What is Covid delirium? 'Key symptom' in elderly coronavirus patients

4 February 2021, 13:54 | Updated: 4 February 2021, 15:27

The intensive care unit at St George's Hospital, Tooting
The intensive care unit at St George's Hospital, Tooting. Picture: PA

By Patrick Grafton-Green

A state of delirium, or heightened confusion, has been found to be common in elderly or frail people who are severely ill with Covid-19.

Although delirium is not uncommon in critically ill patients with similar respiratory illnesses, its prevalence among Covid-19 patients appears to be markedly higher.

Delirium has been linked to the development of dementia later in life, leading to concerns over its link to coronavirus.

Here we explore what Covid delirium is, what the implications of it are and what can be done about it.

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What is delirium?

Delirium is a sudden change in a person’s mental state which leads to them getting confused and being unable to think and speak clearly.

They may also hallucinate, become agitated or have mood swings.

What do we know about its prevalence in Covid patients

A new study by an international research team, published last month in The Lancet, looked at 2,088 patients in 69 intensive care units across 14 countries.

Brenda Pun, lead author of the study, said over a two week period 80% of patients were in a coma for seven days, while 55% had delirium for three days on top of that.

This is much higher proportion than doctors working on critically ill patients are used to.

Studies have shown about a third of people who are critically ill usually develop delirium.

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'Key symptom' in older patients

Last year, experts from King’s College London who run the Covid Symptom Study, found that coronavirus patients who were considered “frail” were three times as likely to become delirious.

Researchers looked at two groups aged 65 or over, publishing their results in the journal Age and Ageing.

The first was 322 patients who had tested positive for Covid-19 and been admitted to St Thomas’ Hospital in London

The second was made up of 535 users of the Covid Symptom Study app who reported testing positive.

Of those who ended up in hospital, they found on in five (18.9%) said delirium was their sole symptom.

Meanwhile many patients experiencing delirium did not report suffering the typical symptoms of cough and fever.

Dr Rose Penfold, an epidemiologist at King's, said “our results show that delirium is a key symptom" in older, frailer people.

What can be done?

Long-term studies over the last decade show that just one episode of delirium can increase the risk of developing dementia later in life.

The study published in The Lancet showed benzodiazepine use increased the risk of delirium by 60%, so using alternative drugs could reduce the risk.

Meanwhile having family visit a patient, even virtually, was found to reduce the risk by 30%.

The paper concluded that the findings “presented an opportunity to reduce acute brain dysfunction in patients with Covid-19.”

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