title: Awareness with recall during general anesthesia: incidence and risk factors.
abstract: We studied the associated factors and incidence of awareness during general anesthesia and the nature of subsequent psychiatric disorders. Patients older than 12 yr undergoing surgery under general anesthesia in a secondary care hospital during 1 yr were included in the study. The doses of anesthetics were calculated for the patients with and without awareness. There were 4818 operations under general anesthesia; 2612 (54%) patients were interviewed. Ten (0.4% of those interviewed) patients were found to have undisputed awareness, and there were nine (0.3%) patients with possible awareness. The doses of isoflurane (P < 0.01) and propofol (P < 0.05) were smaller in patients with awareness. Five patients with awareness underwent a psychiatric evaluation. One patient experienced sleep disturbances afterward, but the other four patients did not have any after effects. In conclusion, awareness is a rare complication of general anesthesia associated with small doses of anesthetics.
  
  
  CONCLUSIONS
  In an interview of 2612 patients after general anesthesia, 10 (0.4%) patients with awareness and 9 (0.3%) patients with possible awareness were found. A predisposing factor was small doses of the principal anesthetic. In a psychiatric interview, a large proportion of the patients with awareness were found to have suffered from depression in the past.
authors.affiliation: Department of Anaesthesia, Children's Hospital, Helsinki University Central Hospital, Finland. seppo.ranta@huch.fi
authors.forename: S O
authors.initials: SO
authors.lastname: Ranta
authors.forename: R
authors.initials: R
authors.lastname: Laurila
authors.forename: J
authors.initials: J
authors.lastname: Saario
authors.forename: T
authors.initials: T
authors.lastname: Ali-Melkkilä
authors.forename: M
authors.initials: M
authors.lastname: Hynynen
mesh_terms: D000328:Adult; D000368:Aged; D000768:Anesthesia, General / Q000009:adverse effects*; D001364:Awareness; D003430:Cross-Sectional Studies; D004325:Dreams; D005260:Female; D006801:Humans; D008297:Male; D011939:Mental Recall; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D016037:Single-Blind Method