Which factor contraindicates the use of Tranexamic Acid (TXA)?

Tranexamic Acid (TXA) is an antifibrinolytic medication used in the management of bleeding, particularly in trauma settings. The timeline for the administration of TXA is critical to its effectiveness. The established guideline suggests that TXA should be administered as soon as possible and ideally within three hours of the onset of significant hemorrhage.

When administered within this time frame, TXA has been shown to reduce mortality in patients with traumatic hemorrhagic shock. However, after the three-hour mark, the potential benefits diminish significantly, as the physiological processes associated with severe bleeding and coagulopathy may advance beyond the point where TXA can be effective. Therefore, its use more than three hours after injury is contraindicated, as the drug may not provide the intended benefits and could expose the patient to unnecessary risks.

In contrast, altered mental status, ongoing severe bleeding, and the presence of a tourniquet do not inherently contraindicate the use of TXA. These factors may require careful consideration during treatment, but they do not eliminate the potential benefits of TXA when administered within the appropriate time frame.