The effect of haemoglobin concentration

When blood is taken from a patient for examination of acid-base status, the haemoglobin concentration of the blood is also measured routinely. Blood from an anaemic patient, being less well buffered than normal blood, yields a line on the Siggaard-Andersen plot with a slope nearer to - 1 than normal blood. To calculate the contribution of the anaemia, it is necessary to introduce the concept of normal buffer base . The normal buffer base of a sample of 

To estimate the normal buffer base for a sample of blood giving a particular blood line, the procedure is to read off the corresponding base excess and the 

Observed buffer base = normal buffer base + observed base excess. 

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