Thromboelastogram & ROTEM

Description

Initially described in 1948 by Hertert thromboelastography (TEG) provides a real-time assessment of viscoelastic clot strength in whole blood. Rotational thromboelastometry (ROTEM) evolved from TEG technology and both devices generate output by transducing changes in the viscoelastic strength of a small sample of clotting blood (300 ml) to which a constant rotational force is applied. These point of care devices allow visual assessment of blood coagulation from clot formation, through propagation, and stabilization, until clot dissolution. Computer analysis of the output allows sophisticated clot formation/dissolution kinetics and clot strength data to be generated. Activation of clot formation can be initiated with both intrinsic (kaolin, ellagic acid) and extrinsic (tissue factor) activators. In addition, the independent contributions of platelets and fibrinogen to final clot strength can be assessed using added platelet inhibitors (abciximab and cytochalasin D). Preoperative anticoagulation or perioperative coagulopathy secondary to trauma, massive transfusion, sepsis, cardiopulmonary bypass (CPB) or hypothermia may impair haemostasis. Under such circumstances, the result of this coagulation tests could reduce inappropriate blood product administration by correct targeting of specific coagulation deficiencies. In this presentation , we deal with ROTEM , TEG and platelet function analysers.