374 



HERMAN O. MOSENTHAL 



TABLE 30 



TEST DAY FOR RENAL FUNCTION IN A PATIENT SUFFERING WITH CARDIAC DECOMPENSA- 

 TION*. NOTE THE HIGH FIXED SPECIFIC GRAVITY, THE GOOD CONCENTRATION OF NI- 

 TROGEN AS COMPARED TO THE Low FIGURES FOR SALT. SOMEWHAT SIMILAR RESULTS 

 MAY BE OBTAINED IN SOME CASES OF NEPHRITIS COMPLICATED BY EDEMA. (Mosen- 

 thal, 1915) 



There are many extrarenal factors and disturbances of the urinary 

 tract besides Bright's disease (see Table 29) that may l)e responsible for 

 a diminished ability of the kidney to concentrate the urine. However, 

 if renal function is to be measured by the quantity and the quality of urine 

 eliminated at the urethra, these facts must be considered. Such diseases 

 and conditions are cystitis, pyelitis, anemia (see Christian for special 

 work on this subject), hypertrophied prostate, urethral stricture, polycystic 

 kidney, elimination of edema, diabetes insipidus, paralysis of the bladder, 

 as in tabes, and others. It becomes clear that clinical judgment must 

 be applied to this as well as other tests for renal function if they are to 

 lie properly valued. In Table 31 the sudden changes that may occur as the 

 result of extrarenal factors that control the formation of edema in ne- 

 phritis are shown. Within less than an hour apparently the condition 

 of oliguria and high specific gravity, which had persisted for several 

 months, changed to one of polyuria and low specific gravity which con- 

 tinued on the succeeding days. 



The maximal specific gravity attained in any specimen of urine on 

 the test day for renal function, if the power of the kidney to concentrate 

 is normal, is 1.020 or higher. The causes for the diminution in the specific 

 gravity have already been mentioned in the preceding paragraphs under 

 the heading of degrees of variation of the specific gravity, and need not 

 be repeated here. 



Nocturnal Polyuria. One of the earliest signs of renal insufficiency 

 is a nocturnal polyuria or nycturia (Quincke(a), v. Leube, Runeberg(a), 

 Wilson, Iljisch, Laspeyeres, Pehu). If a normal person takes no food or 



