Delirium (confusion)

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A sudden change in a person’s mental state could be due to delirium. Delirium can lead to increased confusion, disorientation, or difficulty with concentration, and can come on very quickly. It often occurs when someone is medically unwell and can be caused by underlying problems like infections, pain or dehydration.  

Delirium can have a significant impact on the way a person behaves and functions, especially if they also have dementia. It can be very distressing both for the individual and the people who are caring for them.   

Delirium and dementia

Delirium is a condition that may co-exist with dementia. However, it is sometimes difficult to recognise in people with dementia because it has similar symptoms such as confusion and difficulties with thinking and concentration. 

Delirium often has an underlying cause, such as an infection. It can last for a few days, weeks, or even months, but it may take longer for people with dementia to recover. 

In hospitals, approximately 20-30% of older people on medical wards have delirium at some point, and up to 50% of people with dementia. Between 10-50% of people having surgery can develop delirium.  

Older people with delirium and dementia have been found to need longer stays in hospital, be at increased risk of complications such as falls, accidents or pressure sores, and be more likely to be admitted into long-term care.  

In extreme cases, the condition that is causing delirium can be fatal, so it’s vital that the person receives medical assistance as soon as possible. 

Symptoms of delirium

There are two types of delirium.

  • Hyperactive delirium causes increased confusion that fluctuates throughout the day. People may feel agitated or restless 
  • People with hypoactive delirium may feel more sleepy and be less responsive than usual 

Other symptoms of delirium include seeing things that are not there, or vivid dreams, difficulty in focusing their attention, and problems following conversations. 

People who have had delirium say they:

  • felt unsure of their whereabouts
  • were worried that other people were trying to harm them
  • felt afraid, irritable, anxious or depressed
  • felt slow and sleepy
  • felt agitated and restless
  • had vivid dreams that continued when they woke up
  • found it hard to follow what was being said
  • found it difficult to speak clearly
  • saw and heard things that were not there

Who is more at risk of delirium?

  • People with dementia
  • People who are dehydrated or have a poor appetite
  • People with an infection (although low level infection may not show up on tests)
  • People who are constipated or have urine retention
  • Older people
  • People who have had surgery, particularly hip surgery
  • Older people taking multiple medications
  • People with sight and hearing difficulties
  • People who are nearing the end of their life
  • People who are in pain
  • People in an unfamiliar or distressing environment

In this video our Chief Admiral Nurse and CEO, Hilda Hayo, provide some tips about what delirium is, how you can recognise it, what causes it, and what you can do about it.

What to do

If you think someone is experiencing delirium, contact their GP for an urgent assessment and adviceIf a GP is unavailable and the confusion or disorientation has come on suddenly or seems severe, contact the duty doctor who, if necessary, will arrange an ambulance. 

How is delirium treated?

There is no treatment for delirium itself, but treating the underlying cause often helps the person recover. For example, if the person has an infection, antibiotics might be needed, or if they are in pain, the doctor might suggest taking painkillers.  

The doctor may request blood and urine tests to help them decide on appropriate treatment. They may also want to review any medication that could be contributing to the delirium.  

Sometimes, there is no obvious treatable cause, and the person may simply need time and rest to recover. 

If the person is very confused and distressed, they may be given sedative medication to calm them. However, these drugs can make delirium worse in some people, so they are generally only used in severe cases, for instance if the person is at risk of harming themselves or someone else. 

There is some evidence that delirium can be prevented by reducing the risk of potential causes, like constipation, dehydration and infection. Ensuring the person stays well hydrated, practises good hand hygiene, and follows any advice they’re given about wound care and medical devices (such as urinary catheters) may help. If possible, you should also avoid the person moving beds or wards in hospital. 

What can I do to help someone with delirium?

If a person is experiencing delirium, there are some things you could do to make the situation a little easier for them: 

  • Keep calm and reassure the person 
  • Use short, simple sentences when talking 
  • Look for clues that they are in pain, or ask them if possible 
  • Make sure there’s nothing affecting their senses, such as not wearing their glasses or a flat battery in their hearing aid 
  • Show them favourite photos and objects to distract them and provide familiarity 
  • Remind them of the time and date (more than once, if necessary) 
  • Help them find the toilet if they need it 
  • Avoid too much stimulation like having lots of people around if possible 
  • Keep a low light on at night 
  • Avoid disagreeing with the person too much. Change the subject if they express ideas that seem odd to you 
  • Offer them drinks to maintain hydration 

Sources of support

Dementia UK leaflet on Staying healthy

Dementia UK leaflet on False beliefs and delusions

Dementia UK leaflet on Changes in perception

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