Journal of Applied Physiology, Vol 42, Issue 6 899-902, Copyright © 1977 by American Physiological Society
Effect of breathing helium-oxygen on static lung volumes and lung recoil in normal man
M. A. Hutcheon, J. R. Rodarte and R. E. Hyatt
Static lung volumes and static elastic recoil pressure (Pel) were measured
in normal subjects breathing air and 80% helium plus 20% oxygen (He+O2). In
22 subjects, He+O2 produced small but significant increases in total lung
capacity (TLC) (mean 0.11 liter, P less than 0.001) and residual volume
(mean 0.10 liter, P less than 0.01) without change in vital capacity or
functional residual capacity. The mechanisms for this change are obscure.
In 10 subjects, breathing He+O2 had no significant effect on Pel (paired
t-test) at any lung volume measured (50-80% TLC). In one subject, Pel at 70
and 80% TLC was significantly higher on air than on He+O2 (unpaired t-test,
P less than 0.05). Because changes in lung volumes and lung recoil were
small, we concluded that these effects do not negate the clinical utility
of He+O2 flow-volume curves.
