Hospital delirium: what you need to know

Published August 2023 | 5 min read
Expert contributor Associate Professor Gideon Caplan, president of the Australasian Delirium Association
Words by Gina Flaxman

Hospital delirium is a serious condition and more common than you think. If you're caring for an elderly friend or relative, here’s what to look out for.

We’ve all occasionally experienced the feeling of waking up and feeling disorientated about where we are, particularly if we’re in an unfamiliar environment, like a hotel room. The sensation usually only lasts a few seconds. But for people in hospital, particularly people over the age of 65 who are already sick and may have more risk factors, that confusion can last longer and become a condition known as hospital-induced (or hospital-acquired) delirium. And it’s more common – and more serious – than you might think.

If you’re caring for someone who has dementia or another condition that affects their mental state, it can be harder to identify hospital delirium. “Delirium is acute confusion,” explains Associate Professor Gideon Caplan, president of the Australasian Delirium Association and director of post-acute care services and geriatric medicine at Prince of Wales Hospital. “It comes on over hours or days, whereas dementia comes on over months or years. Delirium is also associated with alterations in levels of consciousness – people can be drowsy or sleepy, or hyper-alert and more agitated. That doesn’t happen in dementia, except in the later stages.”

People with delirium have impaired memories and find it difficult to perform daily activities, like walking, in a similar way to people with dementia.

“In hospital-acquired delirium, the delirium is triggered by other conditions – medical illnesses, surgery, anaesthetic or just being in a strange environment,” says Prof Caplan.

What are the signs of delirium?

If you’re over the age of 65 or caring for someone elderly, it’s important to be aware of hospital delirium. Here are the signs Prof Caplan says to look out for.

• Confusion: You may suddenly become confused and disoriented and have trouble knowing where you are. You may also not recognise people or confuse them with others.
• Difficulty concentrating: You may be less able to pay attention to other people and their environment. This is why people with delirium often have trouble with activities like walking and, as a result, can fall over, which can be serious in elderly people. Your speech may also be mixed up and difficult to understand.
• Sudden changes in behaviour/personality: You may show unfamiliar swings in emotion, or easily become irritable, angry or upset.
• Fluctuating behaviour and consciousness: Your behaviour can fluctuate throughout the day from being restless and agitated to uncharacteristically quiet, withdrawn or sleepy.
• Hallucinations and delusions: You may see, hear or believe things that aren’t real, which can increase your agitation.

Prof Caplan says it can be quite confronting to see a loved one experiencing delirium. “It can make people act really abnormally,” he says. “You can have a lovely, gentle older lady suddenly start swearing at people or trying to harm herself.”

How common is hospital delirium?

While the condition can affect anyone, it’s more common in the elderly, says Prof Caplan. “In older people, whose brains are very vulnerable, even a minor illness can trigger delirium.”

Particularly in hospital and in intensive care wards, and Prof Caplan says delirium is estimated to affect about 80% of people – that’s two out of every three patients.

How long does delirium last?

Delirium can last anywhere from just a few minutes to weeks or, rarely, months. It has serious consequences as it can lead to other complications, like falls, longer hospital stays and ongoing cognitive impairment.

An analysis published in the Journal of the American Medical Association found delirium in elderly patients was associated with death or dementia, and another study found patients over 65 who had been diagnosed with delirium had a higher mortality rate than those who weren’t affected by the condition.

“Delirium accelerates the progression of dementia and it can also trigger dementia in people who didn’t have it before,” says Prof Caplan.

On top of the health effects, a study found the total costs of delirium in Australia in 2016 to 2017 were estimated at $8.8 billion.

While the statistics are scary, Prof Caplan says awareness of the condition has increased in the last few years. However, he adds delirium is often not diagnosed early enough and researchers still don’t fully understand what happens to the brain in delirium, with further research desperately needed.

How is delirium treated?

There are no specific treatments for delirium. Prof Caplan says doctors will screen for underlying medical problems or any factors that might be causing the condition and address them. “If the delirium is caused by an infection, we’ll treat the infection with antibiotics,” he explains. “If it’s being triggered by strong painkillers, we’ll reduce the dose of opioids. If there’s a metabolic problem, like an altered sodium or glucose level, we’ll address that.”

He says once these underlying issues are addressed, the delirium usually resolves itself.

While the patient has the condition, the Australasian Delirium Association recommends:

• keeping their hospital room as calm and quiet as possible, especially at night
• avoiding moving them between rooms as much as possible
• allocating someone to stay with them.

Prof Caplan says delirium is a medical emergency and it’s important to be treated as soon as possible. This means going to the emergency department if you’re at home and a loved one starts to become confused or, if they’re in hospital, alerting the staff as they may not be aware of it. “You’ve got to let the staff know that this is not their usual behaviour,” he says.

Can delirium be prevented?

According to studies, approximately 30 to 40% of delirium cases are preventable, which is why prevention is the most important part of any delirium strategy. In fact, a recent project to help develop delirium-prevention strategies in hospitals, in partnership with La Trobe University, has decreased hospital-acquired delirium by 18%.

Prof Caplan says there are simple steps loved ones and hospitals can take.

“These are things like making sure people have a good night’s sleep, making sure they stay hydrated and well nourished, and their sensory systems are working properly – their glasses are clean, their hearing aids are working,” he says. “You’ve got to make sure people have access to the aids they need and that people communicate with them, so they understand what’s going on.”

How to care for someone who has experienced hospital delirium

When the person is released from hospital, Prof Caplan says it’s important to help them return to normal and gently reorient them if they’re confused about their environment. You should try to make sure they eat well, exercise, stay hydrated and take their medications.

“You also need to be aware that once you’ve had delirium, you can get it again more easily, so it’s important to watch out for the signs,” he adds.

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