SCIENTIFIC PROCEEDINGS 



Abstracts of Communications. 

 Ninety-first meeting. 



University and Bellevue Hospital Medical College, April if, iqi8. 

 President Gies in the chair. 



165 (1343) 



The urea content of the blood. 



By Ludwig Kast and Emma L. Wardell. 



[From the Department of Medicine and the Laboratory of Patho- 

 logical Chemistry, New York Post-Graduate Medical School 

 and Hospital.] 



Although the retention of urea nitrogen in the blood is now 

 generally regarded as a reliable diagnostic sign of faulty kidney 

 function, there still remains a disturbing degree of confusion as 

 to what should be considered the normal and what a pathological 

 urea content of the blood. Repeated observations of Folin and 

 Denis, and those of our own laboratory, seem to prove conclusively 

 that in normal adults the concentration of urea nitrogen is from 

 12 to 15 mg. per 100 c.c. of blood. A study of the records of 

 routine blood analyses of hospital patients, on the other hand, 

 shows that many individuals without symptoms of kidney lesion 

 have a urea nitrogen of more than 15 mg. per 100 c.c. of blood. 

 Of a series of 244 cases, extending over a period of 5 months, 206, 

 or 84 per cent., had a urea nitrogen concentration of not more 

 than 20 mg. per 100 c.c. Of these 206 cases, 83, or 40 per cent., 

 showed some indications of kidney lesion, while of the remaining 

 38 cases in which the urea nitrogen was more than 20 mg., 29, or 

 76 per cent., showed other renal symptoms. Throughout the 

 series the higher blood urea was closely paralleled by the greater 

 degree of kidney lesion, as indicated by presence of casts or albumin 

 in the urine, high blood pressure, high blood sugar and creatinine 



