What is delirium?

Delirium (new mental confusion) is a sudden change in mental status, or sudden confusion, which develops over hours to days. It is different from dementia, such as Alzheimer's disease, which is a chronic state of confusion that develops and progresses over time.

There are two types of delirium: hyperactive delirium and hypoactive delirium. Hyperactive means overactive (agitation, restlessness) while hypoactive means underactive (sleepy and hard to respond). Sometimes both types can occur together.

What are the symptoms of delirium?

Hyperactive delirium:

  • Anxiety
  • Restlessness
  • Rapid changes in emotion
  • Hallucinations

Hypoactive delirium:

  • Flat affect
  • Withdrawal
  • Apathy
  • Laziness
  • Decreased responsiveness

What causes delirium?

Some things that may cause delirium are:

  • Drugs
  • Changes in environment
  • Lack of sleep
  • Hormonal issues such as hyper-/hypo-thyroidism
  • Lack of oxygen to tissue
  • Infections such as pneumonia or sepsis
  • Urinary retention (blockage of urine passage)
  • Alcohol or illegal drug overdose
  • Malnutrition
  • Lack of thiamine/vitamin B12
  • Dehydration

What is the risk of developing delirium?

Delirium shows up more often in patients who are at the hospital. Delirium affects 10 to 30% of patients in the hospital who have an illness. Also, more than 50% of people in high-risk populations are affected by delirium. These include people who have had surgery, as well as:

  • 25% of cancer patients
  • 30 to 40% of Human Immunodeficiency Virus (HIV) patients
  • 60% of nursing home residents older than 75 years of age
  • 70% of intensive care patients
  • 80% of patients at the end of life (dying patients)

Patients are at a higher risk for developing delirium if they:

  • Have more than one illness
  • Take more than one type of medicine
  • Have had an illness for a long time
  • Have trouble hearing or seeing
  • Have lack of sleep
  • Have had a stroke
  • Have Parkinson’s Disease, dementia, or chronic liver disease
  • Abruptly stopped using alcohol or drugs (withdrawal)
  • Have burns
  • Are on dialysis
  • Are unable to move because of catheters, restraints
  • Are dehydrated

How will a doctor diagnose delirium?

The doctor will diagnose a patient with delirium if he or she is:

  • Are unable to focus or shift attention
  • Has changes in thinking
  • Has rapid onset of problems in thinking (changes throughout the day)

The doctor will test a patient for any problems in:

  • Speech
  • Attention
  • Memory
  • Orientation
  • Language
  • Visual ability

What are the treatments for delirium?

Delirium is usually caused by other medical conditions. That is why it is important to treat those conditions in order to treat delirium. The doctor should carefully review the patient’s:

  • Medical history
  • Physical exam results
  • Lab results
  • Drug use, including over-the-counter drugs, illicit drugs, and alcohol

Some ways to treat delirium include focusing on the environment. The person with delirium will do best in a quiet setting. Help promote sleep and rest by reducing noise and distraction. The following are tips for caregivers/support people:

  • Reassure the patient and help him or her understand the environment.
  • Explain to the patient what is happening.
  • Bring familiar objects from home (for example, photos, a blanket, a bedside clock) to help make the patient more comfortable in an unfamiliar environment. Soothing music may be beneficial as well.
  • Make sure to talk about current events and family news as this provides mental stimulation. Reading out loud to the patient can be helpful.
  • Make sure that the patient has nutritional food and stays hydrated.

The patient should do as much as possible on his or her own. These actions (which may require assistance) include:

  • Using an interpreter to help understand care plans if there are language barriers.
  • Being involved in their treatment, asking the doctor any questions they may have.
  • Using eyeglasses and hearing aids to promote good vision and hearing.
  • Getting out of bed during the daytime. This includes sitting in a chair during mealtimes or walking when possible (with supervision, if necessary).

Medications to treat delirium

Medicines for treating delirium symptoms include antipsychotic drugs (to treat agitation and hallucinations and to improve sensory problems). These include: Haloperidol (Haldol®) Risperidone (Risperdal®) Olanzapine (Zyprexa®) and Quetiapine. Also used are other medicines including Benzodiazepines (these should be used only if the patient has alcohol or drug withdrawal).

Once symptoms improve, the patient should not stop taking medications suddenly. Instead, the dose should be gradually decreased. Consult with the doctor before the patient starts any medications.

What are the complications/side effects of the treatments for delirium?

Side effects related to antipsychotic drugs, especially for the elderly, include:

  • High illness and death rates
  • Stroke
  • Risk of developing higher than normal pulse rate with irregular heartbeats when given haloperidol through IV

Benzodiazepines may cause:

  • Drowsiness or increased agitation
  • Reduced control over your behaviors
  • Uncoordinated muscle movements
  • Falls

What is the prognosis/outlook for people with delirium?

  • Longer hospital stays
  • Medical complications such as pneumonia and pressure ulcers
  • Delirium that can last from several hours to several months

Death rate among older patients in the hospital with delirium is 22 to 76 percent. However, some patients recover completely with appropriate diagnosis and treatment. Lack of treatment can lead to stupor, coma, or death. Patients who are elderly and those who have HIV are less likely to fully recover.

How can delirium be prevented?

Things that might help in preventing delirium:

  • Having a clock and calendar nearby
  • Having lots of lighting during the day
  • Limiting medicines that may cause delirium or any extra medicines not needed
  • Drinking plenty of water and other fluids
  • Trying to walk or at least sit in a chair daily
  • Reporting to doctors and nurses any symptoms of an infection (cough, fever, pain, shortness of breath)
  • Family involvement in the patient’s treatment

Research Clinical trials

Research is being done on different medicines that can be used for treatment of delirium without negative side effects.


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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 7/25/2013…#15252