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The 5th National Audit Project (NAP5) of the Royal College of Anaesthetists and the Association of Anaesthetists of Great Britain and Ireland into accidental awareness during general anaesthesia (AAGA) yielded data related to psychological aspects from the patient, and the anaesthetist, perspectives; patients' experiences ranged from isolated auditory or tactile sensations to complete awareness. A striking finding was that 75% of experiences were for <5 min, yet 51% of patients [95% confidence interval (CI) 43-60%] experienced distress and 41% (95% CI 33-50%) suffered longer term adverse effect. Distress and longer term harm occurred across the full range of experiences but were particularly likely when the patient experienced paralysis (with or without pain). The patient's interpretation of what is happening at the time of the awareness seemed central to later impact; explanation and reassurance during suspected AAGA or at the time of report seemed beneficial. Quality of care before the event was judged good in 26%, poor in 39%, and mixed in 31%. Three-quarters of cases of AAGA (75%) were judged preventable. In 12%, AAGA care was judged good and the episode not preventable. The contributory and human factors in the genesis of the majority of cases of AAGA included medication, patient, and education/training. The findings have implications for national guidance, institutional organization, and individual practice. The incidence of 'accidental awareness' during sedation (~1:15,000) was similar to that during general anaesthesia (~1:19,000). The project raises significant issues about information giving and consent for both sedation and anaesthesia. We propose a novel approach to describing sedation from the patient's perspective which could be used in communication and consent. Eight (6%) of the patients had resorted to legal action (12, 11%, to formal complaint) at the time of reporting. NAP5 methodology provides a standardized template that might usefully inform the investigation of claims or serious incidents related to AAGA.

Original publication




Journal article


Br J Anaesth

Publication Date





560 - 574


awareness, consent, patient experience, sedation, Anesthesia, General, Anesthesiology, Communication, Conscious Sedation, Health Care Surveys, Humans, Informed Consent, Intraoperative Awareness, Ireland, Medical Errors, Memory, Physicians, Quality of Health Care, Stress Disorders, Post-Traumatic, Surveys and Questionnaires, United Kingdom