RENAL EFFICIENCY AND BLOOD-PRESSURE 169 



Case 4 the observation was vitiated by the urea being given some minutes before 

 the blood sample was taken, while Case 8 was a terminal one dying from aortic 

 heart disease. In Case 7 the vasodilator drug was pushed to the point of intoler- 

 ance (vomiting, &c., being induced) as the blood-pressure was affected with 

 difficulty. This case received liquor trinitrini CWij three-hourly for two days, 

 followed by CCf'ii] three-hourly for one day. It may be noted that in Case 8, during 

 the period of comparatively slight lowering of systolic pressure under the influence 

 of trinitrinum, the general condition was obviously improved, the patient much 

 more comfortable, the pulse slower, and the Cheyne-Stokes' respiration abolished 

 — to recur on the day following the discontinuance of the vasodilator drug when 

 the pressure had again risen. 



2. Effect on the power of the kidney to concentrate urea. All the cases, with 

 one exception, showed no impairment of the power to concenti*ate urea. This 

 Case — 14 — showed a 66 per cent, rise in the first hour in the total amount of 

 urine excreted. With regard to the other cases, the power of the kidney to 

 concentrate urea was increased commonly 25 per cent, up to 75 per cent, above 

 the original value. 



3. Effect on the total quantity of the urine excreted during the three hours 

 following the administration of 15 grm. urea. The majority of the cases showed 

 a decrease in the total amount of urine excreted in the three hours. The percen- 

 tage decrease amounted in many cases to 20-40 per cent., with one case showing 

 a reduction of over 50 per cent. Notable exceptions to the decrease were Cases 7, 



11, and 12 — the last two being recent cases of acute nephritis. Cases 11 (acute 

 nephritis of five days' duration) and 7 showed a 40 per cent, increase in the 

 amount of urine. The increased amount was observed principally during the 

 first hour (Cases 11, 12, 14), and during the first and second hours (Case 7). 



4. Effect on the total urea excreted during the three hours' urea test. The 

 majority of the cases showed little or no substantial change. No case showed 

 any marked cutting down of the total amount. On the other hand, Cases 7, 11, 



12, 18 showed percentage increases of from 35 to 80. The increase in each case 

 was associated with an increase in the total amount of urin6. Two cases 

 (4, 20) showed an increased excretion of urea with a decrease in the total amount 

 of urine. 



5. The relation of the increase in the urea concentration to the fall in blood- 

 pressure is brought out in the following table : 



