Study to Reveal if Fibrinogen Treatment Effects Blood Clotting Better Than a Platelet Transfusion

Patient with the need of a platelet transfusion, will have 4 intervention points. 1. directly before the start of the transfusion a blood sample will be drawn. 2. Patient receives the platelet transfusion. 3. One hour after the end of transfusion a second blood sample will be drawn. 4. 24 h after the end of the platelet transfusion a further bloos sample will be collected. The first two samples will be (beside blood cell counts) spiked in-vitro with different amounts of Human fibrinogen and blood clotting tests will be performed. The same with the 3. blood sample, but without spiking steps.