It’s every patient’s nightmare - to feel the cut of the scalpel, to be totally aware of what the surgeons are doing to you, but unable to move or speak to let them know you are suffering.

But New Scientist magazine reported on Wednesday that a monitor which has undergone large-scale international trials may help reduce by 80 percent the number of people who experience “awareness” during surgery.

According to the New Scientist, around one in 1,000 surgery patients has some recollection of an operation carried out under general anaesthesia. While some of those will only have a fleeting impression, up to half will have been acutely aware of the procedure, conversations between surgeons, and the pain.

Researchers conducted a trial with the device - called a BIS monitor - on 2,500 patients in 24 hospitals in Australia, New Zealand, Britain and Hong Kong.

The BIS monitor detects electrical activity in the brain via a single electrode on the forehead and translates that into an index of awareness where a reading of 100 is awake and between 40 and 60 is the level at which more anaesthesia is recommended.

Preliminary results showed that eleven of the patients not using a monitor experienced awareness during their operations, compared with only two of those using the monitor, the New Scientist said.

Full results of the trial, run by Paul Myles of the Alfred Hospital in Melbourne and Kate Leslie of the Royal Melbourne Hospital, are expected to be published in the Lancet medical journal soon.

SOURCE: New Scientist, April 14, 2004.