| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS | REGISTER |
|
|
|
|
|||||||||||||
|
|
|||||||||||||||
RESPIRATORY MUSCLES |
1 Respiratory Muscle Laboratory, Guy’s, King’s and St Thomas’ School of Medicine, King’s College Hospital, London, UK
2 Royal Brompton Hospital, London, UK
3 Department of Statistics (Research & Development), King’s College Hospital, London, UK
Correspondence to:
Correspondence to:
Dr W D C Man
Respiratory Muscle Laboratory, Guy’s, King’s and St Thomas’ School of Medicine, King’s College Hospital, Bessemer Road, London SE5 9PJ, UK; william.man{at}kcl.ac.uk
Background: Some patients with irreversible chronic obstructive pulmonary disease (COPD) experience subjective benefit from long acting bronchodilators without change in forced expiratory volume in 1 second (FEV1). Dynamic hyperinflation is an important determinant of exercise induced dyspnoea in COPD. We hypothesised that long acting bronchodilators improve symptoms by reducing dynamic hyperinflation and work of breathing, as measured by respiratory muscle pressure-time products.
Methods: Sixteen patients with "irreversible" COPD (<10% improvement in FEV1 following a bronchodilator challenge; mean FEV1 31.1% predicted) were recruited into a randomised, double blind, placebo controlled, crossover study of salmeterol (50 µg twice a day). Treatment periods were of 2 weeks duration with a 2 week washout period. Primary outcome measures were end exercise isotime transdiaphragmatic pressure-time product and dynamic hyperinflation as measured by inspiratory capacity.
Results: Salmeterol significantly reduced the transdiaphragmatic pressure-time product (294.5 v 348.6 cm H2O/s/min; p = 0.03), dynamic hyperinflation (0.22 v 0.33 litres; p = 0.002), and Borg scores during endurance treadmill walk (3.78 v 4.62; p = 0.02). There was no significant change in exercise endurance time. Improvements in isotime Borg score were significantly correlated to changes in tidal volume/oesophageal pressure swings, end expiratory lung volume, and inspiratory capacity, but not pressure-time products.
Conclusions: Despite apparent "non-reversibility" in spirometric parameters, long acting bronchodilators can cause both symptomatic and physiological improvement during exercise in severe COPD.
Keywords: chronic obstructive pulmonary disease; salmeterol; pressure-time product; dynamic hyperinflation; respiratory muscles
Abbreviations: DH, dynamic hyperinflation; EELV, end expiratory lung volume; EILV, end inspiratory lung volume FEV1, forced expiratory volume in 1 second; IC, inspiratory capacity; IRV, inspiratory reserve volume; ISW, incremental shuttle walk; PaO2, PaCO2, arterial oxygen and carbon dioxide tensions; PEEPi, intrinsic positive end expiratory pressure; PImax, maximum inspiratory pressure; Pdi, diaphragmatic pressure; Pga, gastric pressure; Poes, oesophageal pressure; PTP, pressure-time product; RV, residual volume; TLCO, carbon monoxide transfer factor; TLC, total lung capacity; VC, vital capacity; VO2peak, peak oxygen consumption
This article has been cited by other articles:
|
|
 |
|
  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. G. Camp and S. M. Goring Gender and the Diagnosis, Management, and Surveillance of Chronic Obstructive Pulmonary Disease Proceedings of the ATS, December 1, 2007; 4(8): 686 - 691. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. F. Rabe, S. Hurd, A. Anzueto, P. J. Barnes, S. A. Buist, P. Calverley, Y. Fukuchi, C. Jenkins, R. Rodriguez-Roisin, C. van Weel, et al. Global Strategy for the Diagnosis, Management, and Prevention of Chronic Obstructive Pulmonary Disease: GOLD Executive Summary Am. J. Respir. Crit. Care Med., September 15, 2007; 176(6): 532 - 555. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. E. O'Donnell Impacting patient-centred outcomes in COPD: breathlessness and exercise tolerance Eur. Respir. Rev., December 1, 2006; 15(99): 37 - 41. [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]
|
|
|
|
 |
|
 D. E. O'Donnell, F. Sciurba, B. Celli, D. A. Mahler, K. A. Webb, C. J. Kalberg, and K. Knobil Effect of Fluticasone Propionate/Salmeterol on Lung Hyperinflation and Exercise Endurance in COPD. Chest, September 1, 2006; 130(3): 647 - 656. [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]
|
|
|
|
|
|
J. A. Wedzicha Heliox in chronic obstructive pulmonary disease: lightening the airflow. Am. J. Respir. Crit. Care Med., April 15, 2006; 173(8): 825 - 826. [Full Text] [PDF]
|
|
|
|
|
|
D. E. O'Donnell Hyperinflation, dyspnea, and exercise intolerance in chronic obstructive pulmonary disease. Proceedings of the ATS, January 1, 2006; 3(2): 180 - 184. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A Aliverti, K Rodger, R L Dellaca, N Stevenson, A Lo Mauro, A Pedotti, and P M A Calverley Effect of salbutamol on lung function and chest wall volumes at rest and during exercise in COPD Thorax, November 1, 2005; 60(11): 916 - 924. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W D-C Man, N S Hopkinson, F Harraf, D Nikoletou, M I Polkey, and J Moxham Abdominal muscle and quadriceps strength in chronic obstructive pulmonary disease Thorax, September 1, 2005; 60(9): 718 - 722. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. M. A. Calverley Long-acting inhaled bronchodilators in COPD: how many drugs do we need? Eur. Respir. J., August 1, 2005; 26(2): 190 - 191. [Full Text] [PDF]
|
|
|
|
|
|
N. S. Hopkinson, T. P. Toma, D. M. Hansell, P. Goldstraw, J. Moxham, D. M. Geddes, and M. I. Polkey Effect of Bronchoscopic Lung Volume Reduction on Dynamic Hyperinflation and Exercise in Emphysema Am. J. Respir. Crit. Care Med., March 1, 2005; 171(5): 453 - 460. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. Palange, G. Valli, P. Onorati, R. Antonucci, P. Paoletti, A. Rosato, F. Manfredi, and P. Serra Effect of heliox on lung dynamic hyperinflation, dyspnea, and exercise endurance capacity in COPD patients J Appl Physiol, November 1, 2004; 97(5): 1637 - 1642. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P M A Calverley Breathlessness during exercise in COPD: how do the drugs work? Thorax, June 1, 2004; 59(6): 455 - 457. [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS | REGISTER |
