Evidence from systematic reviews on the use of tranexamic acid in trauma

Abstract

Trauma consists in structural and physiological alterations suffered by the organism due to exposure to one or more forms of energy. In terms of public health, it can be considered a global epidemic disease, with high morbimortality rates. According to data from the World Health Organization (WHO), trauma was responsible for 4.9 million deaths in the world in 2016, of which 70% were men. Traffic accidents account for a quarter of those deaths, followed by homicides and suicides. In Brazil, considering all ages, trauma corresponds to the third cause of death, victimizing mainly men between the ages of 20 and 29, a fact that leads to important socioeconomic impacts. Regarding trauma mortality, head trauma is the main cause of death (45%). The hemorrhage occupies the second position in the causes of death (30%), being the first avoidable cause. As an aggravating factor for hemorrhagic shock, it is worth highlighting trauma-associated coagulopathies, which, if it is not controlled, can lead to death in a short period of time. Its mechanism derives from several synergistic factors, such as hemodilution due to excessive infusion of crystalloids, loss of coagulation factors, hypothermia, acidemia and post-trauma hyperfibrinolysis. This hyperfibrinolysis is induced by diffuse endothelial injury, with activation of the plasminogen-plasmin cascade and increased activated protein C activity. Inadequate management of coagulopathy is also one of the major potentially avoidable causes of death in trauma. In this context, massive transfusion protocols and antifibrinolytic drugs, such as tranexamic acid (ATX), a drug that acts through the competitive inhibition of plasminogen activation in plasmin, have been studied as a valuable resource in bleeding control of trauma victims, in order to reconcile safe, efficient and quick treatment. The CRASH-2 study, considered one of the largest clinical trials involving trauma victims (N = 20,211), showed that the use of ATX, when administered within 3 hours after the event, significantly reduced general and hemorrhage-related mortality without increasing the risk of thrombotic events. Since ATX is a low-cost, widely available drug, it is important to know the benefits and risks associated with its use, based on the best evidence currently available. Thus, it is the objective of this study to gather and to verify the methodological quality of evidence found by systematic reviews on the effects of ATX as a therapeutic option for the control of trauma hemorrhage, in order to contribute to a broader knowledge on the management of this important avoidable cause of mortality.