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Delirium Research

The Impact of Delirium

Ill and hospitalized older people can experience sudden episodes of delirium, a state of confusion and disorientation that can last hours, days, or weeks. People with delirium may not be able to think clearly, pay attention, or be aware of their surroundings.

For centuries considered a transient and reversible condition, delirium in older people is still viewed by many to be a normal consequence of surgery, chronic disease, illness, or infection.

There is mounting evidence, however, that delirium may be associated with increased risk for dementia and may contribute to morbidity and death. One recent study found that in a group of 553 people age 85 and older, those with a history of delirium had an eight-fold increase in risk for developing dementia. The researchers also found that among the participants with dementia, delirium was associated with an acceleration of dementia severity, loss of independent functioning, and higher mortality. These findings showed that delirium is a strong risk factor for dementia and cognitive decline in the oldest old.


Delirium often involves a quick change between mental states (for example, from lethargy to agitation and back to lethargy) Symptoms may include:

  • Fluctuating alertness (usually more alert in the morning, less at night)
  • Hallucinations and delusions
  • Variable levels of consciousness or awareness
  • Disrupted sleep patterns, drowsiness
  • Confusion (disorientation) about time or place
  • Declines in short-term memory and recall
  • Disorganized thinking, talking in a way that doesn't make sense
  • Emotional changes: anger, agitation, depression, irritability, overexcitement
  • Incontinence
  • Problem concentrating

Contributing Factors

A number of medical and physical conditions may play a role in the onset of delirium, especially in older people:

  • Use of pain medication or sedatives, or sedative drug withdrawal
  • Drug or alcohol abuse
  • Dehydration
  • Electrolyte or other body chemical disturbances
  • Infections such as urinary tract infections or pneumonia
  • Poisons
  • Recent surgery
  • Disrupted and/or insufficient sleep


Treatment depends on the condition of the patient, the level of pain, the medical history, and a variety of other considerations. The goal of treatment is to manage the symptoms. The person may need to stay in the hospital for a short time. Some examples of ways to manage symptoms include:

  • Allowing older people to sleep undisturbed between 10 p.m. and 6 a.m. so that their normal sleep cycle is less disrupted.
  • Stopping or changing medications that may contribute to delirium to try to improve mental function. After asking about your medical history to establish a "baseline," for example, your doctor may discuss medicines and substances that can worsen confusion, such as alcohol.
  • Using low doses of medicines that control aggression or agitation, and adjusting the dose. These are usually started as needed.
  • Behavior modification to control unacceptable or dangerous behaviors.
  • Reality orientation to reduce disorientation. Reality orientation can include calendars, clocks, and anything that stimulates the senses to the present surroundings.
  • Ensuring the patient has a hearing aid, glasses, or other devices necessary to aid communication.

Disorders that contribute to delirium should be treated. These may include:

  • Anemia
  • Decreased oxygen (hypoxia)
  • Heart failure
  • High carbon dioxide levels (hypercapnia)
  • Infections
  • Kidney failure
  • Liver failure
  • Nutritional disorders
  • Psychiatric conditions (such as depression)
  • Thyroid disorders

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Outlook (Prognosis)

Cognitive dysfunction due to delirium in the setting of dementia may be reversible by treating the underlying acute illness. Full recovery is common, but depends on the underlying cause of the delirium. It may take several weeks for cognitive function to return to normal. However, more and more clinical data suggests that delirium may persist for weeks and even months.

Possible Complications

  • Loss of ability to function or care for self
  • Loss of ability to interact
  • Increased likelihood of hospital acquired infections, longer hospital stays, and nursing home placements
  • Side effects of medications used to treat the disorder

When to Contact a Medical Professional

Call your health care provider if there is a rapid change in mental status.


Treating the conditions that may produce delirium can reduce its risk. In hospitalized patients, avoiding sedatives, prompt treatment of metabolic disorders and infections, and using reality orientation programs may reduce the risk of delirium in those at high risk.

Read More "Delirium Research" Articles

Where Am I? / Digging Into the Mysteries of Delirium / The Impact of Delirium

Fall 2015 Issue: Volume 10 Number 3 Page 16-17