Effects of Gas-density On Pulmonary Gas-exchange of Normal Man At Rest and During Exercise

Changes in the physical properties of inspired gas might be expected to influence the distribution of ventilation in the lungs as well as the diffusive and convective (cardiogenic) mixing of inspired gas with lung residual gas, thus possibly affecting pulmonary gas exchange for O2 and CO2. The purpose of our work was to assess to what extent this occurs in practise in human subjects, who could compensate for the changes directly brought about by altering the physical characteristics of the inhaled gas by changing their breathing pattern.