A drug used by vets as a sedative for dogs could save thousands of hospital patients from suffering distressing post-surgery delirium.
It is estimated that between ten and 50 per cent of patients fall victim to the condition following a major operation, with over-65s particularly at risk.
Symptoms range from the relatively mild, such as a person not knowing their name or where they are, to the more severe, including aggressive behaviour towards medical staff, hallucinations or delusions, such as believing that people wish to harm them.
A drug used by vets as a sedative for dogs could save thousands of hospital patients from suffering distressing post-surgery delirium (stock photo)
Post-operative delirium usually strikes within the first two days of a person waking from general anaesthetic, and can prolong hospital stay and delay recovery.
It is estimated to cost the NHS tens of millions of pounds a year, with patients having to stay longer in hospital, taking up desperately needed beds.
A 2015 review of the effects of delirium on the NHS estimated that each case costs an additional £1,275.
Now, a British-Chinese study has found that giving patients a low dose of dexmedetomidine, a drug commonly used as an intensive-care sedative and in veterinary medicine as an anaesthetic, during surgery, can reduce the prevalence of delirium by up to 65 per cent.
The study involved 700 patients, aged 65 or older, who were about to undergo major surgery at Peking University First Hospital in Beijing.
After receiving the same general anaesthetic ahead of the operation, half of the study group received a low dose of dexmedetomidine about an hour after the operation, while half received a placebo salt-water infusion.
They were then assessed for symptoms of delirium every day for a week after their procedure.
The results revealed that nine per cent of patients who received the sedative developed delirium, compared to nearly one in four patients in the placebo group – 23 per cent.
Post-operative delirium usually strikes within the first two days of a person waking from general anaesthetic, and can prolong hospital stay and delay recovery
The patients given the sedative also had fewer post-operative complications than the placebo group, and were discharged from hospital earlier.
Due to the low dose, the drug did not cause ‘significant’ sedation and caused no other adverse side effects.
Anaesthetist Professor Daqing Ma of London’s Imperial College, who co-led the study, believes the sedative may help the brain ‘recover and reset’ after surgery.
Prof Ma said: ‘Delirium is a huge challenge for the medical community – and incredibly distressing for patients and their families.
‘In many cases, patients do not understand where they are, what is happening, and become very upset.
‘Hospital staff have been injured by delirious patients becoming aggressive. However, we have no treatment options available for this condition.
‘The causes are unknown, but one theory is that major surgery can trigger inflammation throughout the body, which in some cases can spread to the brain.
A study found that giving patients a low dose of dexmedetomidine, a drug commonly used as an intensive-care sedative and in veterinary medicine as an anaesthetic, during surgery, can reduce the prevalence of delirium by up to 65 per cent
‘The risk of the condition increases with age, and it seems to strike more often when patients undergo major, lengthy operations.
‘It can last from a few hours to a couple of days, and some research suggests that it may be linked to an increased risk of elderly patients later developing dementia.’
Scientists are unsure exactly how the sedative achieves the effect, said Prof Ma.
‘Previous studies have shown that patients who struggle to sleep after their operation – perhaps because they are in pain or on a busy, noisy ward – are at increased risk of delirium.’
He added that the sedative dexmedetomidine seems to not only trigger sleep, but actually mimics the natural ‘resetting’ state the brain enters during sleep.