Journal of Applied Physiology, Vol 48, Issue 1 66-71, Copyright © 1980 by American Physiological Society
Analysis of rebreathing measurements of pulmonary tissue volume in pulmonary edema
M. Friedman, S. H. Kaufman and S. A. Wilkins Jr
A rebreathing method (usood volume (VTPC) was evaluated in 13 dogs. In
seven, pulmonary edema was induced by oleic acid injection. Six dogs served
as controls. Values of VTPC calculated by three algorithms were compared to
postmortem lung water. The first algorithm uses the C18O intercept to
determine time 0 and all data to construct the alveolar disappearance
curves. The second uses the beginning of inspiration as time 0. The last
uses data only during the last third of expiration. The best correlation (r
= 0.90) between VTPC and total lung water was obtained utilizing the first
algorithm. In the control animals, mean VTPC was 188 ml, and in the edema
dogs was 278 ml. Mean VTPC for all dogs was 96 +/- 14% of total lung water
using the first algorithm. Another algorithm (J. Appl. Physiol.: Respirat.
Environ. Exercise Physiol. 44: 782-795, 1978) was evaluated inthe edema dog
group. This method gave values of VTPC 53% higher than those obtained by
the first algorithm.
