PT - JOURNAL ARTICLE AU - Véronique Pepin AU - Julie Brodeur AU - Yves Lacasse AU - Julie Milot AU - Pierre LeBlanc AU - François Whittom AU - François Maltais TI - Six-minute walking versus shuttle walking: responsiveness to bronchodilation in chronic obstructive pulmonary disease AID - 10.1136/thx.2006.065540 DP - 2007 Apr 01 TA - Thorax PG - 291--298 VI - 62 IP - 4 4099 - http://thorax.bmj.com/content/62/4/291.short 4100 - http://thorax.bmj.com/content/62/4/291.full SO - Thorax2007 Apr 01; 62 AB - Background: The responsiveness of the endurance shuttle walk to functional changes following bronchodilation has recently been reported. The current literature suggests that the 6 min walking test (6MWT) is less responsive to bronchodilation than the endurance shuttle walk.Aim: To compare bronchodilator-induced changes in exercise performance with the 6MWT and the endurance shuttle walk.Methods: In a randomised, double-blind, placebo-controlled, crossover trial, 14 patients with chronic obstructive pulmonary disease (forced expiratory volume in 1 s (FEV1) 50 (8)% predicted) completed two 6MWTs and two endurance shuttle walks, each preceded by nebulised placebo or 500 μg ipratropium bromide. Cardiorespiratory parameters were monitored during each walking test with a portable telemetric gas analyser. Quadriceps twitch force was measured by magnetic stimulation of the femoral nerve before and after each walking test.Results: The 6 min walking distance did not change significantly after bronchodilation despite a significant increase in FEV1 of 0.18 (0.09) litres (p<0.001). A similar change in FEV1 (0.18 (0.12) litres, p<0.001) was associated with a significant improvement in the distance walked on the endurance shuttle walk (Δdistance ipratropium bromide – placebo  =  144 (219) m, p = 0.03). Quadriceps muscle fatigue was infrequent (<15% of patients) after both walking tests.Conclusion: The endurance shuttle walk is more responsive than the 6MWT for detecting changes in exercise performance following bronchodilation.