PATHOLOGICAL METABOLISM OF THE BLOOD 595 



animals. The heightened metabolism noted by both observers has been 

 attributed to the agitation and dyspnea attendant on the operation rather 

 than to the direct effects of transfusion itself. 



Tompkins, Brittingham, and Drinker, on the contrary, found that 

 transfusion in clinical cases of anemia, and more especially in per- 

 nicious anemia, usually lowers the basal metabolism, which may reach 

 a normal or a diminished level depending upon the rate before trans- 

 fusion. The factors underlying this fall in the metabolic rate are not 

 well understood. Those who are inclined to attribute the heightened 

 metabolism so frequently observed in anemia to the increased muscular 

 work required by the more rapid respiration and heart rate, maintain 

 that transfusion lowers the calorific output by diminishing the pulse and 

 respiratory activity. That restraint of the muscular compensations, how- 

 ever, is not the only cause of the lowered metabolism follows from the 

 experiments of Drinker and his associates. They found, for instance, 

 that, although transfusion produces an almost immediate check to the 

 accelerated heart and lung action, the maximum effect on the metabolism 

 takes place only after several days. Such an observation would seem to 

 suggest that transfusion produces its effect not alone by influencing 

 the compensatory muscular activity but also by modifying, in some way, 

 certain other factors which exert an influence on the metabolism of the 

 anemic individual. 



The influence of transfusion on the nitrogenous metabolism has been 

 studied experimentally by Haskins(a) and in man by Crile(a). In two 

 experiments on dogs, extending over an average period of two days before 

 and two days after operation, Haskins observed that transfusion fol- 

 lowing hemorrhage produced a greater rise in the percentage output of 

 total nitrogen, ammonia nitrogen, uric acid and creatinin than a mod- 

 erate hemorrhage alone. A comparison of the figures obtained in one 

 of the animals after a moderate hemorrhage followed by a transfusion 

 of approximately the same quantity of blood is of interest: the total 

 nitrogen, ammonia nitrogen, and uric acid increased 14.7 per cent, 11 per 

 cent and 14 per cent respectively after hemorrhage as compared with 

 20 per cent, 15 per cent, and 18 per cent respectively after transfusion. 

 The creatinin, however, decreased 7.8 per cent after hemorrhage, but 

 increased 3.7 per cent after transfusion; whereas the percentage of urea 

 nitrogen fell in both instances, but slightly more so after hemorrhage 

 alone. 



A similar rise in the excretion of nitrogen, and ammonia after trans- 

 fusion has been observed clinically by Crile in one patient. In this in- 

 stance, the nitrogen after transfusion rose from 10.3 grams to 16.5 grams 

 in the twenty-four-hour period, and the ammonia increased from 0.16 

 gram to 0.47 gram. Both of these constituents returned to practically 

 the original level by the fifth day after the transfusion. 



