Use of facemask and mouthpiece to assess constant-workrate exercise capacity in COPD.
OBJECTIVE
To compare the response to constant-workrate cycling exercise between the mouthpiece and the facemask in patients with chronic obstructive pulmonary disease (COPD).


METHODS
Ten patients with COPD (FEV1: 48 +/- 14% pred, mean +/- SD) performed two symptom-limited constant-workrate cycling exercise tests at 80% of their predetermined peak exercise capacity. One test was performed using a mouthpiece and the other with a facemask, in a random order. The endurance time to constant-workrate exercise was compared between the two interfaces. VO2, VCO2, ventilation (VE), inspiratory capacity, dyspnea Borg score, and heart rate responses during exercise were also compared.


RESULTS
Endurance time was similar between the two interfaces (mean difference +/- SD, 30 +/- 74 s, P = 0.23). Except for the end-exercise values, which were lower with the facemask, the VO2, VCO2, and VE responses to submaximal exercise were similar between the two interfaces. Perception of dyspnea, inspiratory capacity, and heart rate kinetics were similar during the two exercise tests. No clear preference about either interface was expressed by the patients.


CONCLUSIONS
The mouthpiece and the facemask can be used with comparable results to determine the endurance time to constant-workrate cycling exercise in patients with COPD. Compared with the mouthpiece, the end-exercise values for VO2, VCO2, and VE were underestimated when a facemask was used. The similar responses in heart rate and symptom perception suggest that this could be due to an air leak at end-exercise with the facemask.
Centre de recherche, Hôpital Laval, Institut de Cardiologie et de Pneumologie de Québec, Département de Médecine, Université Laval, Québec, Canada.
Didier
D
Saey
Véronique
V
Pepin
Julie
J
Brodeur
Jessica
J
Lizotte
Philippe
P
Gagnon
Louis
L
Laviolette
Eric
E
Nadreau
Pierre
P
Leblanc
François
F
Maltais
D000368:Aged; D001642:Bicycling / Q000502:physiology; D005080:Exercise Test; D006801:Humans; D008297:Male; D008397:Masks; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology*; D011659:Pulmonary Gas Exchange / Q000502:physiology*; D012123:Pulmonary Ventilation; D012129:Respiratory Function Tests / Q000295:instrumentation*