patient have difficulty focusing? Were they easily distracted or could they not stay awake?
  3. Disorganized Thinking: Was the patient's thinking disorganized or incoherent?
  4. Altered Level of Consciousness: Overall, how would you rate this patient's level of consciousness? The answer should be anything other than alert (normal).
For the CAM to be positive for delirium, it requires the presence of both features 1 and 2, AND either 3 or 4. 

The following table is helpful in distinguishing dementia from delirium:

Dementia and Delirium Comparative Table
Dementia Delirium
Onset Insidious Rapid associated with an identified event
Main symptom Loss of memory, especially recent event(s) Inattention
Etiology May be related to underlying brain disorder, such as Alzheimer disease, vascular dementia, or Lewy body dementia Nearly always related to underlying acute change, such as dehydration, infection, or starting or stopping medications
Orientation Impaired Fluctuates
Level of consciousness May be normal until advanced stages Fluctuates
Language May be problematic with word choices Slowed or rapid speech, frequently with incoherent and/or inappropriate language
Progression Slow Causes variations in mental function- people are alert one moment and sluggish and drowsy the next
Development Often permanent Fluctuates; days to weeks to months
Treatment Needed; slows progression but does not cure Immediate; usually reversible

Table Source: Ehlenbach, Hough, Crane, Haneuse, Carson, Randall, & Larson, (2010); Fong, Tubevaev, & Inouye, (2009); Inouye (2006a) (2006b).



Identify and treat the underlying cause of delirium (i.e. infection, drugs, electrolyte imbalance).

Reassure the patient by having well known family members or caregivers at the bedside.

Discern day from night surroundings (decreased stimulation at night to promote sleep; blinds open during day with more activity).

Avoid bed rest if possible and the use of restraints (chemical or physical).

Encourage interprofessional interventions:


Additional Web-based educational resources:

Delirium: Acute Confusional State. Pub Med Health (2013): 

YouTube: How to recognize delirium



Ehlenbach, W.J., Hough, C.L., Crane, P.K., Haneuse, S.J.P.A., Carson, S.S., Randall Curtis, J., & Larson, E.B. (2010). Association between acute care and critical illness hospitalization and cognitive function in older adults. Journal of American Medical Association, 303(8), 763-770.

Fong, T.G., Tubevaev, S.R., & Inouye, S.K. (2009). Delirium in elderly adults: Diagnosis, prevention and treatment. National Review of Neurology, 5(4):210-220. Doi:10.1038/nrneurology.209.24. Retrieve from

Inouye, S. (2006a). Delirium in older persons. New England Journal of Medicine, 354(11), 57-65.

Inouye, S. (2006b). Geriatrics At Your Fingertips (9th Ed.) New York: The American Geriatrics Society.