COPD Patients Have a Restricted Breathing Pattern That Persists with Increased Metabolic Demands. Academic Article uri icon


  • A healthy respiratory system has variability from breath-to-breath and patients with COPD (PwCOPD) have abnormal variability in breath cycles. The aim of this study was to determine if interbreath-interval and tidal-volume variability, and airflow regularity change as metabolic demands increase (seated, standing, and walking) in PwCOPD as compared to controls. Sixteen PwCOPD (64.37.9yr, 61.344.1% FEV1%predicted) and 21 controls (60.26.8yr, 97.516.8% FEV1%predicted) sat, stood, and walked at their preferred-pace for five-minutes each while breathing patterns were recorded. The mean, standard deviation, and coefficient of variation of interbreath-intervals and tidal-volume, and the regularity (sample entropy) of airflow were quantified. Results were subjected to ANOVA analysis. Interbreath-interval means were shorter in PwCOPD compared to controls (p=0.04) and as metabolic demand increased (p<0.0001), standard deviation was decreased in PwCOPD compared to controls during each condition (p's<0.002). Mean tidal-volume did decrease as metabolic demand increased across groups (p<0.0001). Coefficient of variation findings (p=0.002) indicated PwCOPD decline in tidal-volume variability from sitting to standing to walking; whereas, controls do not. There was an interaction for airflow (p=0.02) indicating that although, PwCOPD had a more regular airflow across all conditions, control's airflow became more irregular as metabolic demand increased. PwCOPD's airflow was always more regular compared to controls (p=0.006); although, airflow became more irregular as metabolic demand increased (p<0.0001). Healthy respiratory systems have variability and irregularity from breath-to-breath decreases with adaptation to demand. PwCOPD have more regular and restricted breathing pattern that may affect their ability to adjust in demanding situations.

published proceedings

  • COPD

altmetric score

  • 2

author list (cited authors)

  • Yentes, J. M., Fallahtafti, F., Denton, W., & Rennard, S. I.

citation count

  • 4

complete list of authors

  • Yentes, Jennifer M||Fallahtafti, Farahnaz||Denton, William||Rennard, Stephen I

publication date

  • June 2020