Widely used to reduce bleeding by inhibiting fibrinolysis, tranexamic acid has demonstrated clear benefits in trauma, surgery, and obstetric hemorrhage when administered early. However, not all patients respond to it identically, and clinicians currently rely on broad clinical criteria rather than direct, real-time measures of its effectiveness. As research advances, the ability to determine the pharmacologic impact of tranexamic acid at the bedside may help optimize therapy, reduce unnecessary dosing, and improve outcomes in high-risk situations. Point-of-care testing for tranexamic acid efficacy aims to bridge a critical gap between rapid treatment decisions and individualized patient response.
Because fibrinolysis is a complex process, the administration of tranexamic acid requires nuance. While excessive fibrinolysis can lead to uncontrolled bleeding, insufficient fibrinolysis may result in clot persistence and unwanted thrombosis. Tranexamic acid acts by blocking the lysine-binding sites on plasminogen, preventing its conversion to plasmin and thereby reducing clot breakdown. Yet fibrinolysis varies widely among individuals depending on their underlying physiology, the nature of their condition, and the timing of intervention. Trauma patients, for example, may progress through different phases of coagulation dysfunction within minutes of injury, and women experiencing postpartum hemorrhage may demonstrate rapid changes in fibrinolytic activity. Because of this variability, a one-size-fits-all approach to tranexamic acid administration may not be optimal.
Point-of-care coagulation assays have been explored as a way to evaluate fibrinolytic activity more directly and adjust tranexamic acid therapy accordingly. Viscoelastic tests such as thromboelastography and rotational thromboelastometry can detect increased clot breakdown and have been used in research settings to identify patients who are most likely to benefit from antifibrinolytic therapy. These tests can also reveal when fibrinolysis is already suppressed, suggesting that tranexamic acid may offer limited benefit or even pose a theoretical risk of promoting thrombosis.
Despite these possibilities, traditional viscoelastic methods have limitations. They require trained personnel, can be influenced by operator technique, and do not always correlate perfectly with clinical outcomes. Moreover, they are not specifically designed to measure the pharmacodynamic effect of tranexamic acid itself but instead provide general information about clot formation and dissolution.