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HERMAN O. MOSENTHAL 



the balance of these figures with the intake has a very limited application. 

 This has been taken up under nitrogen balance. If such studies are de- 

 sired it is necessary to measure the quantities ingested and much labor is 

 added to carrying out the test day for renal function. If the patient's 

 routine dietary is followed during this procedure a distinct amount of in- 

 formation can be gained as to the adequacy of the food in any given case. 

 An example of such an interpretation is given in Table 28, in which it 

 is shown that the subject is drinking too little water and eating too small 

 an amount of proteins to maintain life. An instance of overindulgence 

 in food is given in Table 33. 



TABLE 33 



TEST DAY FOB RENAL, FUNCTION WHILE THE PATIENT is TAKING His CUSTOMARY DIET. 

 THE FLUID INTAKE is Too Low (HIGH FIXED SPECIFIC GRAVITY) ; THE AMOUNT OP 

 STARCHES AND PROTEINS EATEN ARE EXCESSIVE (HIGH BLOOD SUGAR, LARGE UREA 

 OUTPUT) 



P. J. Age 56, Blood Pressure 146/48, Weight 215 Ibs. 



Blood Sugar .16 per cent; Urea N 11.9 mg., Uric Acid 2.8 mg., and 



creatinin 2.9 mg. per 100 c.c. 



Urine No albumin, no sugar, microscopic examination negative. 

 Diagnosis Obesity. 

 Renal Function Normal. 

 Metabolism Too little fluid, excessive starch and protein intake. 



In judging of the improper metabolism of patients while the test day for 

 renal function is carried out the chemical blood determinations are indis- 

 pensable as may be gathered from Tables 28 and 33. By these means it 

 may be determined whether a low output is due to insufficient kidney action 

 or to a faulty diet. The carbohydrate metabolism may also be investi- 

 gated in this way to a limited extent as shown in Table 33. 



A summary of the criteria of value and their interpretation when the 

 test day for renal function is carried out while the patient is taking his 

 routine diet, is as follows: (Mosenthal(e), 1920) 



