Abstract
The question of the effect on blood coagulation of the injection of sodium citrate into the circulation was raised immediately after the introduction of the citrate method of obtaining blood for transfusion.
Weil found that in cases with normal coagulation, the coagulation time immediately after citrate transfusions was slightly shortened instead of lengthened. As the question is one of particular importance in the hemorrhagic diseases and as there have been no observations recorded on the ultimate effect of citrate administration on the coagulation of blood, I wish to present some experiments in a case of hemophilia, whose prolonged coagulation time made it particularly suitable for this study.
The patient, an adult male, had nearly bled to death at least six times and presented all the typical features of the disease excepting the family history. The blood count showed nothing abnormal and the blood platelets were within the normal range or slightly above it (490,000 per cu. mm. counted in metaphosphate solution in a counting chamber). The coagulation time of his blood obtained at various intervals within the preceding three years had always been between one and two and a half hours.
The method of determining the coagulation time consisted in obtaining approximately three cubic centimeters of blood with a hollow needle direct from an arm vein. The blood was received into a clean five cubic centimeter test tube and observed at regular intervals, being kept at approximately body temperature. Complete coagulation was recorded when it was possible to turn the tube up-side down without the blood flowing. Beginging or partial coagulation was noted by the retarded flow of the blood when the tube was slanted. This method is far preferable to all the methods which involve the taking of drops of blood from the finger or ear as these methods, due to the admixture of fluids from subcutaneous tissues, give notoriously inaccurate results.
Get full access to this article
View all access options for this article.