Mental Confusion (Delirium), ASCO's curriculum

This section has been reviewed and approved by the PLWC Editorial Board, 05/05

Delirium is a common problem for patients with cancer, especially those with advanced cancer or those at the end of life. It is present in 15% to 30% of patients who are hospitalized for cancer and in up to 85% of those in the final weeks of life. Delirium can be very stressful on the patient and his or her family members. It can also interfere with other symptoms and treatments for the cancer, including the treatment of pain.

It is important to clarify the difference between delirium and dementia, since they can have some of the same symptoms. Patients with delirium develop it quickly, become agitated, and can go in and out of consciousness over time. Memory problems are usually short-term. Dementia develops more gradually, and effects on memory and consciousness are more permanent.

There are three types of delirium: hypoactive (lethargic, confusion, sedation); hyperactive (agitated, delusions, disoriented); and mixed. More than two thirds of all delirium is hypoactive or mixed.

Features of delirium can include:

  • Depression
  • Delusions or hallucinations
  • Restlessness, anxiety, sleep disturbance, irritability
  • Altered level of consciousness or awareness
  • Shortened attention span
  • Memory problems
  • Disorganized thinking and speech
  • Disorientation
  • Reversing day and night
  • Difficulty writing, drawing, or finding words
  • Personality changes


To plan treatment for delirium, doctors may do a physical exam, or take some blood tests. They will also do a mental exam, using tests that check motor skills, memory, and attention level.


Finding the cause of delirium is
often important, in case it can be treated or reversed. The direct causes of delirium are usually a brain tumor or cancer that started somewhere else and has spread to the brain. Other causes:

  • Brain tumor or other cancer spread to the brain
  • Medicine
  • Withdrawal from medicine
  • Electrolyte imbalance
  • Organ failure
  • Infection
  • Other brain disorders
  • Lack of oxygen in the blood

People with advanced cancer are often taking many medications, and have more than one condition relating to age or cancer. Delirium can have many causes, and can be started by only a slight change in medication or the patient's condition.

Managing delirium

The main goal in managing delirium is keeping each patient comfortable and safe. These may help:

Environment. A quiet, well- lit room, familiar people and objects, and a visible clock and wall calendar may help a patient experiencing delirium.

Medicine. In some cases, antipsychotic or other types of medication can help bring a patient out of delirium. These drugs can also have significant side effects.

Delirium at the end of life

Treating delirium is a delicate issue, for patients, family and friends, and medical professionals. Some feel the hallucinations that come with delirium at the end of life are part of the dying process and should not be treated. For example, a patient who sees dead family members welcoming them to heaven can be a great comfort. However, delirium can switch with very little warning from a peaceful, pleasant experience into a frightening one, and in these cases treatment might be helpful.

There is also a method called controlled sedation, which is giving a patient drugs that put them into a deep sleep. At the end of life, this can make the patient more comfortable, but may also leave family members with a premature sense of loss. Sedation is not intended to speed up death, but to provide comfort to a patient at the end of life. Even with sedation, a patient may experience moments of clarity and be able to talk with family members.

Each decision about managing delirium is individual. It is important for patients and their family members to talk with their doctors and understand all the treatment options available.

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