Investigators surveyed 82% of the UK’s consultant anaesthetists – 7,125 in all – asking them to report any cases of accidental awareness in the past year. Out of nearly 3 million operations in 2011 there were 153 reported cases.
Most of these patients either came round too soon from general anaesthetic or took too long to go under. A third – 46 in total – were conscious throughout the operation. According to the anaesthetists, very few patients suffered any pain or distress as a result of the experience.
The researchers from the Royal College of Anaesthetists and the Association of Anaesthetists of Great Britain and Ireland say their preliminary findings, published in the journal Anaesthesia, should be reassuring for patients.
Prof Tim Cook, co-author of the study and a consultant anaesthetist in Bath, said: "Most of the cases involved the patient being aware during induction when they are being sent off to sleep or after the operation itself has finished.
"They might feel some awareness of tugging or hear some noises.
"Few anaesthetists that we surveyed said their patients complained of pain or distress or made a formal complaint."
Prof Cook said it was a fine balance trying to ensure that a patient was suitably sedated.
"You want to make sure that they are under but you don’t want to give them too much because that is dangerous in itself."