i9ii] Reuben Ottenberg 319 



V. THE BLOOD AS A FACTOR IN EDEMA 



Reuben Ottenberg 



One of the earliest observations was that of hydremia in ne- 

 phritis. But later work (by Senator and many others) showed that 

 the hydremia instead of being the cause of the nephritis (as was at 

 first thought), is the sequel of it. In typical edema of chronic 

 nephritis, hydremia only appears after the edema is well established, 

 and is not in any regulär proportion to the degree of edema. Fur- 

 thermore extreme grades of hydremia occur in other diseases 

 (anemia, cachexia), without edema. 



One of the most remarkable things about the blood is its great 

 tendency to retain a constant composition. Loeb has shown the 

 importance of constant composition of the surrounding medium for 

 the lower organisms. For the more delicate adjustments of the 

 higher organisms a still greater constancy in the composition of 

 the fluids which connect the cells seems to be necessary. Injections 

 of all sorts of substances — water, salts, proteins, into the circula- 

 tion, are followed by prompt removal of the substances from the 

 circulation, either by excretion in the kidney, or by absorption in 

 the tissues. 



The theories which connect certain types of edema with salt 

 retention are in agreement with this knowledge. The old empirical 

 Observation of the therapeutic value of the milk diet led Widal, 

 Strauss, and others to investigate the peculiarity in this diet which 

 gave the good results. They found that it was the low salt 

 content; that by addition of salt to the milk it could be robbed 

 of its virtues, and conversely that other forms of salt-poor food 

 gave equally good, and sometimes better results. Widal divides 

 nephritis into two types — the type with diminished power of sodium 

 Chloride excretion, and consequent tendency to edema, and the type 

 with diminished power of excretion of the products of nitrogen 

 metabolism and the tendency to uremia. In the former type the 

 value of the salt-poor diet has becn confirmed by many observers. 

 Others have shown that not only Chlorides, but also other salts, such 

 as phosphates and carbonates, are of importance. Widal also made 

 the important observations that the appearance of external edema is 



