Changes in Blood and Urine after Intravenous Amino Acid Mixture in Patients with Liver Disease. ∗

Abstract

Recent reports of studies on patients show that mixtures of the essential amino acids, as obtained by enzymatic digestion of casein, can be used to maintain nitrogen balance when given intravenously.^1-6 The statement has been made, however, that in patients with liver disease the method is contraindicated. Our clinical experience does not support this conclusion and, although the question requires further study, the data acquired in the present experiments seem to have some relevancy.

Experimental Method. The solution of amino acids used (“Amigen”) was supplied by Dr. Warren M. Cox, Jr. of Mead Johnson and Company, and consisted of a sterilized aqueous nonpyrogenic 10% solution of an enzymatic hydrolysate of purified casein and pork pancreas. The nitrogen of the solution is present chiefly as nitrogen of amino acids and polypeptides, and the material is not allergenic. The solution contains the amino acids essential for maintenance and growth as shown by animal experiments. The hydrogen ion concentration of the solution was adjusted to a pH value of 6.5.

Amino acid concentration in whole blood and plasma was determined by the nin-hydrin-CO₂ method recently developed by Van Slyke, MacFadyen and Hamilton. 7 Amino acid concentration in urine was likewise determined by the ninhydrin-C02 technic devised by the same investigators but as yet unpublished.s Standard methods wereused in the other analyses.

The patients were kept under observation constantly during the study and in no case was it necessary to discontinue the infusion on account of untoward symptoms. The infusions were given through arm veins by steady drip, the rate being kept as nearly as possible the same in comparable experiments. Urine was collected without loss by means of an indwelling urethral catheter in the experiments of Table 11, while in the other cases the patients were able to void at stated intervals.