POTASSIUM DEFICIENCY AND THE ROLE OF THE KIDNEY IN ITS PRODUCTION 12

Abstract

Potassium was admd. in daily doses of 0.7 to 3.7 m.eq. per kg. to 6 adult patients maintained on parenteral fluids. Three normal subjects on isocaloric diets were given 4.4, 3.2, and 0 m.eq. of K per kg., as controls. The daily exchanges of electrolytes and N were measured. In 4 of the patients the concns. of K in serum were abnormally low. All of the patients retained admd. K in the cellular phase in excess of N in amts. varying from 1.2 to 4.6 m.eq. /kg. Only one patient received K long enough to show that a maximum degree of retention had been reached. Each of the normal subjects who received K retained only 0.1 m.eq. /kg; During periods of low K intake more K was lost in urine than in gastro-intestinal fluid. In 4 patients during such periods the quantity in urine was greater than was the quantity during periods when the intakes were high and concns. in serum were normal. The minimum amts. in urine in three of the patients deprived of exogenous K and maintained in N equilibrium, were 28, 27 and 6 m.eq. per day, and in the normal subject 34 m.eq. per day. There were no definite symptoms or physical signs attributable to deficiency of K. Cellular deficit of K was noted in the presence of a normal or elevated concn. of serum K. Admn. of K under the latter circumstances may result in cardiotoxic effects. The chief requisites for the development of deficit of K were low intake of the ion and normal renal function. The patients described in this study appear to typify a large group of hospitalized patients sustained on parenteral fluids low in K.