Delirium

Delirium is confusion that begins suddenly and may vary from slight to severe within hours. People who have delirium cannot pay attention or think clearly.

Delirium is common among older people. About 10 to 20% of older people who are admitted to the hospital already have delirium. People over 85 are the most susceptible. Delirium is a common reason that family members of older people seek help from a doctor or at a hospital.

Delirium is never normal and always indicates a serious problem. People who have delirium need immediate medical attention. If the cause of delirium is identified and corrected quickly, delirium can usually be cured.

Causes

Delirium can be caused by many disorders and drugs and by stressful situations. These causes are especially likely to lead to delirium in people who have dementia.

Severe disorders can cause delirium in any person—young or old. Examples are infections, strokes, seizures, heart disorders (such as heart attack, abnormal heart rhythms, and heart failure), and diabetes that is poorly controlled. But in older people, relatively less severe disorders can cause delirium. For example, urinary tract infections are a common cause. Other examples are dehydration, a deficiency of vitamin B₁ or B₁₂, retention of urine, and constipation.

Certain drugs can cause delirium in any person. But older people are much more sensitive to many drugs. The list of drugs that can cause delirium in older people is long. The drugs that most commonly cause delirium are those that affect the way the brain functions, such as sedatives. Many nonprescription (over-the-counter) drugs, especially antihistamines, can also cause delirium in older people.

Delirium may result from withdrawal of sedatives that have been taken for a long time. Alcoholics may develop delirium if they suddenly stop drinking alcohol. This type of delirium is called delirium tremens (DT).

Stressful situations may be enough to cause delirium. When a stressful situation is combined with drugs or disorders, delirium is more likely to develop. For example, delirium is common after surgery (a stressful situation). The drugs used during surgery, the pain relievers used after surgery, and complications related to surgery make delirium even more likely.

People in intensive care units (ICUs) are particularly likely to develop delirium, mainly because the conditions there are stressful. In an ICU, hospital staff members must awaken people during the night to check vital signs or monitors and to give treatments. People in ICUs are usually able to sleep for only short periods of time. Loud beeping monitors, intercoms, voices in the hallway, or alarms may disturb sleep. People in ICUs must be isolated. Typically, the rooms have no windows or clocks to help people orient themselves. Thus, people in ICUs often cannot distinguish between night and day. Furthermore, most people in ICUs have serious disorders and take drugs, which can make delirium even more likely. The delirium that may develop in these people is sometimes called ICU psychosis.

For additional detail on this topic, see Theories for Why Delirium Affects Older People.

See the table Drugs That Can Cause Delirium.

Symptoms

Delirium begins suddenly. Usually, family members or friends notice that the person has become mildly or severely confused over a period of hours or a few days.

The level of confusion may vary. Often, confusion is worse at night. Confusion may worsen, then clear up during the next few hours, only to worsen again. A person may be sluggish one moment and alert the next. A person may be calm and focused, then agitated and distracted. Some people with delirium tend to be anxious and agitated. Very old people with delirium tend to become quiet and withdrawn. In them, confusion is only apparent when someone tries to rouse or talk with them.

People with delirium cannot pay attention, and their ability to do so may vary over minutes or hours. Thus, they do not understand what is happening around them. They become disoriented. They sometimes lose track of who they are, where they are, or what time or day it is. People with delirium cannot concentrate and have difficulty remembering. In conversation, they wander from topic to topic. Their speech may be slurred, rambling, or incoherent.

Many people with delirium do not sleep normally. They may fall asleep during the day, even in noisy places, and stay awake at night. If delirium becomes severe, people may see or hear things that are not there (hallucinate).

Diagnosis

When confusion begins suddenly, it is almost always delirium. Therefore, people who have recently become confused should be evaluated immediately for delirium. Such people are usually hospitalized so that the cause can be quickly identified and treatment can be started promptly.

Often, health care practitioners have trouble recognizing delirium. Delirium is especially hard to recognize in people who withdraw and thus do not communicate. Delirium is hard to recognize in people who have dementia because dementia can also cause confusion. In people with dementia, confusion develops over a period of months or years and slowly worsens. If a person with dementia develops delirium, the delirium is identified only if someone notices that the confusion has become decidedly worse over a period of hours to days.

Family members and caregivers can help by providing doctors with details about the person's change in mental function—how the confusion began and how quickly it progressed. The most important information a doctor can obtain is the perspective of someone who has known the person over time and who can describe the recent changes.

Family members and caregivers should also tell doctors about all the drugs and any other substances that the confused person may have taken. This list should include all nonprescription drugs and dietary supplements as well as any alcohol or illicit drugs used.

Doctors perform a physical examination. As part of the examination, the person may be asked questions to determine whether the main problem is an inability to pay attention, with the disorientation that results from it.

