title: The correlation of the Narcotrend Index with endtidal sevoflurane concentrations and hemodynamic parameters in children.
abstract: BACKGROUND
  The Narcotrend Index (NI) of anesthetic depth is potentially a pharmacodynamic measure of the effects of sevoflurane on the brain.
  
  
  METHODS
  In this prospective observational study of 30 pediatric surgical patients (1-11 years), we investigated the correlation between nonsteady-state endtidal sevoflurane (eT(Sevo)), NI, mean arterial pressure (MAP), and heart rate (HR). The performance of the Narcotrend for differentiation between consciousness and unconsciousness was evaluated using prediction probability (P(K)).
  
  
  RESULTS
  Spearman correlation analysis showed significant correlations (P < 0.01) between eT(Sevo) and NI (r = -0.85) and MAP (r = -0.43). P(K)-values for differentiation between consciousness and unconsciousness were 1.0 for NI and <0.85 for MAP and HR. During the surgical procedure, NI-values showed a constant rise with each 0.5% step of lowering eT(Sevo) (P < 0.03), whereas MAP remained unaltered and HR showed a constant decline (P < 0.03), except between 1.5 and 1%.
  
  
  CONCLUSIONS
  In children, nonsteady-state eT(Sevo) concentrations are more closely related with NI than with MAP or HR. In this study, only NI reliably differentiated consciousness from unconsciousness.
authors.affiliation: Department of Anaesthesia, University of Regensburg, Regensburg, Germany. frank.weber@klinik.uni-regensburg.de
authors.forename: Frank
authors.initials: F
authors.lastname: Weber
authors.forename: Harald
authors.initials: H
authors.lastname: Hollnberger
authors.forename: Michael
authors.initials: M
authors.lastname: Gruber
authors.forename: Bernhard
authors.initials: B
authors.lastname: Frank
authors.forename: Kai
authors.initials: K
authors.lastname: Taeger
mesh_terms: D000769:Anesthesia, Inhalation; D018685:Anesthetics, Inhalation / Q000493:pharmacokinetics*; D001794:Blood Pressure / Q000187:drug effects; D002675:Child, Preschool; D004569:Electroencephalography / Q000187:drug effects*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D007223:Infant; D008297:Male; D008738:Methyl Ethers / Q000493:pharmacokinetics*; D016343:Monitoring, Intraoperative; D011446:Prospective Studies; D000077149:Sevoflurane
chemical_list: D018685:Anesthetics, Inhalation; D008738:Methyl Ethers; D000077149:Sevoflurane