Estimation of total carbon dioxide contents in canine coronary arterial and venous whole blood samples.

We examined whether total carbon dioxide content (CCO2) estimation equations for human whole blood in the literature are applicable to canine coronary arterial and venous blood samples. PCO2 of the tested blood samples covered 19-52 mmHg; PO2 19-398 mmHg. Three CCO2 estimation equations developed by Kelman, Godfrey, and Douglas et al yielded CCO2 values over a range of 26.7-54.9 vol%, where plasma CCO2 values calculated by the Henderson-Hasselbalch equation ranged over 27.7-62.2 vol%. The estimated blood CCO2 values were almost identical among the three equations. They also closely correlated with plasma CCO2 values measured after hemolysis with saponin. We conclude that the human whole blood CCO2 estimation equations are applicable to canine coronary arterial and venous blood samples. These CCO2 equations may be used for canine cardiac metabolic studies.