LUNG FUNCTION STUDIES. IV. POSTURAL CHANGES IN RESPIRATORY DEAD SPACE AND FUNCTIONAL RESIDUAL CAPACITY 1

Abstract

The respiratory dead space and dead space/tidal volume fraction, measured in 5 male subjects by continuous analysis of N2 concn. and volume flow of gas expired after O2 inhalation, decreased from respective avg. values of 147 ml. and 27.5% in the sitting posture, to 124 ml. and 24.5% semi-reclining, to 101 ml. and 18% supine. Functional residual capacity decreased from sitting to supine.