Water and Electrolytes in Congestive Failure 291 



probably not just a consequence of postoperative suppura- 

 tion; it must already have been present before the operation. 



Experiences with two other patients with mitral stenosis 

 and congestive failure, who died within a week after operation 

 with a picture of combined peripheral and cardiac failure, led 

 us to the conclusion that a greater operative risk with mitral 

 commissurotomy in patients with congestive failure (group IV 

 in the usual classification) is associated with potassium 

 depletion and intracellular acidosis with increased retention 

 of sodium (Fejfar et al., 1958a). 



Negative nitrogen balance following surgical operations is 

 connected with potassium depletion (Moore and Ball, 1952), 

 and it is clear that in patients with potassium depletion in 

 chronic congestive failure a further loss of potassium after 

 operation brings about various complications (shock, acute 

 heart failure, infection, slow recovery, etc.). 



It follows that the laboratory diagnosis of potassium 

 depletion in chronic congestive failure is not easy to make. A 

 low serum concentration of Na+, as an indirect indicator, is 

 present only in very advanced stages. One should suspect 

 potassium depletion if there is a decrease of serum chloride 

 and a rise in HCOg" accompanying the usual urinary pattern 

 in heart failure (negligible concentration of Na+ and a marked 

 excretion of K+). 



Analysis of a muscle biopsy specimen or balance studies, 

 which, together with measurement of total exchangeable K+, 

 are at present the only methods for detecting early stages of a 

 metabolic imbalance of electrolytes, are both rather compli- 

 cated for practical use. 



It is therefore more useful to assume potassium depletion 

 in every patient with chronic congestive failure. The treat- 

 ment of every patient should be supplemented by a diet rich 

 in potassium. In more severe cases potassium salts are useful, 

 being particularly important in all patients treated with 

 mercurial diuretics. Cort (1955c) demonstrated in 12 patients 

 with congestive failure that potassium chloride, given some 

 days before the injection of mercury, potentiated its diuretic 



