AJP - Regulatory, Integrative and Comparative Physiology, Vol 244, Issue 4 492-R499, Copyright © 1983 by American Physiological Society
Theoretical analysis of "metabolic indices" of blood buffer system
T. Sato, N. Ikeda, H. Tsuruta and M. Shirataka
The well-known base excess (BE) and buffer base (BB) curves of
Siggaard-Andersen's nomogram are based on their empirical finding that the
blood buffer lines in the pH-log PCO2 coordinates with the same BE (or BB)
always pass through a single point irrespective of the hemoglobin
concentration. We have analytically derived the BE and BB curves on the
assumption of a two-compartmental model of blood buffer system comprised of
plasma and red blood cells. These hyperbolic functions of BE and BB curves
fitted the Siggaard-Andersen's observation very well. The simple formulas
derived from the buffer equation with the parameters obtained on the
least-square basis were shown to estimate "metabolic indices" of blood as
accurately as the computer reading of the nomographic curves. These results
seem to indicate that the buffer equation based on the two-compartmental
model describes the acid-base status of blood satisfactorily, and that it
can entirely replace the Siggaard-Andersen's nomogram.
