Buffer Capacities of Human Blood and Plasma

Normal values for buffer capacity of blood and plasma of a number of normal subjects over various intervals between pH 7.5 and 6.1 were determined. The buffer capacities of blood and plasma were 38.5 and 16.1 mEq/L/pH respectively at physiologic pH values. Normal blood and plasma buffer capacities were relatively constant from pH 7.4-6.6. The buffer capacity of plasma proteins was found to be greater than that of bicarbonate at physiologic pH range. Variations of buffer capacity caused by certain disease processes are reported and discussed.