Delirium

Delirium, also called an acute confusional state, is a sudden change in how someone's mind is working. It comes on quickly, often over hours or days.

A person with delirium may be confused, but they can also be sleepy or agitated, hold altered beliefs, or see hallucinations.

Delirium is often triggered by:

• illness
• the side affects of medication
• an injury
• having surgery

People with delirium may have a number of symptoms, including:

• being confused (or more confused than normal)
• being sleepy and less responsive
• being very agitated or restless
• a change in sleeping pattern (like being awake at night and sleeping during the day)
• suspiciousness or a loss of trust
• seeing or hearing things that aren't real

Sometimes these symptoms are worse in the evenings or overnight.

Most delirium lasts a few days, but sometimes it goes on for weeks or even months.

Delirium can carry on even after every trigger has been dealt with. If that happens, you should keep getting supportive care and help. In other cases, the delirium slowly gets better.

Sadly, not everyone returns to the same level of mental function they had before the delirium.

Delirium happens when something changes the way the brain works. Several things can trigger that change, including:

• an infection, such as a urinary tract infection (UTI) or a chest infection
• prescription medicine, because delirium can be a side effect or can come from stopping the medicine suddenly
• dehydration
• constipation
• injuries (a hip fracture, for example)
• a low blood sugar level, for example in people with diabetes
• alcohol withdrawal
• surgery
• severe psychological stress

Anyone can get delirium, but some things make it more likely. These include:

• being over 65
• having dementia
• being frail
• hearing or sight loss
• having had delirium before
• alcohol misuse

Delirium is one of the most common medical emergencies. It's found in around 1 in 7 adults in hospital and about half of patients in intensive care.

Relatives and carers are often the first to notice delirium. What they pick up on is a change in the person's normal mental function.

Doctors and other health staff identify delirium by looking at its core symptoms. They often do this with a test called the 4A's test, or 4AT. It's a quick test in which the health professional asks the patient a few orientation questions, such as what year it is. They may also ask the person to say the months of the year in reverse order.

The test helps show whether the patient's mental function is different from normal.

Delirium is usually caused by one or more triggers, so treatment begins with finding out what they are. Once the triggers are known, doctors and other health professionals can treat them as well as they can. If the person has a chest infection, for example, treating that infection would help the delirium.

More than one trigger is often at work. A person with a chest infection may also be dehydrated, or may have a low blood oxygen level. Either of these can set off delirium too, or make it worse.

Treating the symptoms of delirium is another part of care that matters. Many people with delirium become distressed because they feel disorientated. They may also become paranoid, see or hear things that aren't there (hallucinations), or feel they're losing control.

These symptoms can get better when people around the person reassure them again and again and explain carefully what's happening. Occasionally, doctors and other health staff may use anti-psychotic drugs or other treatments.

Once the triggers and symptoms of delirium have been dealt with, the next step is to help the person recover. The aim is to get them back to their usual self through:

• rehabilitation
• engagement with them
• hydration
• nutrition

Delirium can lead to a few complications, including:

• immobility
• falls
• pressure sores
• isolation

When you're caring for someone with delirium, a few things help:

• Keep their hearing aids, glasses and dentures within reach
• Be gentle and friendly. Smile and offer reassurance
• Talk to the person and keep them informed, using short, simple sentences
• Try to make sure someone they know well is with them
• Keep a calendar or a clock (or both) where they can see it
• Bring in some familiar things from their home to keep by the bedside, such as photographs
• If it's safe to do so, help them to eat and drink (check with the care staff if you have any doubts)

Caring for someone else can be stressful. Try to make sure you are sleeping and eating, and try to build a network of people who can support you.

After you recover from delirium, your risk of dementia is higher than before. If you already live with dementia and develop delirium, you may be worse afterwards than you were before it.

Some people go through real distress during delirium, and they may develop post traumatic stress symptoms later. These include intrusive memories of the delirium, as well as symptoms of anxiety and depression.

Delirium is very common in people in their last days of life. It affects up to half of people in this situation.

The delirium needs to be recognised, and where possible, you should look at whether any easily treatable triggers are behind it. Even so, the main focus of care is managing the symptoms.

Read more about what happens when someone's dying

Delirium comes on over hours or days, and in most cases it gets better within a few days. Dementia develops over months or years and is nearly always irreversible.

The symptoms of delirium and dementia can sometimes overlap. Disorientation, for example, is usual in both conditions. But people with delirium are more likely to:

• be drowsy
• be agitated
• be paranoid
• have hallucinations

The 2 conditions often exist together, especially in older people. People with dementia are much more likely to develop delirium. In hospital, at least half of older people with delirium will also have dementia.