Delirium is a medical problem which can develop when people are acutely unwell and/or are undergoing medical treatment, such as surgery. Older people, especially those who have dementia, are more at risk of developing delirium at these times. Delirium is also common in people receiving palliative care, and children with fevers or after some anaesthetics. Although the cause is not always known, it is always a consequence of physical changes related to illness or its treatment (e.g. infection, pain, or the addition of medications).
Delirium causes changes to the person’s usual mental functioning. Its onset is rapid (hours or days). It is sometimes confused with other conditions (e.g. stroke, depression and dementia).
Delirium is a serious condition and, if not managed promptly, other complications can occur, such as falls, longer hospital stays and ongoing cognitive impairment. While delirium usually lasts for only a few days and can be reversed, delirium sometimes persists even after the underlying problems are treated.
In children, delirium due to fever usually happens at night, occurs during the early stages of their illness and is usually very brief. At present, little is known about how long delirium will last in children when it occurs due to other circumstances.
‘Acute confusion’ or ‘impaired cognition’ are other terms that might be used to refer to delirium. (1-3)
People who have delirium suddenly become confused, forgetful and less able to pay attention to others and their environment. They will have difficulty concentrating, and may be disoriented, easily distracted and unable to engage in conversation. They may also misinterpret situations, show unfamiliar swings in emotion and see, hear, think or believe things that are not real. What they say is often mixed up or makes only partial sense to others. For the person, it feels like being in a strange dream or nightmare. As the person with delirium has trouble understanding, communication will be more difficult than usual and the person may become frustrated or angry with you.
Behaviour can range from restlessness, irritability, combativeness and repetitive behaviours, to uncharacteristic quietness, sleepiness, or withdrawal. These behaviours often fluctuate during the day.
Though behaviour changes are similar in children, irritability, agitation, sleep wake disturbance and changing moods are more common. Like adults, children may experience hallucinations. (2-7)
How common is delirium?
Delirium is a common condition amongst older people in community, residential and acute care settings. Up to one third of older people have delirium when they are admitted to hospital, and from 33% to 92% of older people will develop delirium when they have surgery to repair their hip fracture. Though delirium occurs less often in older people living in the community, it is more common in people aged over 85 years. In residential aged care the rate of delirium can be high, often in association with pre-existing dementia. In Intensive Care Units about 2 out of every 3 patients will get delirium. Although delirium is common in older people and people receiving palliative care, anyone can become delirious when unwell.
Although children are at risk of delirium, there little research about how common it is. At present, studies suggest that about 10% of hospitalised children/adolescents and 17-66% of paediatric intensive care patients referred to inpatient psychiatry services suffer delirium.
Why do people get delirium?
Delirium is caused by an underlying acute medical/surgical/traumatic condition which requires treatment. Although we are still uncertain about why people get delirium, we do know that people are more at risk when personal factors create vulnerability (e.g. older age, illness and cognitive decline) and other factors or events occur to enhance this vulnerability (e.g. infections, dehydration, medication).
Factors which seem to make children more at risk of delirium include: young age, being male, pre-existing progressive cognitive impairment or intellectual disability, having pre-exisiting behaviour problems and carer anxiety or absence. Common factors that enhance vulnerability include sepsis, anaemia, hypoxia and trauma. Children are thought to be more vulnerable to delirium from fever and general anaesthesia than adults. (3, 11-13)
Is delirium the same as dementia or depression?
No. Delirium is also not a normal reaction to being unwell, being admitted to hospital or having surgery. It is not a normal change in mental function from ageing. It is important for the medical team treating the person to differentiate between a diagnosis of delirium, dementia and depression.
How is delirium treated?
Delirium is usually managed by firstly treating the cause. For example, if a urinary tract infection is causing delirium, antibiotics will be commenced; if dehydration is a cause, intravenous fluids may be given.
In addition, the following strategies may be used to help the person during their delirium:
Keeping the hospital room as quiet and calm as possible, especially at night.
