title: Respiratory mechanics measured by forced oscillation technique in combined pulmonary fibrosis and emphysema.
abstract: The coexistence of emphysema and pulmonary fibrosis is known as combined pulmonary fibrosis and emphysema (CPFE). The aim of this study was to compare the lung mechanics measured by multi-frequency forced oscillation technique (FOT) among patients with CPFE, interstitial pneumonia (IP), and chronic obstructive pulmonary disease (COPD). FOT and pulmonary function tests were performed in 41 patients with CPFE, 47 with IP, and 86 with COPD. Whole-breath resistance at 20 Hz was significantly lower in patients with CPFE than in those with IP or COPD, irrespective of the severity of airflow limitation. Within-breath analyses of resistance revealed no difference among the 3 groups; however, the difference between inspiratory and expiratory phases of reactance at 5 Hz, which reflects expiratory flow limitation, in patients with CPFE was significantly higher than in those with IP and lower than in those with COPD. In conclusion, both emphysema and fibrosis affect lung mechanics in CPFE, leading to different findings from IP or COPD alone.
authors.affiliation: Department of Respiratory Medicine, Shizuoka General Hospital, Shizuoka, Japan. mori-kazutaka@tokai.or.jp
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Mori
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Shirai
authors.forename: Masashi
authors.initials: M
authors.lastname: Mikamo
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Shishido
authors.forename: Takefumi
authors.initials: T
authors.lastname: Akita
authors.forename: Satoru
authors.initials: S
authors.lastname: Morita
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Asada
authors.forename: Masato
authors.initials: M
authors.lastname: Fujii
authors.forename: Hironao
authors.initials: H
authors.lastname: Hozumi
authors.forename: Takafumi
authors.initials: T
authors.lastname: Suda
authors.forename: Kingo
authors.initials: K
authors.lastname: Chida
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000403:Airway Resistance; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009991:Oscillometry; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology*; D011656:Pulmonary Emphysema / Q000175:diagnosis / Q000503:physiopathology*; D011658:Pulmonary Fibrosis / Q000503:physiopathology*; D012129:Respiratory Function Tests / Q000379:methods; D012189:Retrospective Studies; D012720:Severity of Illness Index