A sudden change in an older person’s thinking or behaviour is called “delirium”. It is common and the brain is signalling that something has gone wrong within the body.
It can begin within hours. The person loses track of a conversation, has altered sleep patterns, becomes inattentive, does not know where he is or sees things that are not there. At 10 o’clock he may recognise everyone. By lunchtime he is trying to climb out of bed. That evening he seems nearly normal.
The fluctuation in consciousness is part of delirium. It comes and goes, sometimes within the same hour. Dementia usually develops gradually over months or years. The two can coexist as a person with dementia is especially vulnerable to delirium.
A doctor meeting an older patient for ten hurried minutes cannot understand his usual mind. His daughter knows that he pays his own bills, follows every cricket match and remembers which grandchild still owes him money.
Delirium can be noisy. The patient shouts, wanders, fights the blood-pressure cuff or swears at people he has never seen before. Of course, this attracts attention quickly.
The quiet version is easier to miss. He becomes sleepy, withdrawn, stops eating and mumbles replies. On a busy ward he may be called “settled” or, worse, “a good patient.” Meanwhile his brain is failing just as surely.
The cause may be a chest, urinary tract or skin infection. But antibiotics should not be prescribed by reflex every time an older person becomes confused. The patient still needs a proper history, examination and sensible investigations.
Other causes include dehydration, especially during heatwaves; low blood sugar; low oxygen; abnormal sodium; kidney or liver failure; stroke; pain; constipation; a bladder painfully full of urine; surgery; alcohol withdrawal; even the shock of an unfamiliar hospital. Often several small insults gang up on a vulnerable brain as the body rarely gives us the one tidy cause we would prefer.
Medicines such as sleeping pills, strong painkillers and antihistamines bought over the counter are common culprits in the elderly. Several tablets prescribed by several doctors, each reasonable on its own, could be troublesome together. A medicine that was safe when the kidneys worked well may become dangerous after dehydration or illness.
Abruptly stopping some medicines can make matters worse. However, new confusion deserves a careful pharmaceutical review, including prescription tablets, over-the-counter products, alcohol, cannabis and whatever is brewing in the bush-tea cup.
If an older person develops delirium, seek urgent medical help. Do not wait days to see whether he “settles.”
Do not assume he is stubborn, possessed, attention-seeking or finally “getting senile.” If he has diabetes, check his glucose if this can be done immediately. Bring his medicines or an accurate list. Mention any new drug, fall, fever, cough, poor fluid intake, reduced urination, vomiting, constipation or pain.
While help is being arranged, stay with him. Speak slowly. Tell him who you are and where he is. Bring his spectacles and hearing aids. A person who cannot see the room or hear the explanation becomes frightened very quickly. Do not surround him with six relatives asking his name, the date and who is prime minister.
Hospitals often place an older person in a strange bed, remove his glasses, wake him repeatedly, keep lights on at night, interrupt sleep, restrict movement and then act surprised when he loses his bearings. Hydration, pain relief, movement, daylight, sleep, familiar voices, bowel and bladder care, and removal of unnecessary tubes are part of treatment.
Some people remember insects crawling across the ceiling, nurses plotting against them or their children abandoning them in a strange building. The blood tests may return to normal while the fear remains. Recovery should include telling the patient what happened rather than pretending it never did.
The infection may improve while the mind takes days or weeks to clear. Indeed, some people never return completely to their usual level of function while others later need assessment for previously unrecognised cognitive decline.
The World Health Organization is now developing specific guidance on delirium in older adults, including medication safety and deprescribing. Delirium remains under-recognised even though it is linked to falls, longer hospital stays, loss of independence and death.
When I first worked in England as a junior doctor, I was surprised how often “acute confusional state” appeared at the top of an admission note. It was treated as a medical presentation in its own right, not shrugged off as old age.
The phrase stayed with me: if the confusion is acute, something new has happened until proven otherwise.
“Old” and “difficult” are not diagnoses.
When an older person changes overnight, ask what potentially reversible cause exists.
