Sanne de Bruin

13 General Introduction and scope of the thesis transfusions and less organ damage 31 . Hence, further research in personalized trans- fusion protocols is warranted. Treatment of coagulopathy in ICU patients is even more complex. Coagulopathy is treated in order to stop or to prevent a bleeding. Treatment can include administration of specific coagulation factors, plasma transfusions and platelet transfusions. Opti- mal transfusion triggers to prevent or treat coagulopathy remain unclear. Especially transfusion of plasma and platelets in patients with coagulopathy in the absence of a bleeding or an upcoming procedure is controversial 32 . Several studies showed that more than 50%of the plasma transfusions did not result in an International Normalized Ratio (INR) <1.5 32,33 and evidence supporting the benefit of plasma transfusion on (post) procedural bleedings is lacking 34,35 . In addition, in adult patients with a spontaneous cerebral haemorrhage and in neonates, a more liberal platelet transfusion strategy was even associated with an increased mortality 36,37 . Even though these are completely different patient populations, these studies suggest that platelet transfusions might have potential harmful effects. Current transfusion strategies for coagulation disorders are platelet count, PT and aPTT guided. Alternatively, the coagulation state of the blood of a particular patient can be evaluated using viscoelastic tests in which the transition from liquid to a gel state is measured. Themost widely used techniques are rotational thromboelastometry (ROTEM) and thromboelastography (TEG). These techniques were initially only used in the operating room to guide transfusion strategy, but use of these techniques are also studied in the emergency room and on the ICU in the past years 38,39 . Quality of blood components Several factors are associated with an impaired quality of blood components including donor characteristics and storage time. To mitigate donor related risks several mea- sures are taken such as solvent/detergent treatment of pooled plasma to inactivate lipid-enveloped pathogens. Also, transfusion of plasma, pooled male- only plasma is used to minimize the amount human leukocyte antigen (HLA) and human neutrophil antigen (HNA) antibodies that women more often develop due to their ability of being pregnant. To reduce HLA and HNA antibody exposure after platelet transfusion either plasma from male donors or female plasma negative for HLA antibodies is used, or platelets are stored in a mixture of additive solution and plasma. The changes RBCs and platelets undergo during storage are collectively called the stor- age lesion. Several changes are part of the storage lesion, including morphological, 1