The Figge-Fencl Quantitative Physicochemical Model
of Human Acid-Base Physiology (Version 3.0)

by James J. Figge, MD, MBA, FACP

Copyright 2003 - 2013 James J. Figge.
Published 8 October, 2012; updated on 28 April, 2013; updated on 27 October, 2013;
on www.Figge-Fencl.org and www.acid-base.org.


Statistical Validation of the Figge-Fencl Quantitative Physicochemical Model
(Version 3.0)

albumin solutions

Figure 1. pH of albumin-containing solutions as calculated by the Figge-Fencl quantitative physicochemical model (version 3.0) (y-axis), versus measured pH (x-axis). Experimental data cover the pH range of 6.85 to 7.94. Experimental data (n = 65) are from Figge, Rossing and Fencl, J Lab Clin Med. 1991; 117: 453-467. The slope of the regression line is 1.0068 (98% confidence limits: 0.9672 to 1.0464). Thus, the slope is not significantly different than 1.0000. The intercept is -0.0469.
R = 0.99157, and R2 = 0.9832.


Paired t Test.

The mean difference, { Σ(calculated pH - measured pH) } / 65 = 0.0034 (+/- 0.0329 Standard Deviation).

The 98% confidence interval for the mean difference is calculated using: t (n-1, alpha/2) = 2.386; where n = 65; alpha=0.02.

The 98% confidence interval for the mean difference is 0.0034 +/- (2.386)(0.0329)/SQRT(65) = 0.0034 +/- 0.0097.

Hence, the mean difference is not statistically different than zero.


Link to Figge-Fencl Model Version 3.0

Link to Albumin Titration Curve (Model Version 3.0)

Link to Online Model 3.0 Application

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