A simple and rapid microdiffusion method for blood ammonia using a reflectance meter and a reagent plate, and its clinical evaluation for liver diseases.

A simple and rapid procedure using 20 microliters of whole blood is described for estimating blood ammonia by means of a reflectance meter using a reagent plate, which operates by the principle of microdiffusion. The most suitable condition for microdiffusion was at 37 degrees C for 15 min, in which the standard curve was linear, and reproducibility and recovery were sastisfactory. Blood ammonia levels by this method correlate significantly with the values by an ion exchange method in 72 patients with liver disease (r = + 0.970, y = 1.13x - 11). The method has a distinct advantage in sensitivity, simplicity, and rapidity for blood ammonia determination.