Abstract
In chronic air-flow obstruction (CAO), inspiratory mechanics constitute a potential mechanism of compensation for limitation of expiratory air flow. We sought to determine whether assessment of inspiratory function could improve our ability to predict ventilation at maximal exercise (V̇e max) in patients with CAO. Resting inspiratory and expiratory pulmonary function studies from 20 patients with ventilatory limitation of exercise due to CAO provided data for development of a new regression model for V̇e max. Maximal exercise was quantitated from breath-by-breath analysis of exercise responses at cycle ergometry with work increments of 25 watts each min to tolerance. Multiple regression analysis by 3 methods gave identical results. A 2-variable formula containing peak inspiratory flow rate (PIFR) and the forced expiratory volume in one second (FEV1) correlated strongly with V̇e max (r = 0.967) in the formula V̇e max (L/min) = 21.34 FEV1 (L) + 6.28 PIFR (L/s) + 3.94 (95% Cl = ± 18 L/min). This model was significantly different from published models containing FEV1 alone (p = 0.0002) and was not improved by additional variables. Similar formulas derived for emphysematous and bronchitic clinical types of CAO did not exhibit significantly different slope and intercept coefficients. Both PIFR and FEV1 correlated strongly with tidal volume at maximal exercise. The PIFR also correlated well with resting peak inspiratory airway pressure (r = 0.775). We conclude that considerations of PIFR in addition to FEV1 can improve our clinically ability to predict V̇e max in patients with CAO.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 230-235 |
| Number of pages | 6 |
| Journal | American Review of Respiratory Disease |
| Volume | 132 |
| Issue number | 2 |
| State | Published - Jan 1 1985 |
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ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine
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Prediction of ventilation at maximal exercise in chronic air-flow obstruction. / Dillard, T. A.; Piantadosi, S.; Rajagopal, K. R.
In: American Review of Respiratory Disease, Vol. 132, No. 2, 01.01.1985, p. 230-235.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Prediction of ventilation at maximal exercise in chronic air-flow obstruction
AU - Dillard, T. A.
AU - Piantadosi, S.
AU - Rajagopal, K. R.
PY - 1985/1/1
Y1 - 1985/1/1
N2 - In chronic air-flow obstruction (CAO), inspiratory mechanics constitute a potential mechanism of compensation for limitation of expiratory air flow. We sought to determine whether assessment of inspiratory function could improve our ability to predict ventilation at maximal exercise (V̇e max) in patients with CAO. Resting inspiratory and expiratory pulmonary function studies from 20 patients with ventilatory limitation of exercise due to CAO provided data for development of a new regression model for V̇e max. Maximal exercise was quantitated from breath-by-breath analysis of exercise responses at cycle ergometry with work increments of 25 watts each min to tolerance. Multiple regression analysis by 3 methods gave identical results. A 2-variable formula containing peak inspiratory flow rate (PIFR) and the forced expiratory volume in one second (FEV1) correlated strongly with V̇e max (r = 0.967) in the formula V̇e max (L/min) = 21.34 FEV1 (L) + 6.28 PIFR (L/s) + 3.94 (95% Cl = ± 18 L/min). This model was significantly different from published models containing FEV1 alone (p = 0.0002) and was not improved by additional variables. Similar formulas derived for emphysematous and bronchitic clinical types of CAO did not exhibit significantly different slope and intercept coefficients. Both PIFR and FEV1 correlated strongly with tidal volume at maximal exercise. The PIFR also correlated well with resting peak inspiratory airway pressure (r = 0.775). We conclude that considerations of PIFR in addition to FEV1 can improve our clinically ability to predict V̇e max in patients with CAO.
AB - In chronic air-flow obstruction (CAO), inspiratory mechanics constitute a potential mechanism of compensation for limitation of expiratory air flow. We sought to determine whether assessment of inspiratory function could improve our ability to predict ventilation at maximal exercise (V̇e max) in patients with CAO. Resting inspiratory and expiratory pulmonary function studies from 20 patients with ventilatory limitation of exercise due to CAO provided data for development of a new regression model for V̇e max. Maximal exercise was quantitated from breath-by-breath analysis of exercise responses at cycle ergometry with work increments of 25 watts each min to tolerance. Multiple regression analysis by 3 methods gave identical results. A 2-variable formula containing peak inspiratory flow rate (PIFR) and the forced expiratory volume in one second (FEV1) correlated strongly with V̇e max (r = 0.967) in the formula V̇e max (L/min) = 21.34 FEV1 (L) + 6.28 PIFR (L/s) + 3.94 (95% Cl = ± 18 L/min). This model was significantly different from published models containing FEV1 alone (p = 0.0002) and was not improved by additional variables. Similar formulas derived for emphysematous and bronchitic clinical types of CAO did not exhibit significantly different slope and intercept coefficients. Both PIFR and FEV1 correlated strongly with tidal volume at maximal exercise. The PIFR also correlated well with resting peak inspiratory airway pressure (r = 0.775). We conclude that considerations of PIFR in addition to FEV1 can improve our clinically ability to predict V̇e max in patients with CAO.
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UR - http://www.scopus.com/inward/citedby.url?scp=0021997236&partnerID=8YFLogxK
M3 - Article
C2 - 4026047
AN - SCOPUS:0021997236
VL - 132
SP - 230
EP - 235
JO - American Journal of Respiratory and Critical Care Medicine
JF - American Journal of Respiratory and Critical Care Medicine
SN - 1073-449X
IS - 2
ER -