Quantitative Study of Effect of Transfusion of Blood on Plasma Prothrombin. ∗

It is established that the bleeding tendency in obstructive jaundice and biliary fistula is due to a lowering of the plasma prothrombin. Both on clinical 1 and experimental 2 grounds, blood transfusion is known to effect temporary improvement in the hemorrhagic state. Warner, Brinkhous and Smith 2 have shown in dogs with a biliary fistula of long duration that after a blood transfusion there is a temporary rise in plasma prothrombin with a cessation of bleeding.

The purpose of this report is to demonstrate in dogs that it is possible to determine quantitatively the prothrombin change which occurs following transfusion and that the change is purely one of summation.

The animals used as recipients were of 3 types: 2 animals were normal dogs, 2 were dogs with obstructive jaundice, and one was a dog with a cholecyst-nephrostomy. 3 Normal dogs were used as donor animals. Plasma volumes before transfusion were determined by the vital red method. 4 The plasma volume after transfusion was calculated by addition of the volume of transfused plasma to the pretransfusion value. Prothrombin units before and 3 hours after the transfusion were determined by the method of Warner, Brinkhous and Smith. 5 All transfusions were performed by the indirect method, using sodium citrate as the anticoagulant.

The experiments in Table I show the effect of transfusions of citrated blood. Within the limits of experimental error, the actual total prothrombin content of the plasma of the recipient determined three hours after transfusion corresponds closely with the expected total. The error varies from plus 6.3% to minus 8.4% with an average of minus 1.3%. This indicates that the prothrombin in the plasma of the donor is distributed throughout the plasma of the recipient and can be detected quantitatively in the latter 3 hours after the transfusion. It further indicates that the change following transfusion is simply one of summation.