Anestéziológia a intenzívna medicína 2/2013

Acid-base balance (acid-base)

There are three widely used approaches that describe acid-base abnormalities. The traditional bicarbonate approach has centered on the Henderson-Hasselbalch equation, relating pH to relative concentrations of HCO3 - to H2CO. The importance of nonbicarbonated buffers was recognised Van Slyke and then by Siggard-Anderson and coll., who developed the concept of base – excess. More recently, Stewart and Fencl proposed and developed the physical chemical concept based on the laws of electrical neutrality and conservation of mass governing water dissociation. Each approach differs only in assessment of the metabolic component, all three treat pCO2 as an independent variable. Because all three approaches give identical results, we should accept strong ion difference (SID), and strong ion gap (SIG) as „common currency“ between them.

Keywords: Acid-base balance, bicarbonate approach, base – excess approach, physical-chemical approach, SID, SIG.