TXA is an antifibrinolytic (inhibits action of plasminogen), in plain language --> stops the breakdown of clots that that body builds in response to bleeding.
Natural progression in bleeding/hemorrhage is that circulating platelets and go through a conformational (shape) change when exposed to tissue factors that are released in damaged vessel lining. The clotting cascade follows and platelets, clotting factors, fibrin, all work together to form a clot.
Final step in coagulation is fibrinolysis (clot breakdown and resorption) --> which is where TXA comes in to play. It stops plasminogen from breaking down the clot.
TXA key points:
-Beneficial in casualties anticipated in needing massive transfusion
-Most effective when given early post-injury (within 3hrs, ideally less than 1hr)
-Increased morbidity/mortality when given >3hrs post-injury (not clear on why the 3hr cutoff but if anyone has access to specifics on that I'd be interested)
Lots of words past this line
but evidence supports early TXA use in trauma, the research (CRASH-2, MATTERs, and others) is interesting and it's now incorporated in TCCC.
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*** The guidelines in bold are from the TCCC reference document "SUBJECT: Recommendations Regarding the Addition of Tranexamic Acid to the Tactical Combat Casualty Care Guidelines 2011-06" I have the PDF saved if anyone wants it or you can access it here
http://www.health.mil/Education_And_Training/TCCC.aspx
Guidelines for Administration in the Deployed Setting
The early use of TXA should be strongly considered for any patient requiring blood products in the treatment of combat-related hemorrhage and is most strongly advocated in patients judged likely to require massive transfusion (e.g., significant injury and 3 or 4 risk factors/indicators of massive transfusion).
Use of TXA within 3 hours of injury is associated with the greatest likelihood of clinical benefit. The greatest benefit was seen when TXA was administered within 1 hour of wounding.
Due to this time constraint, the uncertainty of battlefield evacuation, and a good safety profile in the doses previously administered to trauma patients, use in the prehospital setting is recommended if patient monitoring and storage requirements can be met.
Military Application of Tranexamic Acid in Trauma Emergency Resuscitation (MATTERs) Study.
Morrison JJ,
Dubose JJ,
Rasmussen TE,
Midwinter MJ.
Source
US Army Institute of Surgical Research, Fort Sam Houston, TX 78234-6315, USA.
Abstract
OBJECTIVES:
To characterize contemporary use of tranexamic acid (TXA) in combat injury and to assess the effect of its administration on total blood product use, thromboembolic complications, and mortality.
DESIGN:
Retrospective observational study comparing TXA administration with no TXA in patients receiving at least 1 unit of packed red blood cells. A subgroup of patients receiving massive transfusion (≥10 units of packed red blood cells) was also examined. Univariate and multivariate regression analyses were used to identify parameters associated with survival. Kaplan-Meier life tables were used to report survival.
SETTING:
A Role 3 Echelon surgical hospital in southern Afghanistan.
PATIENTS:
A total of 896 consecutive admissions with combat injury, of which 293 received TXA, were identified from prospectively collected UK and US trauma registries.
MAIN OUTCOME MEASURES:
Mortality at 24 hours, 48 hours, and 30 days as well as the influence of TXA administration on postoperative coagulopathy and the rate of thromboembolic complications.
RESULTS:
The TXA group had lower unadjusted mortality than the no-TXA group (17.4% vs 23.9%, respectively; P = .03) despite being more severely injured (mean [SD] Injury Severity Score, 25.2 [16.6] vs 22.5 [18.5], respectively; P < .001). This benefit was greatest in the group of patients who received massive transfusion (14.4% vs 28.1%, respectively; P = .004), where TXA was also independently associated with survival (odds ratio = 7.228; 95% CI, 3.016-17.322) and less coagulopathy (P = .003).
CONCLUSIONS:
The use of TXA with blood component-based resuscitation following combat injury results in improved measures of coagulopathy and survival, a benefit that is most prominent in patients requiring massive transfusion. Treatment with TXA should be implemented into clinical practice as part of a resuscitation strategy following severe wartime injury and hemorrhage.
