TY - JOUR T1 - Does dynamic hyperinflation contribute to dyspnoea during exercise in patients with COPD? JF - European Respiratory Journal JO - Eur Respir J DO - 10.1183/09031936.00157711 SP - erj01577-2011 AU - J.A. Guenette AU - K.A. Webb AU - D.E. O'Donnell Y1 - 2012/01/01 UR - http://erj.ersjournals.com/content/early/2011/12/16/09031936.00157711.abstract N2 - Dynamic hyperinflation (DH) during exercise occurs in most but not all patients with advanced COPD. It is not known whether the presence or absence of DH has implications for dyspnoea and exercise tolerance. Therefore, we compared detailed ventilatory and sensory responses to exercise in hyperinflators and non-hyperinflators with moderate to severe COPD.Non-hyperinflators (n=65) were retrospectively identified from a sample of 427 patients and case-matched to a group of hyperinflators (n=65) based on sex, age, body mass index and %predicted forced expiratory volume in 1 second. Resting pulmonary function and constant work rate cycle exercise responses were compared.Hyperinflators decreased inspiratory capacity (IC) from rest to peak exercise by 0.46±0.24 L whereas the non-hyperinflators increased IC by 0.10±0.15 L (P<0.0001). There were no significant group differences in endurance time (9.11±5.98 vs. 8.87±5.24 min) or dyspnoea intensity for any given time or ventilation. An inflection in tidal volume versus ventilation occurred in the majority of non-hyperinflators (n=61) and hyperinflators (n=62) at a similar time and ventilation. Mechanical constraints on tidal volume expansion and the attendant rise in dyspnoea intensity were similar in both groups.Dyspnoea intensity during exercise was associated with progressive mechanical constraints on tidal volume expansion regardless of the presence of DH. ER -