Avoiding placing the person in a room near busy and noisy parts of the ward (e.g. nurses station)
Avoiding moving the person from one room to another.
Allocating someone to stay with the person.
Gently reminding the person where they are, why they are in hospital and what day/time it is.
Asking family and other familiar people to visit and sit with the person. For children, to be a constant presence who comforts the child.
If other calming strategies have not helped and the person is very distressed, sometimes medicines may be used for short periods of time to help calm the person.
What can you do to help?
My family member is going home and is still not back to normal. What should I ask healthcare staff?
It can be helpful to discuss:
What do family members say about being with someone during delirium?
It can be helpful to know what other family members have said about their experiences during delirium. Family members in research studies say they feel unprepared for the sudden way delirium appears. They say that being with someone during delirium is confronting, shocking, scary and distressing.
Family members of older people often describe the person as lost or absent during delirium, including how sad and distressing this is for them. They also say delirium is a contradictory experience as the body of the person remains familiar whilst the person they know is no longer contactable. As some family members have said;
... he’s not with us, his mind is not with us. Physically he is. (10)
… dad was a complete stranger. It was not dad anymore, it was a complete stranger. (10)
To family members, the way the person acts during delirium accentuates how different the person is and how lost the person they know has become. At the fore is the peculiar ways the person acts, often their loss of self-control and their presence in another world; behaviours that are unexpected, bizarre, and shocking; or in contrast, closed, quiet and distant. Hallucinations suggest the person inhabits an inaccessible other world which is perceived by the person as real. Family members say;
... It was as if she had her own video running in her head that we couldn’t see, but she was interacting with this mental image and you know, sometimes she’d be laughing and other times she’d be angry. And it’s hideous to watch. It’s really terrible. (10)
Being with the person and waiting for them to return to their prior self is a worrying time and is hard to bear.
… apart from a few, a few lucid moments he’s been troubled and confused and hallucinating the whole time. The whole time. (10)
Whilst delirium is present family members describe having difficulty understanding what has, and is, happening. They can feel unsure about what to do to help, and feel helpless to control what the person says and how they act. They are concerned about future care needs and how these might be addressed. They can fear the person has developed dementia, brain damage, “gone mad”, or is close to death. (4, 14-18)
What can I do to help myself?Try not to become upset or be offended by what the person says or does whilst delirious. During delirium the person is not thinking clearly and is not themselves. They may not remember what they have said or done after delirium passes.
Will the person remember what happened during their delirium?
After delirium passes, some older people are able to recall their experience. Some find remembering helpful, aiding their understanding about what happened, and providing a sense of relief. However, a range of disturbing emotions can also be felt when they remember their actions and words while delirious. Some express feelings of belittlement, guilt, shame, embarrassment, humiliation, or remorse. At times they explain their actions as being out of character, or ask for forgiveness. Encountering memories of delirium can mean confronting the reality of their experience, or viewing the episode as a dissociated event in their lives. Some older people want to forget the episode, or are hesitant to discuss their experience, seeming to play down their unusual experiences and discouraging discussion. Discussing their experiences can risk being viewed as foolish. At times denial, embarrassment or dismissal of their experience is revealed through incongruent laughter or minimisation of what occurred. These reactions suggest you may face unexpected rejection or dismissal when wanting to talk about delirium with the person. Although delirium has passed, older people who have experienced delirium may feel vulnerable and in need of continued family understanding and support.
Though family members are relieved when delirium subsides, some find their relationship has been irrevocably changed by the way the person acted. In addition, knowing more about what happened during their delirium than the person may be a burden. (5,14,19-25)
Can I help prevent delirium from happening again?
Yes, you can help. It is important to focus on and minimise the risk factors for delirium for and with the person, including;Preventing, identifying and seeking early treatment health problems, such as urinary tract infection, pain, dehydration and constipation.
Information about delirium
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