RotationsThromboelastometrie

RotationsThromboelastometrie, commonly referred to as ROTEM, is a viscoelastic hemostasis assay that evaluates the dynamic process of clot formation and dissolution in whole blood. It provides a real-time, graphical representation of coagulation from initiation through stabilization to fibrinolysis, enabling rapid assessment of a patient’s coagulation status.

In ROTEM, a blood sample is placed in a cup and a component (such as a pin or shaft) is rotated or coupled to a sensor. As a clot forms and strengthens, the mechanical resistance changes the signal, producing a thromboelastogram. This allows simultaneous assessment of clot initiation, propagation, stabilization, and breakdown.

Assays used in ROTEM include EXTEM (extrinsic pathway activation with tissue factor), INTEM (intrinsic pathway activation via contact factors), FIBTEM (assessing the fibrin-based clot by inhibiting platelets), and APTEM (to detect fibrinolysis by including an anti-fibrinolytic. These assays help differentiate the contributions of platelets, fibrinogen, and the coagulation cascade.

Key parameters in ROTEM are CT (clotting time), CFT (clot formation time), the α-angle, and MCF (maximum clot firmness). Lysis is assessed with indices such as LI30 or LI60. The results are often presented as a thromboelastogram for each assay, providing a rapid, point-of-care overview of coagulation status.

Clinical use and interpretation: ROTEM is widely used in perioperative settings, major trauma, obstetrics, liver transplantation, and cardiopulmonary bypass to guide transfusion therapy and hemostatic interventions. It supports targeted treatment (platelets, fibrinogen, plasma, antifibrinolytics) and can reduce unnecessary blood product exposure.

Limitations include the need for trained operators, device variability, and the fact that ROTEM complements but does not completely replace conventional coagulation tests.