Renal Excretion of Sodium During Hypernatremia

Abstract

Infants with hypernatremic dehydration are sometimes oliguric and as part of the physiologic disturbances of the hypernatremic state, the excretion of a urine with a concentration of sodium in excess of the plasma is not possible. Return to physiologic status requires the addition of water. These observations suggest that there may be impairment of renal ability to excrete sodium. The studies reported herein were undertaken in part to examine the effects of severe experimental hypernatremia upon renal morphology and function. Details of the resultant histologic changes have been reported separately.¹Results of renal function studies and discussion of their possible significance are presented here. Methods Extracorporeal dialysis for five or more hours with a twin coil Kolff "artificial kidney" was used to create hypernatremia in dogs with functioning intact kidneys. This technique permits study of renal response during periods of constant extracellular electrolyte concentrations with no possibility of even