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Information for carers about delirium

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What is delirium?

Delirium is an acute confusional state which may occur as a complication of a medical illness or after undergoing surgery. It is a temporary condition which will improve once the cause or causes are identified and treated. Delirium is not the same as dementia although people with dementia are more likely to develop delirium when they are ill. Delirium is not a mental illness although the symptoms may be similar.

Patients with delirium have difficulty concentrating, become confused (disorientated), and may have hallucinations. They may be hyperactive and agitated (which can be frightening to those around them) or they may be apathetic and withdrawn. These changes come on over a short period of time (usually hours or a few days) and tend to fluctuate in severity during the course of the day, often being worse at night (this is often referred to as ‘sundowning’). If you notice a change in your relative’s or friend’s behaviour please notify a member of staff.

Unfortunately, because they tend to be frail and often have a background of dementia, people who develop delirium do not always fully return to their previous level of functioning once the cause(s) of the delirium have been treated.

Who is at risk of developing delirium?

Delirium is more likely to occur in:

  • Older people (risk increases with increasing age over 65 years)
  • People with dementia or who have had delirium before
  • With any acute illness (but is more likely the more severe the illness)
  • In people with a fractured hip

Let the staff know if the patient has had an episode of delirium before or usually has memory problems, both of these make it more likely that someone will develop delirium and so the staff can try to reduce the chance of this happening.

What causes delirium?

  • Infection
  • Side effects of some medications
  • Dehydration
  • An imbalance of natural chemicals in the body (salt and calcium)
  • Suddenly stopping/ withdrawing some drugs or alcohol
  • Uncontrolled pain
  • Heart disease (for example heart attack, heart failure)
  • Lung disease (for example pulmonary embolism, low oxygen levels in blood)
  • Stroke
  • Epileptic seizures

Delirium often has more than one cause.

Delirium can be made worse by impaired eyesight or hearing, constipation, pain, poor nutrition and an unfamiliar environment.

How is delirium managed?

The doctors and nurses will do tests to find the underlying cause or causes and will then start appropriate treatment, for example antibiotics for infection. Special nursing techniques are aimed at optimising comfort and minimising confusion, disorientation and agitation. It is particularly important to maintain adequate food and fluid intake. Rarely (for example when the patient is a danger to themselves or others) sedation may be necessary on a short term basis whilst the cause of the delirium is being treated.

Once the cause or causes for delirium are treated it often takes some further time for the delirium to resolve (think of this as being like ‘jet-lag’ – when you return from holiday and set your watch to local time, it is a while before your body readjusts to normal). Sometimes symptoms of delirium can persist for a very long time after the cause or causes are treated.

What can you do to help?

  • Regular contact with familiar people and objects from outside the hospital is very important to patients with delirium. This helps to calm, orientate and reassure them.
  • Talk slowly and clearly about familiar, non-threatening topics and use a calm, reassuring tone of voice.
  • Remind them often where they are and what the time and date is.
  • Avoid long tiring visits, loud chatter and laughter and multiple visitors at any one time.
  • If they have hallucinations, explain that they are not real and be reassuring. If they insist that the hallucinations are real do not argue as this may make matters worse.

You may find that at times they are better and at other times more confused. This is a characteristic feature of delirium and will improve as the delirium resolves.

It can be distressing to have a relative or friend who is delirious. They may fail to recognise you or may behave out of character. Despite this it is important to continue visiting if you can and hopefully they will improve and respond to your visits.

As they recover the patient may recall that they were confused or ‘behaved oddly’. They will need an explanation as to why this was and reassurance that they are not ‘going mad’. If their memories of the delirium are frightening it is important to discuss these and provide reassurance by going through the events with them, explaining the nature and cause of their delirium. However, many people will not remember anything about their period of delirium; this is more likely to be the case if they have an underlying dementia.

You can discuss any difficulties with any of the ward staff who will be able to support you. Work together with the ward team to help your relative or friend to recover.

Further information

NICE CG103 Delirium – July 2010

A government issued NHS clinical continuing care guideline.

Delirium: prevention, diagnosis and management (opens in a new tab)

SIGN 157 - Risk reduction and management of delirium - March 2019

Scottish Intercollegiate Guideline.

Risk reduction and management of delirium (opens in a new tab)

European Delirium Association

An organisation for health professionals and scientists involved with delirium. The website also has links to other sites with information on delirium for patients and carers.

European Delirium Association (opens in a new tab)

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Cambridge University Hospitals
NHS Foundation Trust
Hills Road, Cambridge

Telephone +44 (0)1223 245151