EFFECT OF CS AEROSOL UPON LUNG GAS TRANSFER AND ALVEOLAR VOLUME IN HEALTHY MEN

Abstract

Measurements of transfer factor (Tl'), alveolar volume (VA') and KCO (transfer co‐efficient for carbon monoxide; Tl' ÷ VA') have been made by the single breath carbon monoxide method with a single breath determination of alveolar volume before and after exposure to CS aerosol on 11 volunteer servicemen. For each subject the study occupied 3 days of which the first and third were control and post exposure days respectively. The exposure to CS was on the morning of the second day for approximately 1 hr to a concentration which was increased progressively from about 0·6 to 2·0 mg m−3. During the study no changes were observed in the alveolar volume or its subdivisions, vital capacity and residual volume. The transfer factor and KCO were rather higher on the first control day before exposure than on the post exposure day, with the day of exposure intermnediate. Exposure to CS aerosol was followed immediately by an increase in transfer factor and subsequently by a transient decrease to below the initial value. The changes were of small magnitude and quite insufficient to exert any material effect upon gas exchange; they were probably due to variations in vasomotor tone asociated with the procedure affecting the distribution of body blood volume, including the volume of blood in the lung capillaries. © 1972 The Physiological Society