title: Gas exchange during exercise in healthy people. I. The physiological dead-space volume.
abstract: 1. Physiological dead-space volume (V D) was measured in twenty-four healthy men and women aged from 20 to 71 years, at rest and at two rates of work on a treadmill, whilst breathing air and breathing oxygen. 2. The effect of correction of arterial carbon dioxide tension (Pa,CO2) to pulmonary capillary temperature on the resulting value for V D was investigated. We find that the effect is substantial and that a correction should be made. 3. Equations have been derived for the prediction of normal V D during exercise. The best prediction was given by a regression on height, age, carbon dioxide output, ventilation and respiratory frequency, with an upper 95% confidence limit of +81 ml.
mesh_terms: D000328:Adult; D000368:Aged; D001831:Body Temperature; D002196:Capillaries / Q000502:physiology; D002245:Carbon Dioxide; D005260:Female; D006801:Humans; D008168:Lung / Q000098:blood supply; D008297:Male; D008875:Middle Aged; D010100:Oxygen; D005082:Physical Exertion; D012126:Respiratory Dead Space; D012737:Sex Factors; D013223:Statistics as Topic; D013990:Tidal Volume
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen