Nonlinear increases in diffusing capacity during exercise by seated and supine subjects.

To study the effects of exercise on pulmonary diffusing capacity, we measured the lungs' diffusing capacity for carbon monoxide (DLCO) during exhalation from 30 to 45% exhaled vital capacity in eight healthy subjects at rest and during exercise while both sitting and supine. We found that DLCO at these lung volumes in resting subjects was 26.3 +/- 3.2% (mean +/- SE) higher in the supine than in the sitting position (P less than 0.001). We also found that, in both positions, DLCO at these lung volumes increased significantly (P less than 0.001) with increasing exercise and approached similar values at maximal exercise. The pattern of increase in DLCO with an increase in oxygen consumption in both positions was curvilinear in that the rate of increase in DLCO during mild exercise was greater than the rate of increase in DLCO during heavy exercise (P = 0.02). Furthermore, in the supine position during exercise, it appeared that DLCO reached a physiological maximum.

[1]  D. Cotton,et al.  A Theoretical Analysis of the Single Breath Diffusing Capacity for Carbon Monoxide , 1980, IEEE Transactions on Biomedical Engineering.

[2]  J. Nadel,et al.  Pulmonary diffusing capacity measured at multiple intervals during a single exhalation in man. , 1977, Journal of applied physiology: respiratory, environmental and exercise physiology.

[3]  C. Goresky,et al.  Effect of Exercise on Dilution Estimates of Extravascular Lung Water and on the Carbon Monoxide Diffusing Capacity in Normal Adults , 1975, Circulation research.

[4]  B Bake,et al.  Effect of inspiratory flow rate on regional distribution of inspired gas. , 1974, Journal of applied physiology.

[5]  N. Staub,et al.  Indirect and direct capillary blood volume in anesthetized open-thorax cats. , 1973, Journal of applied physiology.

[6]  R. Rogers,et al.  Pulsatile uptake of CO in the human lung. , 1970, The Journal of clinical investigation.

[7]  N. Anthonisen,et al.  Effect of expiratory flow rate on emptying of lung regions. , 1969, Journal of applied physiology.

[8]  N. Anthonisen,et al.  Effect of inspiratory flow rate on regional distribution of inspired gas. , 1969, Journal of applied physiology.

[9]  P. Sutherland,et al.  Previous volume history of the lung and regional distribution of gas. , 1968, Journal of applied physiology.

[10]  J. West,et al.  Transmission of Pulsatile Blood Pressure and Flow through the Isolated Lung , 1968, Circulation research.

[11]  R. Karp,et al.  Regulation of Pulmonary Capillary Blood Volume by Pulmonary Arterial and Left Atrial Pressures , 1968, Circulation research.

[12]  D V Bates,et al.  Regional distribution of ventilation and perfusion as a function of body position. , 1966, Journal of applied physiology.

[13]  J. Miller,et al.  Effect of lung inflation on pulmonary diffusing capacity at rest and exercise. , 1966, The Journal of clinical investigation.

[14]  A. Holmgren,et al.  On the Variation of DLCO with Increasing Oxygen Uptake during Exercise in Healthy Ordinarily Untrained Young Men and Women , 1965 .

[15]  A. Holmgren.  On the variation of D-LCO with increasing oxygen uptake during exercise in healthy trained young men and women. , 1965, Acta physiologica Scandinavica.

[16]  A. Fishman,et al.  Effect of exercise on pulmonary diffusing capacity , 1963, Journal of applied physiology.

[17]  F. Meade,et al.  A theoretical and experimental analysis of anomalies in the estimation of pulmonary diffusing capacity by the single breath method. , 1961, Quarterly journal of experimental physiology and cognate medical sciences.

[18]  L. Dexter,et al.  The pulmonary blood volume in man. , 1961, The Journal of clinical investigation.

[19]  R. Forster,et al.  Pulmonary capillary blood volume, flow and diffusing capacity during exercise. , 1960, Journal of applied physiology.

[20]  D. Bates,et al.  Influence of age on pulmonary diffusing capacity , 1959 .

[21]  Joseph C. Ross,et al.  A study of the mechanism by which exercise increases the pulmonary diffusing capacity for carbon monoxide. , 1958, The Journal of clinical investigation.

[22]  F. E. Noe,et al.  The measurement of pulmonary capillary blood volume and pulmonary membrane diffusing capacity in normal subjects; the effects of exercise and position. , 1958, The Journal of clinical investigation.

[23]  F. Roughton,et al.  Relative importance of diffusion and chemical reaction rates in determining rate of exchange of gases in the human lung, with special reference to true diffusing capacity of pulmonary membrane and volume of blood in the lung capillaries. , 1957, Journal of applied physiology.

[24]  G. Wright,et al.  Carbon monoxide uptake and pulmonary diffusing capacity in normal subjects at rest and during exercise. , 1954, The Journal of clinical investigation.

[25]  B. W. Armstrong,et al.  Maximal diffusing capacity of the lungs. , 1954, Journal of applied physiology.

[26]  J. Widimský,et al.  Lung-transfer factor at maximal effort in healthy men. , 1973, Respiration; international review of thoracic diseases.

[27]  J. Nadel,et al.  Physiologic diagnosis of subclinical emphysema. , 1973, The American review of respiratory disease.

[28]  C. Wooley,et al.  Right and left ventricular systolic time intervals. Effects of heart rate, respiration and atrial pacing. , 1971, The American journal of cardiology.

[29]  J. West,et al.  Measurements of capillary dimensions and blood volume in rapidly frozen lungs. , 1969, Journal of applied physiology.

[30]  A. Holmgren,et al.  On the variation of D-LCO with increasing oxygen uptake during exercise in healthy ordinarily untrained young men and women. , 1965, Acta physiologica Scandinavica.