Computerized correction of blood base excess to full hemoglobin-O₂ saturation

A mathematical procedure was developed to obtain an accurate coefficient (-∆BE_B) for the correction of blood base excess to full hemoglobin-O₂ saturation taking into account actual 2,3-diphosphoglycerate (2,3-DPG) concentration.

Previously published laboratory data were carefully processed through regression analysis, by correlating laboratory measurements of -∆BE_B with the corresponding values of plasma pH, CO₂ tension and 2,3-DPG.

Data processing allowed the development of two accurate fits to the original laboratory results for blood with normal 2,3-DPG and for blood depleted of 2,3-DPG (r² = 0.990 and 0.986, respectively, p < 0.0001 for both), as the main components of a procedure for estimating the correction factor in normal conditions and in moderate-to-extreme illness with extreme acid-base abnormalities.

This regression-derived procedure can easily integrate any computer system to automatically obtain an accurate correction factor on the basis of plasma pH, CO₂ tension, and 2,3-DPG concentration if available. It may also allow for the assessment of small stoichiometric quantities involved in O₂-linked H⁺ exchange and equilibrium (Haldane effect) in computer programs dedicated to these types of investigations.