title: [Effect of sevoflurane on respiratory impedance measured by the forced oscillation method with random noise input].
abstract: This study was performed to investigate the effect of sevoflurane, a new inhalation anesthetic, on the respiratory impedance measured by forced oscillation method with random noise input. Random noise (1 to approximately 25Hz) oscillated by a loudspeaker was imposed on the respiratory system of dogs through a tracheostomy and the oscillatory pressure wave and flow wave were monitored at the same point with a pressure transducer and a pneumotachograph. This procedure was repeated during inhalation of 100%-oxygen, 2.0%-then 4.0%-sevoflurane-oxygen mixture, respectively. Impedance was calculated with fast Fourier transform by spectrum analyzer and a personal computer. During inhalation of 4.0%-sevoflurane-oxygen mixture, respiratory impedance especially respiratory resistance decreased at the high frequency area (6to approximately 20Hz), but 2.0%-sevoflurane-oxygen mixture did not cause a significant change of respiratory impedance. This study suggests that inhalation of an anesthetic concentration of sevoflurane produces weak bronchodilation compared with halothane or enflurane.
authors.forename: S
authors.initials: S
authors.lastname: Yasuda
authors.forename: H
authors.initials: H
authors.lastname: Sumi
authors.forename: J
authors.initials: J
authors.lastname: Masuda
authors.forename: H
authors.initials: H
authors.lastname: Sekiguchi
authors.forename: M
authors.initials: M
authors.lastname: Nagano
authors.forename: H
authors.initials: H
authors.lastname: Morishige
authors.forename: H
authors.initials: H
authors.lastname: Minamitani
mesh_terms: D000777:Anesthetics / Q000494:pharmacology*; D000818:Animals; D001696:Biomechanical Phenomena; D004285:Dogs; D004987:Ethers / Q000494:pharmacology*; D008738:Methyl Ethers; D010992:Plethysmography, Impedance; D012143:Respiratory Physiological Phenomena; D012137:Respiratory System / Q000187:drug effects*; D000077149:Sevoflurane
chemical_list: D000777:Anesthetics; D004987:Ethers; D008738:Methyl Ethers; D000077149:Sevoflurane