THE METABOLISM OF TRAUMATIC SHOCK 259 



nitrogen of the blood, and concluded that there was an increase in the 

 non-protein nitrogen which started promptly after the wounding, and 

 was at its height during the second day, and then gradually returned to 

 normal. This increase was slight in unshocked cases but was striking 

 in cases of shock. This retention occurred, not only in the urea portion 

 of the blood, as in nephritis, but also in the remainder of the non-protein 

 nitrogen. Aub and Wu likewise demonstrated a marked increase in the 

 non-protein nitrogen of the blood in experimental shock, and found that 

 the creatin portion of the non-protein nitrogen was increased in far greater 

 proportion than was urea or the total non-protein nitrogen. This change 

 in the non-protein nitrogen of the blood appeared only when shock de- 

 veloped. In control experiments where blood pressure and blood flow were 

 reduced by increasing the pericardial pressure, the values for non-protein 

 nitrogen and creatin were not markedly changed. In the experiments 

 where muscle trauma was inflicted but no shock developed, there was like- 

 wise but slight change in the non-protein nitrogen. When shock de- 

 veloped, however, the amount of non-protein nitrogen in the blood rose 

 markedly, and the values for the creatin were sometimes three times as 

 high as before trauma had been inflicted. This marked rise in creatin 

 was taken as direct evidence of the presence in the blood of products of 

 muscle necrosis, and was, therefore, considered suggestive evidence for 

 the theory of a chemical cause of traumatic shock. 



The blood sugar is likewise increased in shock. This was first noticed 

 by Cannon in wounded soldiers who were in shocked condition ; it was also 

 observed by Aub and Wu in experimental traumatic shock in animals, 

 where it occurred to a much greater extent than was present in man. 

 It is difficult to explain this rise in blood sugar. 



Very little work has been done on the urine in shock, probably because 

 of the acute onset of the condition and the difficulty of getting satisfactory 

 specimens. Mestrezat, working on a few cases, did a nitrogen partition 

 of the urine, and found that the rest nitrogen, other than urea, was in 

 much greater proportion to the total nitrogen than usual. This is in 

 agreement with the changes described in the non-protein nitrogen of the 

 blood. 



Summary 



From the evidence cited above it seems that the sequence of events in 

 traumatic shock is as follows : There is first a slowing of the blood flow, 

 probably accompanying a decrease in blood volume. This decreased blood 

 volume and blood flow as they progress become so great that vasoconstric- 

 tion can no longer maintain a normal blood pressure. The blood pressure 

 then falls, and a condition of anoxemia or inadequate oxygen supply is 

 present in the tissues. With this anoxemia, there develops a diminished 



