title: Airway protective reflexes evoked by laryngeal instillation of distilled water under sevoflurane general anesthesia in children.
abstract: To investigate how sevoflurane modifies airway protective reflexes in anesthetized children, we recruited patients younger than 12-yr-old for our study. Anesthesia was induced with inhaled sevoflurane in oxygen. The airway was managed with a laryngeal mask airway and the patient breathing spontaneously. Depending on the depth of anesthesia, the subjects were divided into two groups: Group 1 and Group 2 (1% and 2% of end-tidal sevoflurane concentration, respectively). Behaviors of the larynx were assessed mainly by the fiberscopic images of the larynx as well as respiratory flow and esophageal pressure. A small dose, 0.02 mL/kg of distilled water (minimum 0.2 mL) was instilled to the larynx through a channel of the scope to evoke an airway protective reflex from the larynx. The responses were categorized into passive (laryngeal closure, laryngospasm, and apnea) and active (cough, expiration reflex, and swallowing reflex) responses. Ten subjects were included in each group. In both groups, the primary responses were passive; however, in Group 1, active reflexes were also observed in 8 of 10 subjects; no subjects in Group 2 had active reflexes (P < 0.01). We concluded that, in children, the depth of general anesthesia with sevoflurane modified airway protective reflexes.
authors.affiliation: Department of Anesthesiology (B1), Chiba University Graduate School of Medicine, Tokyo, Japan.
authors.forename: Teruhiko
authors.initials: T
authors.lastname: Ishikawa
authors.forename: Shiroh
authors.initials: S
authors.lastname: Isono
authors.forename: Atsuko
authors.initials: A
authors.lastname: Tanaka
authors.forename: Yugo
authors.initials: Y
authors.lastname: Tagaito
authors.forename: Takashi
authors.initials: T
authors.lastname: Nishino
mesh_terms: D000768:Anesthesia, General; D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D017214:Laryngeal Masks; D007830:Larynx / Q000502:physiology*; D008738:Methyl Ethers / Q000494:pharmacology*; D012018:Reflex / Q000187:drug effects*; D000077149:Sevoflurane; D014867:Water
chemical_list: D018685:Anesthetics, Inhalation; D008738:Methyl Ethers; D014867:Water; D000077149:Sevoflurane