presence of heparin and represents an INTEM test without interference by heparin or heparin like anticoagulants. The difference between HEPTEM and INTEM CT-value comparison confirms the presence of heparin, e.g. accidental exposure. EXTEM test mildly activates haemostasis via the physiological activator tissue factor. The result is influenced by extrinsic coagulation factors, platelets and fibrinogen. EXTEM is a screening test for the (extrinsic) haemostasis system. This assay is not influenced by heparin (heparin inhibitor included in the EXTEM reagent). It is used for therapeutic decisions regarding the administration of fresh frozen plasma, coagulation factors, fibrinogen or platelets. EXTEM is also the base activator for FIBTEM and APTEM. FIBTEM test is an EXTEM based assay for the fibrin part of the clot. FIBTEM eliminates the platelet contribution of clot formation by inhibiting the platelets irreversibly with cytochalasin D, a potent inhibitor of actin polymerization which disrupts actin microfilaments, an essential part of a cytoskeleton-mediated contractibility apparatus of the platelet. The use of cytochalasin is more favorable than using glycoprotein IIb/ IIIa inhibitors which block platelet incompletely, especially at higher platelet counts. FIBTEM allows for the detection of fibrinogen deficiency or fibrin polymerization disorders, e.g. induced by certain plasma expanders, and may identify rapidly the need to substitute fibrinogen. FIBTEM results correlate well in many cases with the Clauss fibrinogen assay, but is additionally influenced by fibrin polymerization disorders which cannot reliably be detected with clotting tests. APTEM test is an EXTEM based assay in which fibrinolysis is inhibited by aprotinin in the reagent. A significant improvement of the clot in APTEM compared to EXTEM allows to detect fulminant hyperfibrinolysis. Therefore, the test helps in identifying the necessity of administrating antifibrinolytic drugs. Furthermore, APTEM enables the estimation if an antifibrinolytic therapy alone normalizes coagulation or if additional measures have to be taken (e.g. administration of fibrinogen or platelets). Quality control Quality control is an important requirement in laboratory and POC testing. An automatic internal electronic control procedure is implemented in the ROTEM whole blood analyzer. Furthermore, biological control materials at 2 different levels are available and should be used in order to document quality and validity of results. Clinical application TEM is successfully used in the near patient assessment of haemostasis. The method allows detection of complex haemostasis disorders (available in most coagulopathies) within a few minutes and thus enables rapid therapeutic intervention. Whole blood TEM is sensitive to haemostasis affecting agents such