Journal of Applied Physiology, Vol 57, Issue 4 1167-1172, Copyright © 1984 by American Physiological Society
Influence of blood flow on cutaneous permeability to inert gas
Y. C. Lin, N. Kakitsuba, D. K. Watanabe and G. W. Mack
A thermally regulated Plexiglas chamber was designed for investigation of
transcutaneous diffusion of N2 and helium (He) in the human hand. Influence
of cutaneous blood flow in this process was studied simultaneously with gas
diffusion measurements. Changes in cutaneous blood flow (Q, in ml X min-1 X
100 ml tissue-1) were effected by altering ambient temperature (T) from 20
to 40 degrees C (Q = 0.08 X 100.07T). We found that the rate of inert gas
diffusion through human skin, expressed as conductance (G, in ml STPD X h-1
X m-2 X atm-1), increases exponentially as a function of blood flow, and
was indistinguishable between He and N2 (G = 21.19 X 100.0124Q). The
permeability, diffusion coefficient per unit diffusion distance (D/h, in
cm/h), also rose exponentially as a function of blood flow. But
permeability for He (D/h = 0.1748 X 100.0203Q) was greater than that for N2
(D/h = 0.1678 X 100.0114Q). As cutaneous blood flow rises, because of
increased temperature, the apparent diffusion distance falls linearly for
both N2 and He. The change is more prominent for He than for N2 diffusion.
Estimated replacement time for the body stores of N2 by transcutaneous
diffusion alone was shortened from 26.8 h at 31 degrees C to 15.1 h at 37
degrees C. It is suggested from this study that beneficial results may be
derived during decompression procedure 1) by maintaining an appropriate
transcutaneous pressure gradient of inert gases, and 2) by elevating
ambient temperature.
