What is TIC?
Trauma Induced Coagulopathy (TIC) is an acute disturbance in the ability of the body to create clot which occurs after severe traumatic injury. It can result in excessive and ongoing bleeding which can be difficult to stop. It can complicate traumatic injury in up to 25% of patients and is associated with a higher risk of death following traumatic injury. (Sperry)
To date, no consensus statement regarding the clinical presentation of TIC exists. Hence, the investigators of TACTIC propose the following quantitative scoring systems for TIC:
Table 1: Clinical Coagulopathy Score (I-V); to be determined by the attending trauma surgeon after mechanical hemorrhage control is obtained.
|II||Mild coagulopathy, no intervention required except direct pressure or temporary gauze tamponade|
|III||Coagulopathy refractory to direct pressure, requiring advanced hemostasis techniques (e.g., electrocautery, topic hemostatic agents, staples, or suturing)|
|IV||Coagulopathy requiring adjunctive blood component therapy or systemic therapeutics in response to continued bleeding despite above surgical hemostatic maneuvers|
|V||Diffuse persistent bleeding from multiple sites remote from injury; e.g. endotracheal tube, intravenous catheter, chest tubes, etc|
Trauma is a leading cause of death and disability. Hemorrhage (bleeding) is the major mechanism responsible for death during the first 24 hours following trauma. Determining the underlying mechanisms responsible for TIC may lead to better treatments and management options for this excessive bleeding and may improve outcome following traumatic injury.
In 2010, the National Institute of Health (NIH) recognizing the ongoing knowledge gaps in the diagnosis and management of coagulopathy associated with severe injury, organized a workshop and arrived at a consensus to name this phenomenon trauma-induced coagulopathy (TIC). While detailed analyses of laboratory data related to TIC have been correlated with outcomes, there are a spectrum of coagulopathic phenotypes and investigative efforts have been limited either by the lack of 1) a standardized clinical scoring system for coagulopathy, or 2) criteria for determining whether coagulopathy impacted postinjury mortality; i.e. are they dying because they are bleeding or bleeding because they are dying. In recognition of the significance of TIC as a clinical problem, the NIH has funded the Trans-Agency Consortium for Trauma-Induced Coagulopathy (TACTIC) through the National Heart, Lung, and Blood Institute (NHLBI). (Park)
The current resuscitation strategy for severe hemorrhage is a reactive (i.e., transfusion based on signs of clinical deterioration or hemorrhagic shock) rather than a proactive approach due to lack of effective tools for early identification of TIC before the later overt clinical signs (hypotension, anemia) become evident. For example, the decision to implement “damage control resuscitation”, in which exsanguinating trauma patients receive 1:1:1 red cell, platelet and plasma unit ratio transfusions, is still based on clinical judgment. Importantly, damage control resuscitation appears to have limited effect on TIC, and inappropriate transfusions are associated with increased complications (e.g., acute respiratory distress syndrome and increased infections) with no survival benefit.
TACTIC represents a consortium of investigators who have partnered in a collaborative effort between the NIH and the Department of Defense (DOD) to investigate the problem of coagulopathy after trauma, ranging from large scale clinical research studies at multiple sites to basic mechanistic laboratory investigations. Investigators of TACTIC will address critical barriers to progress in improving survival of patients after traumatic injury:
- Mechanisms and extent of thrombin generation in TIC
- Platelet dysfunction after injury
- Dysregulation of fibrinolysis and fibrin clot instability in TIC
- Investigation of novel clinical platforms for assessment of TIC