title: Dynamic hyperinflation and dyspnea during the 6-minute walk test in stable chronic obstructive pulmonary disease patients.
abstract: The purpose of this study was to investigate the relationship between dynamic hyperinflation and dyspnea and to clarify the characteristics of dyspnea during the 6-minute walk test (6MWT) in chronic obstructive pulmonary disease patients. Twenty-three subjects with stable moderate chronic obstructive pulmonary disease (age 73.8±5.8 years, all male) took part in this study. During the 6MWT, ventilatory and gas exchange parameters were measured using a portable respiratory gas analysis system. Dyspnea and oxygen saturation were recorded at the end of every 2 minute period during the test. There was a significant decrease in inspiratory capacity during the 6MWT. This suggested that dynamic hyperinflation had occurred. Dyspnea showed a significant linear increase, and there was a significant negative correlation with inspiratory capacity. It was suggested that one of the reasons that dyspnea developed during the 6MWT was the dynamic hyperinflation. Even though the tidal volume increased little after 2 minutes, dyspnea increased linearly to the end of the 6MWT. These results suggest that the mechanisms generating dyspnea during the 6MWT were the sense of respiratory effort at an early stage and then the mismatch between central motor command output and respiratory system movement.
authors: Department of Physical Therapy, Akita University Graduate School of Health Sciences, Akita, Japan.
authors: Masahiro
authors: M
authors: Satake
authors: Department of Physical Therapy, Akita University Graduate School of Health Sciences, Akita, Japan.
authors: Takanobu
authors: T
authors: Shioya
authors: Department of Physical Therapy, Akita University Graduate School of Health Sciences, Akita, Japan.
authors: Sachiko
authors: S
authors: Uemura
authors: Department of Rehabilitation, Akita City Hospital, Akita, Japan.
authors: Hitomi
authors: H
authors: Takahashi
authors: Department of Rehabilitation, Akita City Hospital, Akita, Japan.
authors: Keiyu
authors: K
authors: Sugawara
authors: Department of Rehabilitation, Akita City Hospital, Akita, Japan.
authors: Chikage
authors: C
authors: Kasai
authors: Department of Rehabilitation, Akita City Hospital, Akita, Japan.
authors: Noritaka
authors: N
authors: Kiyokawa
authors: Department of Rehabilitation, Akita City Hospital, Akita, Japan.
authors: Toru
authors: T
authors: Watanabe
authors: Department of Rehabilitation, Akita City Hospital, Akita, Japan.
authors: Sayaka
authors: S
authors: Sato
authors: Department of Rehabilitation, Akita City Hospital, Akita, Japan.
authors: Atsuyoshi
authors: A
authors: Kawagoshi
mesh_terms: D000368:Aged; D004417:Dyspnea / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D005080:Exercise Test / Q000379:methods*; D017079:Exercise Tolerance; D006801:Humans; D016014:Linear Models; D008168:Lung / Q000294:innervation / Q000503:physiopathology*; D008297:Male; D009046:Motor Neurons; D011237:Predictive Value of Tests; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D011659:Pulmonary Gas Exchange; D012123:Pulmonary Ventilation; D012125:Respiratory Center / Q000503:physiopathology; D012720:Severity of Illness Index; D013997:Time Factors; D016138:Walking
keywords: Borg CR-10 scale; COPD; IC; IRV; chronic respiratory diseases; field walking test; inspiratory capacity; inspiratory reserve volume; respiratory gas analysis
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