Mild sedative may reduce delirium risk after operation

A mild sedative could reduce the risk of people experiencing delirium after an operation by up to 65 per cent, new research has found.

Up to one in three people who have a major operation may experience delirium, causing confusion and hallucinations.

The sedative may help the brain "recover and reset" after surgery, said the study published in the journal The Lancet.

"Post-operative delirium is a huge challenge for the medical community - and incredibly distressing for patients and their families," said co-lead author Daqing Ma, Professor at Imperial College London.

"However we currently have no treatments options available for this condition," Ma noted.

The causes of delirium are unknown, but one theory is that major surgery can trigger inflammation throughout the body, which in some cases can spread to the brain.

The risk of the condition increases with age, and it seems to strike more often when patients undergo major, lengthy operations.

In the new study, co-led by Professor Dongxin Wang at Peking University First Hospital in China, researchers assessed 700 patients age 65 or older who were about to undergo major surgery at the Beijing hospital.

Half received a low dose of a type of sedative called dexmedetomidine after the operation, as an infusion directly into a vein in their arm, while half received a placebo salt-water infusion.

The patients received the infusion of sedative or placebo around an hour after surgery, and for the next 16 hours.

This sedative, which is commonly used for medical procedures and in veterinary medicine, leaves a patient relaxed and drowsy, yet conscious.

Both groups received the same general anaesthetic before undergoing their operation. They were then assessed for symptoms of delirium every day for a week after their procedure.

The results revealed that nearly one in four patients in the placebo group - 23 per cent - developed delirium. However only just under one in ten patients - 9 per cent - who received the sedative developed the condition.

Scientists are still unsure how the sedative works, but one theory is it allows the brain to rest and recover immediately after surgery, explained Ma.

"There is still much more work to do around post-operative delirium, as we still don't fully understand what is happening in the brain, and why some patients are more at risk. However these findings suggest this sedative may be a potential method of preventing post-operative delirium in some patients," Ma added.

--IANS

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