Clinical and Experimental Studies on the Changes of Platelets Following Massive Transfusions of Preserved Blood Part Ⅰ. Changes in Bleeding Time, Coagulation Time and Platelets Following Massive Transfusions of Preserved Blood

Changes in platelets, bleeding time and clotting time following massive transfusions of preserved blood were studied, experimentally and clinically. Hemorrhagic tendencies were observed in three of clinical cases and also in experimental cases. Striking descrease in number of platelets were observed in every case shown hemorrhagic tendency, and was considered as its main factor. And hemorrhagic tendency was appeared before the occurrence of prolongation in bleeding time, though, changes in clotting time was not so significant. Decrease in number of platelets was not specific to the massive transfusions of preserved blood, and was also observed in the cases transfused saline solution, red cell suspension, hemolized blood, massive fresh blood or plasma. It was surmised that the hemorrhagic tendency was preduced by intervention of vascular factor in addition to the decrease in number of platelets.