Acid-Base curve nomogram for dog blood

Abstract

Pooled canine blood of different hemoglobin concentration was equilibrated with two carbon dioxide tensions and the resulting pH's of the samples were measured at 38°C. Readings obtained provided data for the construction of a cartesian nomogram for the dog, based on the pH/logpCO₂ coordinate system. The nomogram can be used to evaluate both respiratory and non-respiratory acid-base parameters. For contrast, a control nomogram on human blood was also constructed. Both nomograms show broad similarity. This is to be expected as the normal criteria used to define base excess relating to dog blood are the same as those used for human blood. Nonetheless, base excess and buffer base calculations using the nomogram for the dog and that for man show a deviation of 2.5–10%, and we consider this deviation to be more due to a species difference than to any summated experimental error.