HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS REGISTER		Author Keyword(s) Vol Page [Advanced]

This Article Full Text Full Text (PDF) Web-only appendices All Versions of this Article: thx.2005.053470v1 thx.2005.053470v2 61/7/559    most recent Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this link to a friend Similar articles in this journal Similar articles in PubMed Add article to my folders Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Peters, M M Articles by O’Donnell, D E Search for Related Content PubMed PubMed Citation Articles by Peters, M M Articles by O’Donnell, D E Topic Collections Relevant Article

Combined physiological effects of bronchodilators and hyperoxia on exertional dyspnoea in normoxic COPD

Respiratory Investigation Unit, Department of Medicine, Queen’s University, Kingston, Ontario, Canada

Correspondence to:
Correspondence to:
Dr D E O’Donnell
102 Stuart Street, Kingston, Ontario K7L 2V6, Canada; odonnell{at}post.queensu.ca

Background: Studies examining the physiological interactions of oxygen (O₂) and bronchodilators (BD) during exercise in chronic obstructive pulmonary disease (COPD) should provide new insights into mechanisms of exercise intolerance. We examined the effects of O₂ and BD, alone and in combination, on dyspnoea, ventilation (E), breathing pattern, operating lung volumes, and exercise endurance.

Methods: In a randomised, double blind, crossover study, 16 patients with COPD (mean (SE) FEV₁ 43(3)% predicted) performed pulmonary function tests and an incremental exercise test, then completed four visits in which they received either nebulised BD (ipratropium 0.5 mg + salbutamol 2.5 mg) or placebo (PL) with either 50% O₂ or room air (RA). After 90–105 minutes the patients performed pulmonary function tests, then breathed RA or O₂ during symptom limited constant load exercise at 75% peak work rate.

Results: With BD the mean (SE) increase in inspiratory capacity (IC) was 0.3 (0.1) l (p<0.05) at rest and during exercise, permitting greater tidal volume (VT) expansion during exercise and a greater peak E. With O₂, E decreased during exercise as a result of decreased breathing frequency (F), with no significant change in IC. During exercise with BD+O₂, IC and VT increased, F decreased, and E did not change. Dyspnoea decreased with all interventions at a standardised time during exercise compared with PL+RA (p<0.05). Endurance time was significantly (p<0.05) greater with BD+O₂ (10.4 (1.6) min) than with O₂ (8.5 (1.4) min), BD (7.1 (1.3) min) and PL+RA (5.4 (0.9) min).

Conclusion: By combining the benefits of BD (reduced hyperinflation) and O₂ (reduced ventilatory drive), additive effects on exercise endurance were observed in patients with normoxic COPD.

Abbreviations: BD, bronchodilator; COPD, chronic obstructive pulmonary disease; EELV, end expiratory lung volume; EILV, end inspiratory lung volume; F, breathing frequency; FEV₁, forced expired volume in 1 second; FRC, functional residual capacity; FVC, forced vital capacity; IC, inspiratory capacity; IRV, inspiratory reserve volume; O₂, oxygen; PaCO₂, arterial carbon dioxide tension; PImax, maximal inspiratory pressure; PEFR, peak expiratory flow rate; PL, placebo; RA, room air; RV, residual volume; SaO₂, oxygen saturation; TI, TE, inspiratory and expiratory time; TLC, total lung capacity; TLCO, lung carbon monoxide transfer factor; CO₂, carbon dioxide output; E, minute ventilation; O₂, oxygen consumption; VT, total volume

Keywords: chronic obstructive pulmonary disease; bronchodilators; oxygen; exercise; dyspnoea; lung hyperinflation

Relevant Article

Airwaves

Wisia Wedzicha
Thorax 2006 61: 551. [Extract] [Full Text] [PDF]

This article has been cited by other articles:

				A Borghi-Silva, C C Oliveira, C Carrascosa, J Maia, D C Berton, F Queiroga Jr, E M Ferreira, D R Almeida, L E Nery, and J A Neder Respiratory muscle unloading improves leg muscle oxygenation during exercise in patients with COPD Thorax, October 1, 2008; 63(10): 910 - 915. [Abstract] [Full Text] [PDF]

				D. E. O'Donnell and K. A. Webb The major limitation to exercise performance in COPD is dynamic hyperinflation J Appl Physiol, August 1, 2008; 105(2): 753 - 755. [Full Text] [PDF]

				J. B. West, P. D. Wagner, J. A. Neder, G. L. Scano, N. L. Jones, S. G. Zakynthinos, I. Vogiatzis, L. Nici, P. M. Calverley, H. R. Gosker, et al. The major limitation to exercise performance in COPD is inadequate energy supply to the respiratory and locomotor muscles vs. lower limb muscle dysfunction vs. dynamic hyperinflation J Appl Physiol, August 1, 2008; 105(2): 758 - 762. [Full Text] [PDF]

				D Jensen, K Amjadi, V Harris-McAllister, K A Webb, and D E O'Donnell Mechanisms of dyspnoea relief and improved exercise endurance after furosemide inhalation in COPD Thorax, July 1, 2008; 63(7): 606 - 613. [Abstract] [Full Text] [PDF]

				P. Albert and P. M. A. Calverley Drugs (including oxygen) in severe COPD Eur. Respir. J., May 1, 2008; 31(5): 1114 - 1124. [Abstract] [Full Text] [PDF]

				P. Calverley Understanding Breathlessness in Mild Chronic Obstructive Pulmonary Disease Am. J. Respir. Crit. Care Med., March 15, 2008; 177(6): 564 - 565. [Full Text] [PDF]

				D. Ofir, P. Laveneziana, K. A. Webb, and D. E. O'Donnell Ventilatory and perceptual responses to cycle exercise in obese women J Appl Physiol, June 1, 2007; 102(6): 2217 - 2226. [Abstract] [Full Text] [PDF]

				D. D. Marciniuk, S. J. Butcher, J. K. Reid, G. F. MacDonald, N. D. Eves, R. Clemens, and R. L. Jones The Effects of Helium-Hyperoxia on 6-min Walking Distance in COPD: A Randomized, Controlled Trial Chest, June 1, 2007; 131(6): 1659 - 1665. [Abstract] [Full Text] [PDF]

				D. E. O'Donnell, R. B. Banzett, V. Carrieri-Kohlman, R. Casaburi, P. W. Davenport, S. C. Gandevia, A. F. Gelb, D. A. Mahler, and K. A. Webb Pathophysiology of Dyspnea in Chronic Obstructive Pulmonary Disease: A Roundtable Proceedings of the ATS, May 1, 2007; 4(2): 145 - 168. [Abstract] [Full Text] [PDF]

				E. F. M. Wouters Nonpharmacological modulation of dynamic hyperinflation Eur. Respir. Rev., December 1, 2006; 15(100): 90 - 96. [Abstract] [Full Text] [PDF]

				D. E. O'Donnell, A. L. Hamilton, and K. A. Webb Sensory-mechanical relationships during high-intensity, constant-work-rate exercise in COPD J Appl Physiol, October 1, 2006; 101(4): 1025 - 1035. [Abstract] [Full Text] [PDF]

				R Casaburi Combination therapy for exercise intolerance in COPD. Thorax, July 1, 2006; 61(7): 551 - 552. [Full Text] [PDF]