HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Permissions Request Permissions Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (16) Citing Articles via Google Scholar Google Scholar Articles by Díaz, O. Articles by Lisboa, C. Search for Related Content PubMed PubMed Citation Articles by Díaz, O. Articles by Lisboa, C.

Breathing pattern and gas exchange at peak exercise in COPD patients with and without tidal flow limitation at rest

¹ Dept of Respiratory Diseases, Pontificia Universidad Católica de Chile, Santiago, Chile. ² Meakins-Christie Laboratories, McGill University, Montreal, Quebec, Canada

CORRESPONDENCE: O. Díaz, Dept of Respiratory Diseases, Pontificia Universidad Católica de Chile, Marcoleta 345, 4° Piso, Santiago, Chile. Fax: 56 26335255

Keywords: arterial blood gases, breathing pattern, dynamic pulmonary hyperinflation, lung function, negative expiratory pressure method

Received: June 26, 2000
Accepted January 16, 2001

This study was supported by Grant 198/0937 from Fondecyt.

Expiratory flow limitation (FL) at rest is frequently present in chronic obstructive pulmonary disease (COPD) patients. It promotes dynamic hyperinflation with a consequent decrease in inspiratory capacity (IC). Since in COPD resting IC is strongly correlated with exercise tolerance, this study hypothesized that this is due to limitation of the maximal tidal volume (V_T,max) during exercise by the reduced IC. The present study investigated the role of tidal FL at rest on: 1) the relationship of resting IC to V_T,max; and 2) on gas exchange during peak exercise in COPD patients.

Fifty-two stable COPD patients were studied at rest, using the negative expiratory pressure technique to assess the presence of FL, and during incremental symptom-limited cycling exercise to evaluate exercise performance.

At rest, FL was present in 29 patients. In the 52 patients, a close relationship of V_T,max to IC was found using non-normalized values (r=0.77; p<0.0001), and stepwise regression analysis selected IC as the only significant predictor of V_T,max. Subgroup analysis showed that this was also the case for patients both with and without FL (r=0.70 and 0.76, respectively). In addition, in FL patients there was an increase (p<0.002) in arterial carbon dioxide partial pressure at peak exercise, mainly due to a relatively low V_T,max and consequent increase in the physiological dead space (V_D)/V_T ratio. The arterial oxygen partial pressure also decreased at peak exercise in the FL patients (p<0.05).

In conclusion, in chronic obstructive pulmonary disease patients the maximal tidal volume, and hence maximal oxygen consumption, are closely related to the reduced inspiratory capacity. The flow limited patients also exhibit a significant increase in arterial carbon dioxide partial pressure and a decrease in arterial oxygen partial pressure during peak exercise.

This article has been cited by other articles:

				P. Palange, S. A. Ward, K-H. Carlsen, R. Casaburi, C. G. Gallagher, R. Gosselink, D. E. O'Donnell, L. Puente-Maestu, A. M. Schols, S. Singh, et al. Recommendations on the use of exercise testing in clinical practice Eur. Respir. J., January 1, 2007; 29(1): 185 - 209. [Abstract] [Full Text] [PDF]

				P. M. A. Calverley Exercise and dyspnoea in COPD Eur. Respir. Rev., December 1, 2006; 15(100): 72 - 79. [Abstract] [Full Text] [PDF]

				P. M. A. Calverley Dynamic Hyperinflation: Is It Worth Measuring? Proceedings of the ATS, May 1, 2006; 3(3): 239 - 244. [Abstract] [Full Text] [PDF]

				L. Puente-Maestu, J. Garcia de Pedro, Y. Martinez-Abad, J. M. Ruiz de Ona, D. Llorente, and J. M. Cubillo Dyspnea, Ventilatory Pattern, and Changes in Dynamic Hyperinflation Related to the Intensity of Constant Work Rate Exercise in COPD Chest, August 1, 2005; 128(2): 651 - 656. [Abstract] [Full Text] [PDF]

				P. M. A. Calverley and N. G. Koulouris Flow limitation and dynamic hyperinflation: key concepts in modern respiratory physiology Eur. Respir. J., January 1, 2005; 25(1): 186 - 199. [Abstract] [Full Text] [PDF]

				E.N. Kosmas, J. Milic-Emili, A. Polychronaki, I. Dimitroulis, S. Retsou, M. Gaga, A. Koutsoukou, Ch. Roussos, and N.G. Koulouris Exercise-induced flow limitation, dynamic hyperinflation and exercise capacity in patients with bronchial asthma Eur. Respir. J., September 1, 2004; 24(3): 378 - 384. [Abstract] [Full Text] [PDF]

				I. Vogiatzis, S. Nanas, E. Kastanakis, O. Georgiadou, O. Papazahou, and Ch. Roussos Dynamic hyperinflation and tolerance to interval exercise in patients with advanced COPD Eur. Respir. J., September 1, 2004; 24(3): 385 - 390. [Abstract] [Full Text] [PDF]

				D.E. O'Donnell, N. Voduc, M. Fitzpatrick, and K.A. Webb Effect of salmeterol on the ventilatory response to exercise in chronic obstructive pulmonary disease Eur. Respir. J., July 1, 2004; 24(1): 86 - 94. [Abstract] [Full Text] [PDF]

				A. Baydur, L. Wilkinson, R. Mehdian, B. Bains, and J. Milic-Emili Extrathoracic Expiratory Flow Limitation in Obesity and Obstructive and Restrictive Disorders: Effects of Increasing Negative Expiratory Pressure Chest, January 1, 2004; 125(1): 98 - 105. [Abstract] [Full Text] [PDF]

				N.G. Koulouris, S. Retsou, E. Kosmas, K. Dimakou, K. Malagari, G. Mantzikopoulos, A. Koutsoukou, J. Milic-Emili, and J. Jordanoglou Tidal expiratory flow limitation, dyspnoea and exercise capacity in patients with bilateral bronchiectasis Eur. Respir. J., May 1, 2003; 21(5): 743 - 748. [Abstract] [Full Text] [PDF]