Friday, October 9, 1998 Published at 01:05 GMT 02:05 UK
Operation blunders of sleepy surgeons
Surgeons were tested on a computer simulator
New research has revealed just how badly surgeons' performances suffer when they go without sleep.
The study, published in The Lancet medical journal, shows sleep-deprived surgeons make far more errors and take much longer to carry out a procedure than their colleagues who have had a restful night.
The procedure involved complex two-handed movements and the operation of a foot pedal.
The computer monitored the surgeons' performances, tracking the precise movements of the instruments, measuring how well they hit the targets they were after and the length of time it took.
The surgeons were assessed after an undisturbed night, a night during which they were woken three times and a night with no sleep.
The doctors who stayed up all night made 20% more errors and took 14% longer to complete the surgical tasks than those who had slept through the night.
The investigators also found that lack of sleep resulted in increased levels of stress, which affected the surgeons' dexterity.
Co-author Professor Ara Darzi, from the Imperial College School of Medicine, St Mary's, London, says the research did not imply sleep-deprived surgeons were dangerous.
"We're just saying that their performance is significantly affected.
"We are trying to optimise the performance of surgeons and we have identified one of the things that will do that - and that is a good eight hours sleep or a break from what they do."