Preservation of normal human plasma in the liquid state; clinical, chemical, and physicochemical studies during three years of storage at room temperature.

By EUGENE L. LOZNER, f Ccmmander, Medical Corps, U.S.N . R., SONIA LEMISH, Lieutenant, H(W), U.S.N.R., A. SUE CAMPBELL, Lieutenant (junior grade), H(W), U.S.N.R., AND LLOYD R. NEWHOUSER, Captain, Medical Corps, U.S.N. N OTWITHSTANDING the fact that liquid plasma is a goad bacterial culture medium (even when containing hacteriostatic agents in clinically nontoxic concentrations), it remains a popular form for preservation because its preparation is simple and economical and because it is the only form in which the plasma is instantly available. It has been shown by many investigators, first by Kartashevsky and Filatov in Russia in 1934,i that plasma may be preserved in the liquid state for many months and administered with clinical safety. Recent workers in this field have emphasized the need for meticulous asepsis in the technics used in drawing blood and preparing plasma. A closed-vacuum” system has been advocated by several investigators ‘ and has much to recommend it. In this regard, it is pertinent to call attention to a recent report on the sterilization of citrated plasma by filtration,6 a procedure which may considerably increase the safety of a liquid plasma program. Previous papers from this Institute3’78 have presented the results of clinical, physiological, and chemical studies on plasma preserved in the liquid state at room temperature for two years. The conclusion of these studies was that when liquid plasma is properly prepared it may after such an extended period of storage be administered to patients with safety and benefit despite the inactivation within six months of certain labile constituents and a slow increase in nonprotein and alphaamino nitrogen content. It was pointed out in one of the papers8 that gross cleavages in the plasma proteirs might have occurred without significant increase in nonprotein nitrogen as long as the products of such cleavage remained large enough to be insoluble in the usual protein precipitant. For this reason physicochemical methods were employed in order to demonstrate whether or not such cleavages were taking place. It is the purpose of the present communication to report the results of osmometric, viscosimetric, and electrophoretic studies on plasma stored for three years in the liquid state and to summarize the chemical and clinical observations to date. The practical application of these studies is clear-cut; they form