372 



HERMAN O. MOSENTHAL 



TABLE 28 



A CASE IN WHICH A HIGH, SOMEWHAT FIXED SPECIFIC GRAVITY is DUE TO AN INADE- 

 QUATE FLUID INTAKE; THE Low CHLORID AND UREA OUTPUT INDICATE THAT THI 

 PATIENT is ON AN INSUFFICIENT DIET FOR THE PROPER MAINTENANCE OF NUTRITION ; 

 THE TEST WAS CARRIED OUT WHILE THE PATIENT WAS TAKING HER CUSTOMARY 

 DIET 



Mrs. E., Age 28, Blood Pressure 126/78. 

 Blood Sugar .10 per cent, Urea N 9.9 mg. per 100 c.c., Uric Acid 2.9 

 mg. per 100 c.c. 



Urine Trace of albumin, a few pus cells, an occasional red blood cell. 



Diagnosis Renal calculus. 



Renal Function Normal. 



Metabolism Fluid, sodium chlorid and protein intake low. 



It is probable that there should be a variation of at least nine points in 

 the specific gravity readings if the kidney is to be permitted to act at its 

 maximal efficiency. In this case, therefore, it is decidedly indicated that 

 more fluid should be taken with the food. 



When the kidney becomes insufficient, one of the first signs to manifest 

 itself is the inability to void a concentrated urine. Any retention which 

 might occur because of this is compensated for by an increase in the urine 

 volume. If the ability to produce a polyuria is practically without limit, 

 there will be no evidences of lack of elimination of the solids. This is 

 very well illustrated in diabetes insipidus. In this disease there is no 

 diminution of renal function, according to any of the tests, except that 

 a polyuria and a very low and fixed specific gravity exist. Even though 

 the phthalein elimination be perfect and there is no accumulation of the 

 waste products in the blood, yet there is loss of one very distinct function of 

 the kidney, that of the power of concentration. Under such circumstances, 

 when one test for renal function does not tally with the remainder, it has 

 been customary, on the part of some investigators, to condemn one or 

 the other of these procedures as being worthless. In the heat of the argu- 

 ment it is often forgotten that tests based on physiological processes must 

 have a definite meaning if the knowledge is at hand to interpret them 



