TRANSFUSION OF BLOOD 823 



HI. Beneficial Effects of Transfusion 



Whatever the purpose for which transfusion may be done, there are 

 various beneficial results to be obtained by the procedure which may be 

 enumerated before a discussion of them is undertaken. They are as 

 follows: 1. The effect upon the oxygen capacity of the blood. 2. The 

 effect upon the blood volume. 3. The effect upon the factors of coagula- 

 tion. 4. The effect upon blood regeneration. 5. The effect upon immune 

 bodies. 6. The effect upon the basal and nitrogen metabolism. 7. The 

 effect upon the more immediate symptomatology. 



1. The Effect upon the Oxygen Capacity of the Blood. One of the 

 chief objects of transfusion is to increase the power of the recipient's blood 

 to carry oxygen. In normal blood the total oxygen capacity which depends 

 upon the hemoglobin content of the corpuscles is about 18.5 volumes per 

 cent. After acute hemorrhage or in severe anemia this figure may be 

 reduced to one-fourth or one-fifth of the normal, and in such conditions 

 it is obvious that more hemoglobin must be introduced into the circulation 

 in order to avoid oxygen starvation of the tissues. This can be done only 

 by giving red corpuscles for which there is no known substitute. 



In the resting normal individual the venous blood returns to the heart 

 with a reserve oxygen supply of 12 to 14 volumes per cent. In a slate of 

 grave anemia, however, as Lundsgaard(e) has pointed out, the tissues may 

 demand the last residuum of available oxygen from the blood, just as 

 readily as the first part, and the blood may return to the heart in a 

 nearly completely asphyxiated state. At the present time there are no 

 figures showing complete asphyxiation of venous blood in man, but the 

 blood of many cases of severe anemia closely approximates this condition, 

 Pfliiger and Voit also showed that the demand of the tissues for oxygen 

 was independent of the supply. The reduction of the oxygen combining 

 power of the blood may be so great in extent that the ordinary compensa- 

 tory factors may not be sufficient to maintain the internal respiration 

 of the body even in a completely resting individual. A condition of this 

 nature is perhaps most often seen in pernicious anemia in which the 

 occurrence of great prostration and tissue changes of serious extent form a 

 familiar clinical picture. What may be immediately accomplished in 

 such a patient is illustrated in Table I, in which is presented the data 

 of a case before and after transfusion of 600 c.c. of blood, together with 

 the oxygen figures for the blood of a normal individual for compari- 

 son. 



In contrast to a normal oxygen reserve of 12 to 14 volumes per cent, 

 this patient had less than two volumes per cent which accounts for his 

 complete physical disability. The longer an individual remains in such a 

 condition the greater the irreparable damage to body structure. Thus if 



