When should tranexamic acid (TXA) be administered to a trauma patient with suspected significant bleeding and persistent hypotension following a high-energy mechanism, such as a motor vehicle crash?

When to Give Tranexamic Acid for Trauma

Administer tranexamic acid (TXA) immediately to any trauma patient with suspected significant bleeding or hemorrhagic shock, ideally within 90 minutes and no later than 3 hours after injury, at a loading dose of 1 g IV over 10 minutes followed by 1 g infusion over 8 hours. 1, 2

Critical Timing Window

The therapeutic window for TXA is time-dependent and directly impacts mortality:

• Optimal benefit occurs within 90 minutes of injury, where TXA reduces 28-day mortality from 25% to 17% (adjusted risk ratio 0.64,95% CI 0.50-0.82) 2
• Administration within 1 hour reduces bleeding death by 32% (RR 0.68,95% CI 0.57-0.82) 1
• Administration between 1-3 hours still provides benefit but with diminishing effect (RR 0.79,95% CI 0.64-0.97) 1
• Administration after 3 hours may increase mortality due to bleeding (RR 1.44,95% CI 1.12-1.84) and should be avoided 1
• Effectiveness decreases by 10% for every 15-minute delay 3, 4

Patient Selection Criteria

Give TXA to trauma patients who meet ANY of the following:

• Active bleeding or at risk of significant hemorrhage 1
• Clinical signs of hemorrhagic shock (persistent hypotension, tachycardia, shock index <0.9) 1, 5
• High-energy mechanism (motor vehicle crash, falls, penetrating trauma) with suspected internal bleeding 6, 7

Do NOT wait for laboratory confirmation of hyperfibrinolysis - TXA should not await viscoelastic assessment results 1

Standard Dosing Protocol

The evidence-based regimen is:

• Loading dose: 1 g IV over 10 minutes 1, 3
• Maintenance dose: 1 g IV infusion over 8 hours 1, 3

Alternative acceptable regimen for prehospital settings:

• Single 2 g IV dose as infusion or slow push (if 8-hour infusion not feasible) 5

Prehospital Administration

Consider initiating TXA en route to hospital to ensure treatment within the critical time window 1, 5

• Prehospital TXA is safe and feasible when given after lifesaving interventions 5, 8
• Patients receiving TXA within 1 hour and shock index <0.9 have 65% lower 30-day mortality (HR 0.35,95% CI 0.19-0.65) 1
• Clear communication to receiving facility is essential to avoid duplicate dosing 5

Special Considerations for Traumatic Brain Injury

TXA benefits mild-to-moderate head injury but not severe TBI:

• In mild-to-moderate TBI (GCS 9-15), TXA reduces head injury-related death (RR 0.78,95% CI 0.64-0.95) when given within 3 hours 1
• In severe TBI (GCS 3-8), no mortality benefit demonstrated (RR 0.99,95% CI 0.91-1.7) 1
• Do NOT give TXA for isolated traumatic subarachnoid hemorrhage - guidelines recommend against routine use due to lack of functional benefit 9

Universal Application Principle

The treatment effect does not vary by:

• Systolic blood pressure level 1, 7
• Glasgow Coma Scale score 1, 7
• Type of injury (blunt versus penetrating) 1, 7

Therefore, limiting TXA to only the most severely injured would result in thousands of avoidable deaths - administer to all bleeding trauma patients within the time window 1, 6

Safety Profile

TXA is remarkably safe in trauma:

• No increased risk of thrombotic events; CRASH-2 showed lower rates of myocardial infarction with TXA 1
• Low risk of seizures at standard trauma doses (1 g + 1 g regimen) 5, 8
• Higher doses (>100 mg/kg total) increase seizure risk and should be avoided 3, 4

Common Pitfalls to Avoid

Critical errors that compromise outcomes:

1. Delaying administration beyond 90 minutes - benefit diminishes rapidly and reverses after 3 hours 2, 1
2. Waiting for laboratory confirmation of coagulopathy - this wastes precious time 1
3. Restricting use to "massive transfusion protocol" patients only - this excludes 60% of patients who could benefit 1, 6
4. Giving TXA after 3 hours - this may paradoxically increase mortality 1, 4
5. Using TXA for isolated traumatic subarachnoid hemorrhage - contraindicated per stroke guidelines 9, 4