Differential renal function studies during mannitol diuresis in hypertension.

DIFFERENTIAL renal function studies during water diuresis were introduced by Howard and associates' in 1954 to aid in detection of hypertension secondary to unilateral renal disease. To enhance the diagnostic and prognostic value of such tests, many modifications in the conditions for their performance have been developed: Dustan and co-workers2 studied patients during osmotic diuresis with mannitol. Stamey and associates3 induced diuresis with hypertonic urea in saline. Birchall and associates4 suggested a provocative test with hypertonic saline. Jones and Barraclough5 reported their experience with infusion of angiotensin. Madeloff and associates6 concluded that differences in water and sodium excretion in unilateral renal ischemia were accentuated simply by infusion of inulin and para-aminohippurate (PAH) in dextrose and water. Of all these procedures, the one utilizing mannitol has been subject to the greatest criticism on the grounds that functional differences between the kidneys in renal artery hypertension are obscured.3, 7, 8 The present study was undertaken to determine the value of mannitol diuresis in the investigation of differential renal function in patients with hypertension.