title: Electroencephalogram reactivity to verbal command after dexmedetomidine, propofol and sevoflurane-induced unresponsiveness.
abstract: Although electroencephalogram reactivity (i.e. transient changes in electrical brain activity following external stimulus) might be useful in depth-of-anaesthesia monitoring, it has not been systematically examined with different anaesthetics at doses titrated to unresponsiveness. Three 10-subject groups of healthy volunteers received dexmedetomidine, propofol or sevoflurane in escalating pseudo-steady-state concentrations at 10-min intervals until they did not open their eyes to command. The electroencephalogram was continuously recorded and spectral variables were calculated with short-time Fourier transform and time-varying autoregressive modelling. Electroencephalogram reactivity was most prominent in the midfrontal derivations (termed F3 and F4). During drug-induced unresponsiveness, electroencephalogram reactivity was still present in all drug groups. Dexmedetomidine, propofol and sevoflurane induced distinct suppression patterns on the electroencephalogram reactivity at the same clinical endpoint (unresponsiveness). Reactivity was best maintained with propofol, while only minimally preserved with dexmedetomidine and sevoflurane. Thus, it may be difficult to harness reactivity for depth-of-anaesthesia monitoring.
authors.affiliation: Department of Perioperative Services, Intensive Care and Pain Medicine, Turku University Hospital, Turku, Finland.
authors.forename: K
authors.initials: K
authors.lastname: Kaskinoro
authors.forename: A
authors.initials: A
authors.lastname: Maksimow
authors.forename: S
authors.initials: S
authors.lastname: Georgiadis
authors.forename: J
authors.initials: J
authors.lastname: Långsjö
authors.forename: H
authors.initials: H
authors.lastname: Scheinin
authors.forename: P
authors.initials: P
authors.lastname: Karjalainen
authors.forename: S K
authors.initials: SK
authors.lastname: Jääskeläinen
mesh_terms: D000328:Adult; D000762:Anesthesia Recovery Period; D018685:Anesthetics, Inhalation / Q000494:pharmacology; D018686:Anesthetics, Intravenous / Q000494:pharmacology; D054810:Deep Sedation / Q000379:methods*; D020927:Dexmedetomidine / Q000494:pharmacology*; D004569:Electroencephalography / Q000187:drug effects*; D005583:Fourier Analysis; D006801:Humans; D006993:Hypnotics and Sedatives / Q000494:pharmacology; D008297:Male; D008738:Methyl Ethers / Q000494:pharmacology*; D015742:Propofol / Q000494:pharmacology*; D000077149:Sevoflurane; D014705:Verbal Behavior / Q000187:drug effects*; D055815:Young Adult
chemical_list: D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D006993:Hypnotics and Sedatives; D008738:Methyl Ethers; D000077149:Sevoflurane; D020927:Dexmedetomidine; D015742:Propofol