Use of Viscoelastography in Malignancy-Associated Coagulopathy and Thrombosis: A Review.

The relationship between malignancy and coagulopathy is one that is well documented yet incompletely understood. Clinicians have attempted to quantify the hypercoagulable state produced in various malignancies using common coagulation tests such as prothrombin time, activated partial thromboplastin time, and platelet count; however, due to these tests' focus on individual aspects of coagulation during one specific time point, they have failed to provide clinicians the complete picture of malignancy-associated coagulopathy (MAC). Viscoelastic tests (VETs), such as thromboelastography (TEG) and rotational thromboelastometry (ROTEM), are whole blood analyses that have the advantage of providing information related to the cumulative effects of plasma clotting factors, platelets, leukocytes, and red cells during all stages of the coagulation and fibrinolytic processes. VETs have gained popularity in the care of trauma patients to objectively measure trauma-induced coagulopathy (TIC), but the utility of VETs remains yet unrealized in many other medical specialties. The authors discuss the similarities and differences between TIC and MAC, and propose a mechanism for the hypercoagulable state of MAC that revolves around the thrombomodulin-thrombin complex as it switches between activating the protein C anticoagulation pathway or the thrombin activatable fibrinolysis inhibitor coagulation pathway. Additionally, they review the current literature on the use of TEG and ROTEM in patients with various malignancies. Although limited research is currently available, early results demonstrate the utility of both TEG and ROTEM in the prediction of hypercoagulable states and thromboembolic complications in oncologic patients.

Fibrinolysis in Trauma: "Myth," "Reality," or "Something in Between".

The emphasis on fibrinolysis as an important contributor to trauma-induced coagulopathy (TIC) has led to a debate regarding the relative clinical significance of fibrinolysis in the setting of trauma. The debate has centered on two camps. The one camp defines fibrinolysis in trauma by standard coagulation tests as well as fibrin split products, D-dimers, and plasmin/antiplasmin levels. This camp favors a more liberal use of tranexamic acid and attributes more significance to hyperfibrinolysis in TIC. The other camp favors a definition of fibrinolysis based on the viscoelastic tests (VET), rotational thromboelastometry (ROTEM), and thromboelastography (TEG). These whole blood assays define hyperfibrinolysis at a higher threshold than plasma-based tests. Therefore, this VET camp reserves antifibrinolytic treatment for patients who demonstrate severe coagulopathy associated with hyperfibrinolysis. This bimodal attribution of the clinical relevance of fibrinolysis in trauma suggests that there may be an underlying "Myth" of the concept of TIC that was historically defined by plasma-based tests and a future "Reality" of the concept of TIC that is grounded on an understanding of TIC based on a VET-defined "fibrinolytic spectrum" of TIC. This narrative review explores this "Myth" and "Reality" of fibrinolysis in TIC and proposes a direction that will allow a "Future" interpretation of TIC that incorporates both the past "Myth" and present "Reality" of fibrinolysis TIC.

Tranexamic Acid for Trauma Resuscitation in the United States of America.

The utilization of tranexamic acid (TXA) for the management of bleeding trauma patients has been a subject of much debate on both sides of the Atlantic and in Australia. As a result of the large randomized controlled study called the Clinical Randomization of an Antifibrinolytic in Severe Hemorrhage (CRASH-2), there was an initial enthusiasm for the use of TXA to treat bleeding patients. However, the adoption of TXA in the United States was delayed by concerns of "knowledge and evidence gaps" of the CRASH-2 study and because of a lack of mechanistic rationale that would explain the survival benefit noted in the study. Subsequent nonrandomized controlled trials questioned the liberal use of TXA in trauma patients. This narrative review explores the historical as well as clinical and theoretical grounds for the more measured use of TXA in the United States and proposes a clinical and point-of-care guided utilization of TXA, blood components, and adjunctive hemostatic agents in bleeding trauma patients.