Similar Dynamic Hyperinflation During Arm And Leg Exercise At Similar Ventilation In COPD

Abstract

Corresponding author's email: J.Hannink@elg.umcn.nlPatients with COPD report more dyspnea during arm than during leg exercise. One of the major causes of dyspnea is dynamic Purpose: hyperinflation (DH), which is caused by airflow limitation as well as increase in ventilation. The aim of our study was to compare DH at equal ventilation (isoventilation) during arm and leg work and to investigate the effects of breathing pattern on DH.: Thirteen clinically stable patients with mild-to-very severe COPD (FEV 59±6%) participated in this study. Arm and leg constant Methods 1 work rate (CWR) ergometry were performed in random order with ventilation equal to that at 50% of peak arm load. The corresponding leg load of that level of ventilation was determined from the incremental leg test. Respiratory physiology was measured breath-by-breath. Change in inspiratory capacity, measured at rest and at 2min intervals, was used to reflect DH.At steady state isoventilation (37±2 and 36±2L/min for arm and leg CWR tests respectively, p>0.05), arm load was 29±5Watt and Results: leg load 52±6Watt (p<0.001). The level of DH, 0.32±0.09 and 0.27±0.08L during arm and leg exercise respectively, was not significantly different ( Figure 1). However, breathing frequency was greater during arm than during leg exercise (24±1 versus 21±1breaths/min, p<0.01) (Figure 2) and the opposite was true for tidal volume (1.56±0.15 versus 1.69±0.14L, p<0.01).At similar ventilation, we found a similar degree of DH during arm and leg CWR tests in patients with mild-to-very severe Conclusion: COPD. Although differences in breathing pattern were observed between arm and leg exercise, these did not affect the level of DH. Figure 1. Inspiratory capacity during isoventilation leg and arm constant work rate ergometry.