title: Phasic genioglossus and palatoglossus muscle activity during recovery from sevoflurane anesthesia: a prospective observational study in children.
abstract: BACKGROUND
  Inhalational anesthetic effects on upper airway muscle activity in children are largely unknown. The authors tested the hypothesis that phasic inspiratory genioglossus and palatoglossus activity increases during recovery from sevoflurane anesthesia in a dose-dependent manner in children.
  
  
  METHODS
  Sixteen children, aged 2.0 to 6.9 yr, scheduled for elective urological surgery were studied. Electromyogram recordings were acquired using intramuscular needle electrodes during spontaneous ventilation. After a 15-min period of equilibration, electromyogram activity was recorded over 30 s at each of three end-tidal concentrations, 1.5, 1.0, and 0.5 minimum alveolar concentration (MAC), administered in sequence.
  
  
  RESULTS
  Phasic genioglossus activity was noted in four children at 1.5 MAC, five at 1.0 MAC, and six children at 0.5 MAC sevoflurane. Phasic palatoglossus activity was noted in 4 children at 1.5 MAC, 6 at 1.0 MAC, and 10 children at 0.5 MAC sevoflurane. Both the proportion of children exhibiting phasic activity, and the magnitude of phasic activity increased during recovery from anesthesia. For the genioglossus, decreasing the depth of sevoflurane anesthesia from 1.5 to 1.0 MAC increased phasic activity by approximately 35% and a further decrease to 0.5 MAC more than doubled activity (median [range] at 1.5 and 0.5 MAC: 2.7 μV [0 to 4.0 μV] and 8.6 μV [3.2 to 17.6], respectively; P = 0.029). A similar dose-related increase was recorded at the palatoglossus (P = 0.0002).
  
  
  CONCLUSIONS
  Genioglossus and palatoglossus activity increases during recovery from sevoflurane anesthesia in a dose-dependent manner over the clinical range of sevoflurane concentrations in children.
authors.affiliation: Department of Anesthesia and Pain Medicine, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Ilavajady
authors.initials: I
authors.lastname: Srinivasan
authors.forename: Samuel
authors.initials: S
authors.lastname: Strantzas
authors.forename: Mark W
authors.initials: MW
authors.lastname: Crawford
mesh_terms: D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D002648:Child; D002675:Child, Preschool; D004305:Dose-Response Relationship, Drug; D004576:Electromyography; D006801:Humans; D008738:Methyl Ethers / Q000494:pharmacology*; D010156:Palatal Muscles / Q000187:drug effects* / Q000502:physiology; D010609:Pharyngeal Muscles / Q000187:drug effects* / Q000502:physiology; D011446:Prospective Studies; D000077149:Sevoflurane
chemical_list: D018685:Anesthetics, Inhalation; D008738:Methyl Ethers; D000077149:Sevoflurane