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Thorax 2009;64:216-223 doi:10.1136/thx.2008.103598
  • Chronic obstructive pulmonary disease

Evaluation of acute bronchodilator reversibility in patients with symptoms of GOLD stage I COPD

  1. D E O’Donnell1,
  2. P Laveneziana1,
  3. J Ora1,
  4. K A Webb1,
  5. Y-M Lam2,
  6. D Ofir1
  1. 1
    Respiratory Investigation Unit, Department of Medicine, Queen’s University and Kingston General Hospital, Kingston, Ontario, Canada
  2. 2
    Department of Community Health and Epidemiology, Queen’s University, Kingston, Ontario, Canada
  1. Dr D O’Donnell, 102 Stuart Street, Kingston, Ontario, Canada K7L 2V6; odonnell{at}queensu.ca
  • Received 27 June 2008
  • Accepted 2 November 2008
  • Published Online First 3 December 2008

Abstract

Background: Patients with symptoms of GOLD stage I chronic obstructive pulmonary disease (COPD) can have significant abnormalities of ventilatory mechanics with greater exertional symptoms and exercise limitation than age-matched healthy subjects. In such patients the impact of bronchodilator therapy remains unknown and is difficult to evaluate.

Methods: The acute effects of nebulised ipratropium bromide 500 μg (IB) on resting pulmonary function and on dyspnoea and ventilatory parameters during symptom-limited constant work rate cycle exercise were measured. In a randomised double-blind crossover study, 16 patients with COPD (mean (SD) post-bronchodilator forced expiratory volume in 1 s (FEV1) 90 (7)% predicted, FEV1/forced vital capacity (FVC) 59 (7)%) with a significant smoking history (mean (SD) 44 (16) pack-years) inhaled either IB or placebo on each of two separate visits. Pulmonary function tests and cycle exercise at 80–85% of each subject’s maximal work capacity were performed 2 h after dosing.

Results: Compared with placebo, FEV1 increased 5 (9)% predicted, residual volume decreased 12 (20)% predicted and specific airway resistance decreased 81 (93)% predicted (all p<0.05) after IB. At a standardised time during exercise, dynamic inspiratory capacity and tidal volume significantly increased in tandem by 0.12 and 0.16 litres, respectively (each p<0.05), dyspnoea fell by 0.9 (1.8) Borg units (p = 0.07) and dyspnoea/ventilation ratios fell significantly (p<0.05). The fall in dyspnoea intensity at higher submaximal ventilations correlated with the concurrent decrease in end-expiratory lung volume (p<0.05).

Conclusion: In patients with symptoms of GOLD stage I COPD, IB treatment is associated with modest but consistent improvements in airway function, operating lung volumes and dyspnoea intensity during exercise. These results provide a physiological rationale for a trial of bronchodilator therapy in selected patients with milder but symptomatic COPD.

Footnotes

  • Additional Methods data are published online only at http://thorax.bmj.com/content/vol64/issue3

  • Presented in part at the ALA/ATS International Conference, Toronto, May 2008 (Ofir D, Laveneziana P, Webb KA, et al. Evaluation of bronchodilator efficacy in symptomatic patients with GOLD stage I COPD. Am J Respir Crit Care Med 2008;177(Suppl):A649).

  • Funding: Supported by William M Spear endowment fund, Queen’s University.

  • Competing interests: None.

  • Ethics approval: This study was approved by the Queen’s University and Affiliated Hospitals research ethics board.

This Article

  1. Abstract
  2. Full text
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  4. web only appendix
  5. All Versions of this Article:
    1. thx.2008.103598v1
    2. 64/3/216 most recent

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