title: [Partitioning and measurement of respiratory impedance into central and peripheral airways with catheter tip type transducer].
abstract: In this study, we have examined the availability of catheter tip type transducer for the partitioning of respiratory impedance. Total respiratory resistance and reactance from 1 to 20 Hz determined by forced oscillation method with random noise input in anesthetized dogs were partitioned by catheter tip type transducer into central airway resistance (Rc) and reactance (Xc) as well as peripheral resistance (Rp) and reactance (Xp). Intratracheal acetylcholine (0.1g) increased Rp at the wide frequency range (from about 1 to 20 Hz), although Rc did not change with it. The decreases of Rc at higher frequencies (over 12Hz) were produced by intratracheal salbutamol (10mg), whereas Rp did not change significantly. These results suggest that the predominant site of action of intratracheal acetylcholine and salbutamol is peripheral airway and central airway respectively. We have concluded that the respiratory impedance can be partitioned noninvasively with catheter tip type transducer without pneumothorax and hemorrhage caused with the retrograde catheter. This method can be applied clinically during general anesthesia or in intensive care.
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: D000109:Acetylcholine / Q000494:pharmacology; D000403:Airway Resistance / Q000187:drug effects; D000420:Albuterol / Q000494:pharmacology; D000818:Animals; D001980:Bronchi / Q000187:drug effects / Q000502:physiology*; D002408:Catheters, Indwelling; D004285:Dogs; D004867:Equipment Design; D014160:Transducers, Pressure
chemical_list: D000109:Acetylcholine; D000420:Albuterol