The introduction, by Howard and his group in 1953,1,14 of the relatively simple split-function test formulated, for the first time, a rational approach to the evaluation of hypertension of unilateral renal origin. Since that time, it has become apparent that the original criteria had been inadequate for diagnosis in a number of cases; and, therefore, many modifications have been proposed.2-13 These have undoubtedly added a substantial degree of accuracy of diagnosis; but, unfortunately, they have eliminated the relative simplicity of the test.
In the course of our study of hypertension by means of complete differential renal clearances,11 it became apparent that certain changes in the differential excretion of sodium and water were produced by the infusion of inulin and para-aminohippuric acid (PAH) in 5% dextrose and water. A method, therefore, may now be available for combining the better features of both types of tests; i.e., simplicity and
MADELOFF MS, SCHWARTZ FD, BORGES FJ, REVELL STR, YOUNG JD. The Differential Excretion of Sodium and Water in Man. Arch Surg. 1962;85(6):994-998. doi:10.1001/archsurg.1962.01310060130022