The determination of ammonia in arterial and venous blood by immediate fixation.

Abstract

SUMMARYA method for determination of blood ammonia was devised by fixing the blood with a trichloroacetic acid solution within 1 sec after shedding. The ammonia value using this technique was much lower than using whole blood in the assay of the same sample, while the recovery of the nitrogen added to the whole blood was 100%. The minimum ammonia value was obtained immediately after shedding by our method, and in 30 normal subjects the values for venous blood ammonia were 0.62 ± 0.22 μig ammonia nitrogen per ml and in 12 normal subjects the values for arterial blood ammonia were 0.52 ± 0.28 μg ammonia nitrogen per ml. According to our method, the blood specimens mixed with trichloroacetic acid and standing at 0° did not change its ammonia content after 1 hour, and the value for supernatant of blood extracted with trichloroacetic acid was also unchanged at –20° after more than 24 hours.Ammonia values of arterial and venous blood were determined in patients with various diseases or liver diseases. The values of patients without liver dysfunction were almost within normal range while those with liver disease showed little higher than normal. Ammonia determination of blood and cerebrospinal fluid was performed in patients with Inose type of the hepatocerebral disease and their values almost always exceeded the normal levels.