title: The site of airway irritation during induction of anaesthesia.
abstract: The aim of this investigation was to study the role of the nasal airway in mediating upper airway reflexes during induction of anaesthesia when the commonly used irritant inhalational anaesthetic agent enflurane is used. In a prospective randomised study, 40 ASA 1 & 2 day-case patients undergoing body surface surgery were recruited. Following intravenous induction using propofol, 20 patients received enflurane administered via a laryngeal mask airway (LMA), the anaesthetic vapour therefore bypassing the nasal airway. In the other group, 20 patients received enflurane anaesthesia administered using a face mask, the nasal airway therefore being exposed to inhalation anaesthetic. We were unable to demonstrate any significant (p < 0.05) differences between the two groups in relation to upper airway complications (cough, breath holding, laryngeal spasm, bronchospasm and excitement). Previous work has identified the nose as a possible important reflexogenic site for upper airway reflexes in humans during anaesthesia. We have been unable to demonstrate any difference in upper airway complications when the nasal airway was included or excluded from exposure to irritant anaesthetic vapours, when administered in a clinical setting.
authors.affiliation: Department of Anaesthesia, Derriford Hospital, Plymouth, UK.
authors.forename: A K
authors.initials: AK
authors.lastname: Dashfield
authors.forename: S E
authors.initials: SE
authors.lastname: Bree
authors.forename: A M
authors.initials: AM
authors.lastname: Weiss
authors.forename: J A
authors.initials: JA
authors.lastname: Langton
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D018685:Anesthetics, Inhalation / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D004737:Enflurane / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D005260:Female; D006801:Humans; D017214:Laryngeal Masks; D008297:Male; D008397:Masks; D008875:Middle Aged; D009297:Nasal Mucosa / Q000187:drug effects* / Q000503:physiopathology; D011446:Prospective Studies; D012018:Reflex / Q000187:drug effects*; D012120:Respiration Disorders / Q000139:chemically induced* / Q000503:physiopathology
chemical_list: D018685:Anesthetics, Inhalation; D004737:Enflurane