The Importance of Volume and of Tonicity of the Body Fluids in Salt Depletion Shock 1

Abstract

It is not known whether the deterioration in circulatory efficiency which follows sodium chloride loss is related primarily to the hypotonicity, to the changes in the volume of fluid in the various compartments, or to both. In experimental salt depletion produced by means of the intraperitoneal injection and subsequent removal of glucose solution, both of these factors invariably coexist. As sodium and chloride ions enter the intraperitoneal fluid, water moves into the cells in response to osmotic forces. Diminution of the volume of extracellular fluid and plasma, swelling of the cells, and generalized hypotonicity are the inevitable end results (1, 2, 3). Since these changes occur rapidly and almost simultaneously, it is difficult to ascribe the primary causative role in the circulatory collapse which ensues to any one factor. It is conceivable, on theoretical grounds at least, that all of these changes are important. It is quite possible, for instance, that the hypotonic and swollen cells of the cardiovascular system become inefficient, while the blood thickens and becomes more difficult to move through the vessels.To clarify the relative significance of each of these changes in the production of salt depletion shock, further experiments have been conducted in which hypotonicity and the state of hydration of extracellular and cellular fluid have been altered in directions other than those seen in ordinary salt depletion. MATERIALS AND METHODSA. Dilution of the body fluids in nephrectomized animals. The effects of an infusion of 5 per cent glucose solution on the composition of the body fluids and the efficiency of the circulation were studied in 3 nephrectomized dogs on the day following removal of the second kidney. The B. Restoration of isotonicity by urea diuresis in saltdepleted animals. Two other dogs were first depleted of salt by the standard technique of injecting 5 per cent glucose solution intraperitoneally, 100 ml. per kgm., and withdrawing it after 3 to 4 hours (1). An overnight diuresis was then induced in these animals by means of an intravenous injection, 350 ml. of a 15 per cent solution and 300 ml. of a 10 per cent solution of urea in 5 per cent glucose, respectively. In one of these animals the effects of a subsequent infusion of hypotonic saline, 0.6 per cent, were investigated.In all studies in Groups A and B, movements of water from the extracellular compartment were calculated from changes in the chloride space (4). Alterations in the plasma volume were estimated from changes in the relative blood cell volume and in the hemoglobin concentration of arterial blood (1). Changes in the volume of cell water were obtained by subtracting the increments or decrements of extracellular water from the changes in total body water. These later values were calculated from the changes in body weight; in the periods lasting ?0 hours the weight change was corrected for water of oxidation according to the metabolic mixture (4). The possibility of transfers of sodium and potassium between extracellular an...

Studies in Diabetic Acidosis and Coma, With Particular Emphasis on the Retention of Administered Potassium

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Transfers of Potassium in Renal Insufficiency 1

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Transfers of Cell Sodium and Potassium in Experimental and Clinical Conditions 1

“…Certainly from the standpoint of shifts of water, a change in the osmotic, activity of cell components is often the most important determinant of the ultimate distribution of water between the phases of body fluid. The most striking example of this fact is present in dog 115 (20) in which at 2.7 hours all of the 1.1 liter of water given as 5 per cent glucose solution was retained in the extracellular phase plus an additional 0.1 liter transferred from the intracellular phase. Short of a very large and unlikely water gradient persisting between the 2 phases, this peculiar distribution of water can only be explained by the inactivation of a large amount of cell base, or by a complete failure of glucose to diffuse across the cell membrane.…”

“…The experimental data used in these analyses have been reported previously in a series of papers (16 to 20). Body fluids were altered as follows:…”