title: Effects of increasing sevoflurane MAC levels on mid-latency auditory evoked potentials in infants, schoolchildren, and the elderly.
abstract: BACKGROUND
  Detection of mid-latency auditory evoked potentials (MLAEPs) is a technology to monitor central nervous structures. As seen in adults and children, general anaesthesia influences the MLAEP latencies. MLAEP detection seems to be a promising tool to assess different levels of anaesthesia depth in adults and children.
  
  
  METHODS
  MLAEPs were recorded in 10 infants (2 months-3 yr), 12 schoolchildren (6-14 yr), and 10 elderly (75-89 yr) under general anaesthesia with increasing concentrations of sevoflurane at steady state. In addition, MLAEPs were detected before and after the application of sufentanil.
  
  
  RESULTS
  At all different ages, MLAEP latencies increased significantly with higher volume percentages of sevoflurane. These results were also detectable when MAC values of sevoflurane were compared with MLAEP peaks. An age-dependent effect could be displayed as elderly people need lower absolute sevoflurane concentrations to achieve the same MLAEP peak increase. Overall, the application of sufentanil under steady-state sevoflurane application at 1 MAC did not importantly affect the MLAEP latencies.
  
  
  CONCLUSIONS
  MLAEP latencies increase at the influence of sevoflurane in a dose-dependent manner and in relation to age. These results imply that MLAEP detection is a reasonable tool for monitoring hypnotic effects at all ages. Further studies are required to standardize MLAEP alterations related to effects of medication used for general anaesthesia at all different ages.
authors.affiliation: Department of Anaesthesiology, Klinikum Grosshadern, University of Munich, Munich, Germany. matthias.feuerecker@med.uni-muenchen.de
authors.forename: M
authors.initials: M
authors.lastname: Feuerecker
authors.forename: M
authors.initials: M
authors.lastname: Lenk
authors.forename: G
authors.initials: G
authors.lastname: Flake
authors.forename: V
authors.initials: V
authors.lastname: Edelmann-Gahr
authors.forename: D
authors.initials: D
authors.lastname: Wiepcke
authors.forename: C
authors.initials: C
authors.lastname: Hornuss
authors.forename: M
authors.initials: M
authors.lastname: Daunderer
authors.forename: H-H
authors.initials: HH
authors.lastname: Müller
authors.forename: G E
authors.initials: GE
authors.lastname: Kuhnle
mesh_terms: D000293:Adolescent; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D000768:Anesthesia, General / Q000379:methods; D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004305:Dose-Response Relationship, Drug; D005072:Evoked Potentials, Auditory / Q000187:drug effects*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008738:Methyl Ethers / Q000494:pharmacology*; D011930:Reaction Time / Q000187:drug effects; D000077149:Sevoflurane; D014851:Wakefulness
chemical_list: D018685:Anesthetics, Inhalation; D008738:Methyl Ethers; D000077149:Sevoflurane