Disturbances in Blood Coagulation and Thrombocyte Functions after Combined Injuries with Radiation and Trauma,
LABORATORIUM FUER EXPERIMENTELLE RADIOLOGIE NEUHERBERG/MUNICH (GERMANY F R)
Pagination or Media Count:
Besides the plasma coagulation factors, undisturbed hemostasis is dependent on thrombocytes and their normal functions. Dienstbier et al. observed a primary thrombocyte function disability after whole-body irradiation, and Hohage et al. described a reduced platelet aggregation with collagen after whole-body irradiation of rats with 7.0 gray. Platelet number is diminished by radiation, a further reduction of the thrombocyte adhesion and aggregation would increase significantly the risk of acute bleeding. Correspondingly, we analyzed changes in thrombocyte functions after sublethal radiation or surgical trauma alone and their combination as a model of combined injuries. A prolongation of the activated partial thromboplastin time was found after radiation alone, although the fibrinogen concentration, the substrate of the coagulation cascade, was increased as well. We were able to demonstrate a significant decrease in the lag time 24 hours after irradiation, showing the activation of platelets that may lead to a DIC syndrome. In addition, the aggregation time reflecting the speed of the platelet aggregation is decreased after 2 hours, but significantly increased after 24 hours following combined injuries.