title: Awareness in children: a secondary analysis of five cohort studies.
abstract: Five recent cohort studies have shown a frequency of awareness in paediatric anaesthesia of between 0.2% and 1.2%, but they were not individually large enough to identify risk factors. This study pooled raw data from these five studies to identify factors associated with awareness in children. The outcome of awareness was taken as the cases judged to be most likely awareness cases in each study. Logistic regression was used to identify awareness-associated factors. A combined sample of 4486 anaesthetics revealed 33 cases of awareness. Unadjusted analysis demonstrated weak evidence that nitrous oxide used as an anaesthetic maintenance adjunct was associated with awareness (OR 2.04 (95% CI 0.97-4.33), p=0.06), and some evidence that use of a tracheal tube was associated with awareness (OR 2.78 (95% CI 1.11-6.94), p=0.03). Multivariable regression analysis revealed that nitrous oxide maintenance and use of a tracheal tube were independently associated with awareness (nitrous oxide, OR 2.4 (95% CI 1.08-5.32), p=0.03; tracheal tube, OR 3.0 (95% CI 1.20-7.56), p=0.02).
authors.affiliation: Department of Anaesthesia, Royal Children's Hospital, Melbourne, Australia. andrew.davidson@rch.org.au
authors.forename: A J
authors.initials: AJ
authors.lastname: Davidson
authors.forename: K R
authors.initials: KR
authors.lastname: Smith
authors.forename: H J
authors.initials: HJ
authors.lastname: Blussé van Oud-Alblas
authors.forename: U
authors.initials: U
authors.lastname: Lopez
authors.forename: S
authors.initials: S
authors.lastname: Malviya
authors.forename: C F
authors.initials: CF
authors.lastname: Bannister
authors.forename: J L
authors.initials: JL
authors.lastname: Galinkin
authors.forename: W
authors.initials: W
authors.lastname: Habre
authors.forename: C
authors.initials: C
authors.lastname: Ironfield
authors.forename: T
authors.initials: T
authors.lastname: Voepel-Lewis
authors.forename: F
authors.initials: F
authors.lastname: Weber
mesh_terms: D000293:Adolescent; D000768:Anesthesia, General / Q000009:adverse effects*; D018685:Anesthetics, Inhalation / Q000009:adverse effects; D002648:Child; D002675:Child, Preschool; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D058926:Intraoperative Awareness / Q000453:epidemiology / Q000209:etiology*; D007442:Intubation, Intratracheal / Q000009:adverse effects; D008297:Male; D011939:Mental Recall; D009609:Nitrous Oxide / Q000009:adverse effects
chemical_list: D018685:Anesthetics, Inhalation; D009609:Nitrous Oxide