title: Association of the forced oscillation technique with negative expiratory pressure in COPD.
abstract: Expiratory flow limitation (EFL) during tidal breathing is common in patients with severe COPD, and a major determinant of dynamic hyperinflation and exercise limitation. The negative expiratory pressure (NEP) technique has been the gold standard to detect EFL, while the forced oscillation technique (FOT) has also been reported to detect it. However, the association of FOT with NEP is not fully understood. We assessed whether broadband frequency FOT would predict the presence of EFL measured by NEP. FOT, NEP, and spirometry were performed in 51 patients with COPD. The extent of emphysema was measured by high-resolution computed tomography and scored. Fifteen patients were classified into the EFL-positive group and 36 into the EFL-negative group. In multivariate logistic regression analysis, EFL was independently predicted by emphysema score, forced vital capacity, and whole-breath respiratory system reactance at 5Hz (X5). The receiver operator characteristic curve analysis revealed that inspiratory X5 best predicted EFL-positivity. X5-related forced oscillatory parameters are useful for detecting EFL in the management of COPD.
authors.affiliation: Department of Respiratory Medicine, Shizuoka General Hospital, Shizuoka, Japan. Electronic address: takefumi-akita@i.shizuoka-pho.jp.
authors.forename: Takefumi
authors.initials: T
authors.lastname: Akita
authors.affiliation: Department of Respiratory Medicine, Shizuoka General Hospital, Shizuoka, Japan. Electronic address: toshihiro-shirai@i.shizuoka-pho.jp.
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Shirai
authors.affiliation: Second Department of Internal Medicine, Hamamatsu University School of Medicine, Hamamatsu, Japan. Electronic address: mori.kazutaka@gmail.com.
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Mori
authors.affiliation: Department of Respiratory Medicine, Shizuoka General Hospital, Shizuoka, Japan. Electronic address: sffyb295@yahoo.co.jp.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Shimoda
authors.affiliation: Department of Respiratory Medicine, Shizuoka General Hospital, Shizuoka, Japan. Electronic address: takahito-suzuki@i.shizuoka-pho.jp.
authors.forename: Takahito
authors.initials: T
authors.lastname: Suzuki
authors.affiliation: Department of Respiratory Medicine, Shizuoka General Hospital, Shizuoka, Japan. Electronic address: ichirohaya1223@gmail.com.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Hayashi
authors.affiliation: Department of Respiratory Medicine, Shizuoka General Hospital, Shizuoka, Japan. Electronic address: rienk0117@gmail.com.
authors.forename: Rie
authors.initials: R
authors.lastname: Noguchi
authors.affiliation: Department of Respiratory Medicine, Shizuoka General Hospital, Shizuoka, Japan. Electronic address: eisukefukui@gmail.com.
authors.forename: Eisuke
authors.initials: E
authors.lastname: Mochizuki
authors.affiliation: Department of Respiratory Medicine, Shizuoka General Hospital, Shizuoka, Japan. Electronic address: sakshow@hotmail.com.
authors.forename: Shogo
authors.initials: S
authors.lastname: Sakurai
authors.affiliation: Department of Respiratory Medicine, Shizuoka General Hospital, Shizuoka, Japan. Electronic address: mika-saigusa@i.shizuoka-pho.jp.
authors.forename: Mika
authors.initials: M
authors.lastname: Saigusa
authors.affiliation: Department of Respiratory Medicine, Shizuoka General Hospital, Shizuoka, Japan. Electronic address: taisuke-akamatsu@i.shizuoka-pho.jp.
authors.forename: Taisuke
authors.initials: T
authors.lastname: Akamatsu
authors.affiliation: Department of Respiratory Medicine, Shizuoka General Hospital, Shizuoka, Japan. Electronic address: akito_boo@hotmail.com.
authors.forename: Akito
authors.initials: A
authors.lastname: Yamamoto
authors.affiliation: Department of Respiratory Medicine, Shizuoka General Hospital, Shizuoka, Japan. Electronic address: sisidiba@gmail.com.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Shishido
authors.affiliation: Department of Respiratory Medicine, Shizuoka General Hospital, Shizuoka, Japan. Electronic address: cqn00563@nifty.com.
authors.forename: Satoru
authors.initials: S
authors.lastname: Morita
authors.affiliation: Department of Respiratory Medicine, Shizuoka General Hospital, Shizuoka, Japan. Electronic address: kazuhiro-asada@i.shizuoka-pho.jp.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Asada
authors.affiliation: Second Department of Internal Medicine, Hamamatsu University School of Medicine, Hamamatsu, Japan. Electronic address: suda@hama-med.ac.jp.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Suda
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D004646:Emphysema / Q000503:physiopathology; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000503:physiopathology*; D012372:ROC Curve; D012680:Sensitivity and Specificity; D013147:Spirometry; D014057:Tomography, X-Ray Computed
keywords: Expiratory flow limitation; Forced oscillation technique; Negative expiratory pressure; Reactance; Tidal breathing