title: [A retrospective study on awareness in 1922 cases during induction of general anesthesia].
abstract: BACKGROUND
  There are some reports on the incidence of awareness during general anesthesia that is usually stable at the maintenance period. The aim of this study is to evaluate the incidence of awareness during the induction period of general anesthesia in which the effects of anesthetics are unstable.
  
  
  METHODS
  The research-nurses interviewed the patients, who had undergone general anesthesia, on the awareness during anesthesia within a week after operation. The patients were excluded from the study if they were in deep sedation or unconscious because of the medical reasons. We defined the induction period from the administration of hypnotic drugs to the tracheal intubation.
  
  
  RESULTS
  Seven cases with ages from 20 s to 70 s out of 1922 cases were identified as the residual awareness cases during the induction period. Six cases were managed with low concentrations of inhalation anesthetics after injection of intravenous hypnotics. The incidence was lower, but not significant, if they were managed with total intravenous technique. The BIS values were above 60 in all these cases if the monitor was attached.
  
  
  CONCLUSIONS
  The incidence of awareness during the induction was 0.36%. We have to pay more attention to the disappearance of the hypnotic effect at the induction period.
authors.affiliation: Department of Anesthesiology, Tokyo Women's Medical University, Tokyo.
authors.forename: Takaaki
authors.initials: T
authors.lastname: Chino
authors.forename: Osamu
authors.initials: O
authors.lastname: Nagata
authors.forename: Masami
authors.initials: M
authors.lastname: Naitou
authors.forename: Haruyo
authors.initials: H
authors.lastname: Nagao
authors.forename: Minoru
authors.initials: M
authors.lastname: Nomura
authors.forename: Makoto
authors.initials: M
authors.lastname: Ozaki
mesh_terms: D000328:Adult; D000368:Aged; D000768:Anesthesia, General; D018685:Anesthetics, Inhalation; D001364:Awareness; D006801:Humans; D007442:Intubation, Intratracheal; D008875:Middle Aged; D012189:Retrospective Studies
chemical_list: D018685:Anesthetics, Inhalation