What is the recommended dose of tranexamic acid (TXA) for an adult patient with hemorrhagic shock following trauma?

Tranexamic Acid Dosing for Hemorrhagic Shock Following Trauma

Administer tranexamic acid 1 gram IV over 10 minutes as a loading dose, followed by 1 gram infusion over 8 hours, and ensure administration occurs within 3 hours of injury. 1

Standard Dosing Protocol

The evidence-based regimen derived from the landmark CRASH-2 trial (20,211 patients) establishes the following protocol 1:

• Loading dose: 1 gram IV over 10 minutes 1, 2
• Maintenance infusion: 1 gram IV over 8 hours 1, 2
• Critical timing window: Administer within 3 hours of injury 1, 2

This dosing reduces all-cause mortality by 9% (relative risk 0.91) and bleeding-related death by 15% (relative risk 0.85) in trauma patients 3. The European trauma guidelines explicitly recommend this regimen as Grade 1A evidence 1.

Time-Dependent Efficacy

The effectiveness of TXA decreases by 10% for every 15-minute delay in administration 3, 2. The mortality benefit varies dramatically by timing 3:

• ≤1 hour from injury: 32% reduction in bleeding death (relative risk 0.68) 3
• 1-3 hours from injury: 21% reduction in bleeding death (relative risk 0.79) 3
• >3 hours from injury: Paradoxical increase in bleeding death risk (relative risk 1.44) 3, 2

Consider pre-hospital administration to ensure treatment within the critical window 1, 4.

Alternative Dosing Considerations

Recent evidence from 2024-2025 suggests flexibility in dosing strategies 5, 4:

• Single 2-gram bolus: A comparative analysis of 525 trauma patients showed equivalent 28-day mortality (21%) between 1-gram bolus, 1-gram + 1-gram infusion, and 2-gram bolus groups 5
• Simplified regimen: The joint position statement from NAEMSP, ACEP, and ACS-COT (2025) indicates EMS agencies may administer either the traditional 1-gram dose (followed by hospital-based infusion) or a 2-gram IV/IO dose as infusion or slow push 4

However, the 1-gram loading dose followed by 1-gram infusion over 8 hours remains the gold standard with the strongest evidence base 1, 3, and single bolus administration is likely preferable to bolus plus infusion when logistically simpler 5.

Patient Selection Criteria

Administer TXA to trauma patients who are 1, 4:

• Actively bleeding or at risk of significant hemorrhage 1
• Presenting with clinical signs of hemorrhagic shock 4
• Within 3 hours of injury 1, 4

Do not restrict TXA use only to the most severely injured or those with confirmed hyperfibrinolysis—this approach would result in thousands of avoidable deaths 6.

Safety Profile

TXA demonstrates excellent safety in trauma populations 1, 3:

• No increased risk of thrombotic events (myocardial infarction, stroke, DVT, pulmonary embolism) in over 8,000 patients 3
• The CRASH-2 trial showed lower rates of thrombosis, especially myocardial infarction, with TXA use 1
• No adverse events were described in the CRASH-2 trial 1

Critical Contraindications and Cautions

Avoid TXA in patients with traumatic subarachnoid hemorrhage, as routine antifibrinolytic therapy does not improve functional outcomes in intracranial bleeding 7. The standard trauma dosing does not apply when intracranial subarachnoid bleeding is present 7.

Dose adjustment is required in renal impairment, as TXA is renally excreted and accumulates in renal failure 3.

Key Clinical Pitfalls to Avoid

• Do not delay administration waiting for laboratory confirmation of coagulopathy or hyperfibrinolysis—early aggressive treatment improves outcomes 1, 6
• Do not administer TXA after 3 hours post-injury, as this may increase bleeding death risk 3, 2
• Do not withhold TXA due to thrombotic concerns in appropriate bleeding scenarios—the mortality benefit from reduced bleeding far outweighs theoretical thrombotic risk 3
• Clearly communicate TXA administration to receiving healthcare professionals to avoid duplicate dosing and ensure appropriate monitoring 4