Water and Electrolytes in Congestive Failure 275 



Farber and co-workers (1951, 1953) studied in man the 

 effect of an increase of pressure in the vena cava produced by 

 means of a balloon above and below the orifice of the renal 

 veins. In both procedures there was a diminution of renal 

 blood flow, glomerular filtration rate and excretion of water 

 and electrolytes. 



The increased central venous pressure in congestive failure 

 may, of course, contribute to reduction in renal function 

 (Briggs et al., 1948; Bradley and Blake, 1949; Earle et ah, 

 1949). It determines the distribution of retained water and 

 electrolytes, which in left-sided failure is in the lungs and in 

 congestive failure mainly in the lower part of the body. 



The nature of renal changes in congestive failure. 



The nocturnal increase of diuresis and renal blood flow in 

 our investigated patients with congestive failure was also 

 associated with an elevation of glomerular filtration rate and 

 with a decrease in tubular reabsorption of water and electro- 

 lytes. This may be seen in Fig. 3, which covers 20 spon- 

 taneous changes in urine flow in 14 patients with congestive 

 failure. The lower urine output was always taken as the 

 initial value (100 per cent). 



The mean increase in diuresis was 187 per cent (range from 

 44 to 672 percent). This increase was associated in all instances 

 (as seen in Fig. 1) with an elevation in renal blood flow. This 

 latter increased on the average by 55-5 per cent (from 6 to 

 146 per cent). Only three times was the increase in renal 

 blood flow smaller than 20 per cent. In 14 subjects in whom it 

 was measured cardiac output (CO) rose significantly in six 

 instances, fell in three and did not change in five. It is clear 

 that the increase in renal blood flow could not depend on the 

 primary increase in CO. This is confirmed by an increase in 

 the renal fraction of cardiac output in all instances except 

 one, in which the renal fraction did not change. 



Glomerular filtration rate at high urine flow was elevated 

 15 times, and unchanged five times. The average increase 

 was 27 • 1 per cent, with the range — 4 • 5 to + 82 per cent. 



