Super TEG : Beyond the ordinary ‐ Rapid TEG , ROTEM , Platelet Mapping

Learning Objectives: 1. Understand mechanism of Rapid TEG, Platelet Mapping and ROTEM as compared to classic Thromboelastography 2. Understand applications of Platelet mapping in the clinical setting 3. Describe clinical application and evidence for using Rapid TEG 4. Discuss how these modified POC tests fit into current transfusion models Introduction: This syllabus will attempt to provide the background information needed to discuss the newer modalities used in thromboelastography. The lecture will focus on clinical utility of these tests, while the syllabus will attempt to fill in the key details. A basic understanding of platelet function and physiology is important in order to evaluate the effectiveness of the various Point of Care (POC) tests available on the market today. Given the complexities of the coagulation system, there are numerous methods available to test coagulation in the laboratory. The coagulation system as a whole has been thought of historically as the extrinsic (tissue factor) pathway and intrinsic (contact activation) pathway, which is conveniently measured by the prothrombin time (PT) time and activated partial thromboplastin time (aPTT) respectively (Figure 1). The common pathway was thought to represent the intersection point where thrombin is generated to produce widespread clotting. This entire process is now understood to happen in a more cohesive and dynamic process that is interdependent on activation of the various enzymes in the coagulation cascade, along with a synergy of cell signaling and activation that depends in large part on platelet function. The term cell based clotting is now frequently used to describe this process. Briefly, exposure of blood vessel endothelium initiates a cascade of proteolytic reactions that are localized to the platelet surface, allowing association of thrombin and fibrin in close association with activated platelets. Platelet Function in Hemostasis: