Ammonia Intoxication from Bank Blood in Patients with Cirrhosis of the Liver
STUDIES1–3 of ammonia intoxication in patients with cirrhosis of the liver have shown that the administration of drugs such as chlorothiazide,* acetazolamide,† and ammonium chloride, which have been used commonly in patients with ascites, may cause ammonia intoxication or may increase its severity if it exists. The increased ammonia content of stored blood has been reported,4–7 and in most clinical conditions is harmless. However, in the cirrhotic patient with hemorrhage that requires massive transfusion, the use of stored blood may precipitate coma because of its high ammonia concentration.
This study was undertaken to determine the rate of increase in ammonia nitrogen in stored blood for the purpose of predicting the ammonia content of blood administered in emergency situations, and for considering means of compensating for this difficulty.
Forty-two samples of whole blood, collected in 500-ml. containers‡ were stored at from 4 to 10° C. as long as 31 days. Analyses for ammonia nitrogen were made through the courtesy of W. R. Faulkner, Ph.D., of the Department of Clinical Pathology, whose modifications of the Conway technic were employed.
There was an average linear increase of 20 μg. per 100 ml. per day in the amount of ammonia nitrogen in stored blood (Fig. 1). In an attempt to explain the unusual values obtained for particular samples, the ease and rapidity of bleeding the donor were evaluated. Easy, rapid bleeding was associated with low values for ammonia; whereas, difficulties with venipuncture and stasis below a tourniquet were correlated with higher values.