THE VANSLYKE EQUATION (REPRINTED FROM SCAND J CLIN LAB INVEST, VOL 37, PG 15-19, 1977)

The Henderson-Hasselbalch equation has always occupied a central place in the description of the acid-base status of the blood. An equation of similar importance is the equation for the CO, equilibration curve of blood in vitro. It is proposed to name this the Van Slyke equation: a - 24.4 = -(2.3 x b + 7.7) x (c - 7.40) + d/(1 - 0.023 x b), where a = bicarbonate concentration in plasma/(mmol/l), b = hemoglobin concen tration in blood/(mmol/l), c = pH of plasma at 37-degrees-C, d = base excess concentration in blood/(mmol/l). These two equations provide an arithmetic algorithm for calculation of the various acid-base variabl es of the blood after measuring the pH, the pCO2, and the hemoglobin c oncentration