Combined enzymatic assays for 3-hydroxybutyrate and lactate: end-point and kinetic methods.

The consecutive measurement of 3-hydroxybutyrate and lactate by enzymatic end-point and rapid kinetic methods is described. Using end-point analysis within batch coefficient of variation (C.V.) ranged from 0.5 to 6.5% depending on concentration, and between batch C.V. was 1.7 to 9.0%. In the rapid kinetic method C.V. ranged from 4.2 to 10.6%. Both assays showed absolute agreement with conventional spectrophotometric methods. The rapid kinetic method yields plasma values within 15 min of blood sampling and is suitable for use in emergency situations.