The clinical application of simple method for determination of blood ammonia for various liver deseases

Abstract

The estimation of blood ammonia concentration is of great importance in the prediction of hepatic coma, as well as in the observation of clinical courses. Although various methods have been reported for the determination of blood ammonia levels, in case of an emergency, none of these methods is without problem, because of complicated procedures.
The authors have modified the simple and rapid method of Tada and Okuda, so that it is available for the screening of hyperammoniemia in a patient with hepatic failure in the field of internal medicine.
In this report, we determined blood ammonia levels with the previous method and with the above-mentioned simplified method in 451 cases on patients with chronic liver diseases in six hospitals, and obtained results as follows: correlation (r=0.829, y=0.89x+1.2), intraassay reproducibility in group more than 100μg/dl of ammonia level (C.V.=10%).
We confirm the usefulness of the newly developed reflectancemeter for determination of blood ammonia levels. The correlation, with the reflectancemeter and the enzymatic method, is observed as follows: (r=0.95, y=1.06x+2.1), intraassay reproducibility (C.V.=3.16%).