P37 Wearable devices reveal impaired respiratory and cardiovascular responses to clinical assessments and activities during daily life in people with chronic obstructive pulmonary disease
Morkos D[1], McNamara RJ[2, 3], McKenzie DK[3, 4], Gandevia S[4, 5] and Brodie MA[1, 5]
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, Australia
- Department of Physiotherapy, Prince of Wales Hospital, Randwick, Australia.
- Department of Respiratory and Sleep Medicine, Prince of Wales Hospital, Randwick, Australia.
- Faculty of Medicine, University of New South Wales, Kensington, Australia
- NeuRA, Sydney, Australia
Chronic obstructive pulmonary disease (COPD) is a progressive lung disease. Patients with COPD often seek medical attention several times a year for exacerbation of their symptoms. [1] This study examines respiratory rate and heart rate changes in response to exercise. The hypotheses tested are: (i) People with COPD will have impaired physiological responses to exercise assessments; (ii) disease severity will affect activities of daily living (ADLs).
Twenty-five participants were recruited (n=9 moderate-COPD; n=10 severe-COPD; n=6 healthy-age-matched). Participants wore the Zephyr Bioharness (chest strap) during clinical assessments (including a 6-minute-walk-test) and for 36 hours of free-living.
Both clinical assessments and ADLs induced time-dependent increases in respiratory and heart rates (dependent on exercise duration and intensity). During clinical assessments: (i) People with more severe COPD had significantly (p<0.05) shorter 6-minute-walk-test distances (366 versus 477 meters) and lower blood oxygen levels (90% versus 96% SPO2); (ii) increased disease severity (lower FEV1 % predicted) correlated with more elevated respiratory rates (r=-0.40, p=0.04) but less elevated heart rates (r=0.73, p=0.002). During ADLs, people with more severe COPD did significantly less high intensity ADLs (0.6 versus 1.7 hours), but had higher respiratory rates (21 versus 17 BPM).
Physiological responses to exercise (clinical and ADLs) may be impaired by COPD; despite increased breathing rates, people with more severe COPD had lower exercise capacity, blood oxygen concentrations and less elevated heart rates. The concurrent measurement of physical activity, respiratory rate and heart rate may enable early detection of changes in health-status for people with COPD.
- Bertens, L.C., et al., Development and validation of a model to predict the risk of exacerbations in chronic obstructive pulmonary disease. Int J Chron Obstruct Pulmon Dis, 2013. 8: p. 493-9.