Effects of Salmeterol on Walking Capacity in Patients With COPD

• Endurance time during an endurance shuttle walk [ Time Frame: acute response (2.5 hours) following the administration of the active and comparison drug ]
  

• Dyspnea during endurance shuttle walk [ Time Frame: acute response following the administration of the study medication ]
  
• cardio-respiratory responses during an endurance shutlle walk [ Time Frame: acute response following the administration of the study medication ]
  

Background: Little is known about the responsiveness of the endurance shuttle walking test (ESWT) to pharmacotherapy in patients with chronic obstructive pulmonary disease (COPD). This exercise testing modality needs to be further investigated because of its relevance for activity of daily living.

Objective: To evaluate, in patients with COPD, the responsiveness of the ESWT to detect improvement in walking performance after single dose of salmeterol.

Methods: In a randomised, double-blind, placebo-controlled, crossover study, 20 patients with COPD will perform, on two separate days, an ESWT at 80% of peak capacity, 2 hours after inhaling either a placebo or 50µg of salmeterol. Cardiorespiratory parameters will be monitored breath-by-breath during each walking test with a portable telemetric gas analyzer (Oxycom Mobile, Jaeger, Germany). Inspiratory capacities and Borg ratings for dyspnea were obtained every other minute throughout the tests.

Planned analysis. The main outcome will be endurance time. This variable will be compared between the two treatment arms using a paired t test. The time course of the cardiorespiratory parameters and dyspnea over time will be compared between the two exercise modalities. Comparisons will be done using a repeated measure design (ANOVA). Significance level will be set at a p value of 0.05.