thromboplastin and Brain-Hemorrhage--Traumatic

Polytraumatic injury results in tissue factor (TF) release from damaged cells. The acute coagulopathy of trauma (ACT) occurs early and results from significant tissue injury and tissue hypoperfusion. ACT is augmented by therapies resulting in acidemia, hypothermia, and hemodilution contributing to trauma-induced coagulopathy. Coagulopathy associated with traumatic brain injury (TBI) results from the interplay of numerous variables. Because of the high concentration of TF in brain tissue, TBI has been believed to be associated with a greater degree of coagulopathy compared with injury in other body systems. TBI has also recently been shown to cause platelet dysfunction. Platelet receptor inhibition prevents cellular initiation and amplification of the clotting cascade, limiting thrombin incorporation, and stabilization of clot to stop hemorrhage. Therefore, head injury in the presence of polytrauma does appear to augment ACT and warrants close monitoring and appropriate intervention.

Topics: Blood Coagulation Disorders; Brain; Brain Hemorrhage, Traumatic; Brain Injuries; Humans; Models, Biological; Multiple Trauma; Signal Transduction; Thromboplastin

Traumatic injury is a common cause of coagulopathy, primarily due to blood loss and hemodilution secondary to fluid resuscitation. Traumatic injury-associated coagulopathy often follows a course of transition from hyper- to hypocoagulable state exemplified in disseminated intravascular coagulation. The incidence of coagulopathy is significantly higher in patients with traumatic brain injury (TBI), especially those with penetrating trauma compared to injury to the trunk and limbs. This occurs despite the fact that patients with isolated TBI bleed less and receive restricted volume load of fluids. TBI-associated coagulopathy is extensively documented to associate with poor clinical outcomes, but its pathophysiology remains poorly understood. Studies in the past have shown that brain tissue is highly enriched in key procoagulant molecules. This review focuses on the biochemical and cellular characteristics of these molecules and pathways that could make brain uniquely procoagulant and prone to coagulopathy. Understanding this unique procoagulant environment will help to identify new therapeutic targets that could reverse a state of coagulopathy with minimal impacts on hemostasis, a critical requirement for neurosurgical treatments of TBI.

Topics: Animals; Blood Coagulation Disorders; Brain Hemorrhage, Traumatic; Brain Injuries; Endothelium, Vascular; Humans; Phosphatidylserines; Phospholipids; Platelet Activating Factor; Platelet Count; Thromboplastin