Intraoperative awareness--comparison of its incidence in women undergoing general anaesthesia for caesarean section and for gynaecological procedures.

Background: Intraoperative awareness (IA) is diagnosed when patients can recall their surroundings or an event related to the surgery that occurred while they were under general anaesthesia. The female gender and Caesarean section are considered to be contributing factors. The aim of the present study was to analyse the frequency of IA in patients undergoing general anaesthesia either for Caesarean section or gynaecological procedures.

Methods: ASA I and II women were included into the study. Patients were randomly allocated to 4 groups: A, B and C included patients qualified for elective gynaecological surgery, and group D comprised Caesarean section patients. Premedication was not given. Group A received total intravenous anaesthesia with TCI, and groups B, C and D received balanced anaesthesia. The depth of anaesthesia was monitored with an AEP monitor. Blinded structured interviews were conducted 2 hours after anaesthesia and on postoperative days 7 and 30.

Results: 337 patients were enrolled into the study. 45 patients reported diverse sensations connected to the anaesthesia (Group A - 7 patients, B - 9 patients, C - 2 patients, D - 28 patients). There were mainly dream sensations, but IA was present in 3 cases. In all of the cases, IA was recognised during the first interview. One episode of awareness appeared in group B, and the other two appeared in group D. One Caesarean section was complicated by intraoperative haemorrhage. The patient from group B had similar sensations during previous anaesthesia. Two women enrolled in the study reported awareness in the past, which did not occur this time.

Conclusion: Awareness during general anaesthesia occurs occasionally. The frequency of occurrence in a group of patients undergoing general anaesthesia for uncomplicated Caesarean section is not higher than for other procedures. The anaesthesia for Caesarean section, as well as for other procedures, may be accompanied by pleasant dreams.