Abstract
We previously observed an increase in minute ventilation (V̇E) with resistive unloading (He-O2 breathing) in healthy elderly subjects with normal pulmonary function. To investigate the effects of resistive unloading in elderly subjects with mild chronic airflow limitation (FEV1/FVC: 61 ± 4%), we studied 10 elderly men and women 70 ± 3 yr of age. These subjects performed graded cycle ergometry to exhaustion, once breathing room air and once breathing a He-O2 gas mixture (79% He, 21% O2). V̇E, pulmonary mechanics, and PETCO2 were measured during each 1-min increment in work rate. Data were analyzed by paired t test at rest, at ventilator/threshold (VTh), and during maximal exercise. V̇E was significantly (p < 0.05) increased at VTh (3.4 ± 4.0 L/min or 12 ± 15% increase) and maximal exercise (15.2 ± 9.7 L/min or 22 ± 13% increase) while breathing He-O2. Concomitant to the increase in V̇E, PETCO2 was decreased at all levels (p < 0.01), whereas total work of breathing against the lung was not different. We concluded that V̇E is increased during He-O2 breathing because of resistive unloading of the airways and the maintenance of the relationship between the work of breathing and exercise work rate.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1128-1134 |
| Number of pages | 7 |
| Journal | American Journal of Respiratory and Critical Care Medicine |
| Volume | 163 |
| Issue number | 5 |
| State | Published - 2001 |
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ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine
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Breathing He-O2 increases ventilation but does not decrease the work of breathing during exercise. / Babb, T. G.
In: American Journal of Respiratory and Critical Care Medicine, Vol. 163, No. 5, 2001, p. 1128-1134.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Breathing He-O2 increases ventilation but does not decrease the work of breathing during exercise
AU - Babb, T. G.
PY - 2001
Y1 - 2001
N2 - We previously observed an increase in minute ventilation (V̇E) with resistive unloading (He-O2 breathing) in healthy elderly subjects with normal pulmonary function. To investigate the effects of resistive unloading in elderly subjects with mild chronic airflow limitation (FEV1/FVC: 61 ± 4%), we studied 10 elderly men and women 70 ± 3 yr of age. These subjects performed graded cycle ergometry to exhaustion, once breathing room air and once breathing a He-O2 gas mixture (79% He, 21% O2). V̇E, pulmonary mechanics, and PETCO2 were measured during each 1-min increment in work rate. Data were analyzed by paired t test at rest, at ventilator/threshold (VTh), and during maximal exercise. V̇E was significantly (p < 0.05) increased at VTh (3.4 ± 4.0 L/min or 12 ± 15% increase) and maximal exercise (15.2 ± 9.7 L/min or 22 ± 13% increase) while breathing He-O2. Concomitant to the increase in V̇E, PETCO2 was decreased at all levels (p < 0.01), whereas total work of breathing against the lung was not different. We concluded that V̇E is increased during He-O2 breathing because of resistive unloading of the airways and the maintenance of the relationship between the work of breathing and exercise work rate.
AB - We previously observed an increase in minute ventilation (V̇E) with resistive unloading (He-O2 breathing) in healthy elderly subjects with normal pulmonary function. To investigate the effects of resistive unloading in elderly subjects with mild chronic airflow limitation (FEV1/FVC: 61 ± 4%), we studied 10 elderly men and women 70 ± 3 yr of age. These subjects performed graded cycle ergometry to exhaustion, once breathing room air and once breathing a He-O2 gas mixture (79% He, 21% O2). V̇E, pulmonary mechanics, and PETCO2 were measured during each 1-min increment in work rate. Data were analyzed by paired t test at rest, at ventilator/threshold (VTh), and during maximal exercise. V̇E was significantly (p < 0.05) increased at VTh (3.4 ± 4.0 L/min or 12 ± 15% increase) and maximal exercise (15.2 ± 9.7 L/min or 22 ± 13% increase) while breathing He-O2. Concomitant to the increase in V̇E, PETCO2 was decreased at all levels (p < 0.01), whereas total work of breathing against the lung was not different. We concluded that V̇E is increased during He-O2 breathing because of resistive unloading of the airways and the maintenance of the relationship between the work of breathing and exercise work rate.
UR - http://www.scopus.com/inward/record.url?scp=0034744444&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0034744444&partnerID=8YFLogxK
M3 - Article
C2 - 11316648
AN - SCOPUS:0034744444
VL - 163
SP - 1128
EP - 1134
JO - American Journal of Respiratory and Critical Care Medicine
JF - American Journal of Respiratory and Critical Care Medicine
SN - 1073-449X
IS - 5
ER -