Samples of blood and urine are taken. Analysis of these samples may help doctors identify the cause of delirium. Sometimes more complex tests are needed. Computed tomography (CT) or magnetic resonance imaging (MRI) may be used to obtain images of the brain. A spinal tap (lumbar puncture) may be done to obtain a sample of the fluid that surrounds the brain and spinal cord (cerebrospinal fluid). Analysis of this fluid helps doctors rule out infections and bleeding. If the cause is thought to be a lung or heart disorder, a chest x-ray may be taken or electrocardiography (ECG) may be done to record the electrical activity of the heart.

While the person is hospitalized, doctors and other staff members watch for signs of withdrawal from alcohol and other drugs.

Prevention

When an older person is hospitalized, family members can talk to hospital staff members about what measures can help prevent delirium. The following measures may help:

• Keeping the person mobile. Getting the person out of bed and walking regularly is important. If the person cannot get out of bed, a physical therapist can help the person exercise or move in other ways.
• Keeping the person's mind active. Asking questions about the person's life, talking about current events, or reading to the person can help.
• Keeping the person oriented. People who wear glasses or use a hearing aid should have access to these items. Placing a clock and calendar in the room is useful. Explaining tests and treatments reminds people of where they are and why.
• Encouraging the person to do as many normal daily tasks (such as dressing) as possible. Doing daily tasks helps keep the person active and aware of the time of day and makes life seem more normal.
• Helping the person get a good night's sleep and making sure that light in the room is adequate during the day. Thus, the person can stay on a normal sleep cycle, get more restful sleep, and be better able to distinguish between night and day. Family members can talk to nurses about trying to reduce the number of loud noises (such as loud beeping monitors) and disruptions (such as giving drugs and checking blood pressure and heart rate) at night.
• Making sure the person drinks enough fluids and eats enough food. The person may need encouragement or help with drinking and eating.
• Asking staff members which drugs are being used and why. For example, family members can ask whether any of the drugs being used could make the confusion worse. If a sedative is being given to help the person sleep, family members can ask about using approaches that have worked at home, such as a glass of warm milk or a cup of herbal tea. If the person is in pain, family members should ask about more effective pain treatments.

Treatment

Once identified, the disorder causing delirium is treated. Prompt treatment of the disorder causing delirium usually prevents permanent brain damage and may result in a complete recovery.

During treatment, people with delirium may injure themselves, especially if they become very agitated or confused or if they hallucinate. Therefore, they should not be left alone. In the hospital, a full-time attendant may be needed to keep people with delirium safe and to care for them. People with delirium may need help and encouragement with getting in and out of bed, feeding themselves, and using the toilet. They may need someone to accompany them when they walk in the hallway. They may need reassurance because they are frightened. Family members may choose to provide this care, and nurses can help with it. Nurses can also notice signs of pain, the worsening of any other disorders, and other needs that may be hard to recognize because of the confusion.

At every opportunity, staff and family members should help orient a person with delirium to time and place. They should also explain what is going on around the person, including tests or treatments the person is about to receive.

Padded restraints are a last resort. Whenever possible, hospital staff members, with the help of family members, closely monitor the person instead of using restraints. However, restraints may be necessary to prevent falls or to prevent the person from pulling out medical devices, such as an intravenous line (IV), a catheter that drains urine from the bladder, or a feeding tube. Restraints are applied carefully, used only for a short time, and released at frequent intervals. But even then, restraints increase the likelihood that the person will be injured. Restraints can also upset the person and make the person more agitated. Health care practitioners constantly reevaluate the need for restraints. Then they can remove the restraints as soon as possible.

If a person with delirium has been taking drugs that may be making the delirium worse, doctors discontinue them if possible.

Sometimes a person is so confused, agitated, and frightened that a drug is needed. In such cases, antipsychotics are considered the best choice. These drugs help calm the person. Small doses are often effective. For some people, newer antipsychotics (such as olanzapine and quetiapine) are preferred to older antipsychotics (such as haloperidol). The newer antipsychotics have fewer side effects, such as muscle stiffness. When a person cannot tolerate the side effects of antipsychotics or when antipsychotics do not work, benzodiazepines, which are sedatives, may be used. Benzodiazepines sometimes used include midazolam and lorazepam. Although benzodiazepines can calm an agitated person, they cannot cure delirium and can make confusion worse. Therefore, doctors give the lowest possible dose and discontinue the drugs as soon as possible.

Outlook

If the disorder causing delirium is quickly identified and successfully treated, most people recover and can function as well as they did before delirium developed. However, any delay greatly decreases the chance of a full recovery. Even with prompt treatment, delirium may persist for many weeks or months, particularly in people who have dementia to some degree. Improvement may occur slowly. In some people, delirium persists and develops into a chronic disorder that resembles dementia.

People who develop delirium while in the hospital tend to stay in the hospital longer than those who do not develop delirium. They are also more likely to develop complications (such as pressure sores, urinary tract infections, and incontinence) and to fall and be injured.