Journal of Applied Physiology, Vol 60, Issue 1 1-8, Copyright © 1986 by American Physiological Society
Blood-gas equilibrium of carbon dioxide in lungs: a continuing controversy
J. Piiper
This review presents the experimental evidence that has been published in
recent years both against and in support of the occurrence of negative
blood-gas CO2 partial pressure differences (delta PCO2) in lungs in
rebreathing equilibrium and during steady-state gas exchange in
hypercapnia. Although some sources of potential experimental error can be
pointed out, the reasons for the remarkably pronounced disagreement between
the experimental data of the different studies cannot be definitely
identified. Since a consistent and reproducible occurrence of negative
blood-gas delta PCO2 in lungs in gas-blood equilibrium is not convincingly
proved, it appears to be justified to continue accepting the validity of
the conventional concept of equal PCO2 in blood and gas in equilibrium.
Because the issue is of considerable importance in the analysis and
understanding of alveolar gas exchange, pertinent evidence is expected from
future work.
