Published: April 2026
Authors: IMBR Mentor
Topic: Pharmacology & Critical Care
Tranexamic acid (TXA) is an antifibrinolytic agent that has revolutionized the management of hemorrhagic conditions in critical care. Originally developed in the 1960s, TXA gained widespread attention following the CRASH-2 trial in 2010. This review article summarizes the current evidence, guidelines, and clinical applications of TXA in critical care settings, including trauma, surgery, obstetrics, and specific populations.
Tranexamic acid is a synthetic derivative of the amino acid lysine. Its antifibrinolytic effect works by:
| Mechanism | Detail |
|---|---|
| Competitive inhibition | Binds reversibly to lysine binding sites on plasminogen |
| Prevents plasminogen activation | Blocks conversion of plasminogen → plasmin |
| Stabilizes fibrin clot | Prevents fibrinolysis and clot breakdown |
| Feature | Tranexamic Acid | Aprotinin |
|---|---|---|
| Mechanism | Direct plasminogen inhibition | Serine protease inhibition |
| Risk of thrombosis | Lower | Higher |
| Cost | Low | High |
| Evidence base | Large (CRASH-2) | Limited |
Large, Randomized, Placebo-Controlled Trial in Trauma
| Parameter | Result |
|---|---|
| N | 20,211 adult trauma patients |
| Intervention | TXA 1g IV over 10 min, then 1g over 8 hrs vs placebo |
| Primary Outcome | All-cause mortality at 28 days |
| Result | Reduced mortality: 14.5% vs 16.0% (RR 0.91, 95% CI 0.85-0.97) |
| Number Needed to Treat (NNT) | 67 patients to prevent 1 death |
| Key Finding | Greatest benefit when given within 3 hours of injury |
CRASH-2 Mortality Benefit by Time:
< 1 hour post-injury: 32% reduction in death
1-3 hours: 21% reduction in death
> 3 hours: No benefit (may increase mortality)Tranexamic Acid for Traumatic Brain Injury
| Parameter | Result |
|---|---|
| N | 12,737 patients with mild-moderate TBI |
| Result | Non-statistically significant reduction in head injury-related death |
| Subgroup Analysis | Possible benefit in severe TBI with GCS ≤8 |
| Safety | No increase in adverse events |
Tranexamic Acid for Postpartum Hemorrhage
| Parameter | Result |
|---|---|
| N | 20,060 women with PPH |
| Result | Reduced death from PPH (1.5% vs 1.9%, p=0.03) |
| NNT | ≥ 500 women (less effective than in trauma) |
| Key Finding | Greatest benefit when given within 3 hours of birth |
National Institute for Health and Care Excellence
| Setting | Recommendation |
|---|---|
| Surgery with bleeding risk | Offer TXA if breach of skin/mucosa in operating theatre |
| Outside operating theatre | Consider TXA if expected blood loss >500 mL |
| Trauma | Continue current practice per CRASH-2 protocol |
| Pediatric surgery | Draft guidance extending to children (2025) |
Eastern Association for the Surgery of Trauma
| Setting | Recommendation | Evidence |
|---|---|---|
| Pre-hospital TXA | Conditional recommendation | Low-quality evidence |
| In-hospital TXA | Conditional recommendation | Significant mortality reduction at 24 hrs and 1 month |
| Dosing | 1g bolus + 1g infusion over 8 hrs (standard) | CRASH-2 protocol |
Prehospital TXA Administration
| Recommendation | Details |
|---|---|
| Adult trauma with hemorrhagic shock | Recommend prehospital TXA |
| Timing | Administer within 3 hours of injury |
| Pediatric trauma | Role not extensively studied; if used, within 3 hours |
| Safety | Low risk of thromboembolic events and seizures |
| GI Bleeding Type | Recommendation |
|---|---|
| Upper GI bleeding | Possible mortality reduction (mixed evidence) |
| Lower GI bleeding | Strong recommendation AGAINST antifibrinolytics |
╔════════════════════════════════════════════════════════════╗
║ TRANEXAMIC ACID — STANDARD ADULT PROTOCOL ║
╠════════════════════════════════════════════════════════════╣
║ Loading dose: 1 gram IV over 10 minutes ║
║ Maintenance: 1 gram IV over 8 hours ║
║ Total dose: 2 grams over 8 hours ║
║ ║
║ Alternative (hemorrhagic shock): ║
║ • 1g IV bolus over 10 min, repeat once over 8 hrs ║
║ • Maximum: 2 grams total ║
╚════════════════════════════════════════════════════════════╝| Weight | Loading Dose | Maintenance |
|---|---|---|
| <50 kg | 20 mg/kg IV over 10 min | 10 mg/kg/hr over 8 hrs |
| ≥50 kg | Adult dosing | Adult dosing |
| Population | Consideration |
|---|---|
| Renal impairment | Reduce dose (TXA is renally excreted) |
| History of seizures | Relative contraindication (TXA lowers seizure threshold) |
| DIC | Relative contraindication |
| Pregnancy | Can use in PPH (WOMAN trial data) |
| Contraindication | Reason |
|---|---|
| Hypersensitivity to TXA | Risk of anaphylaxis |
| Active venous or arterial thrombosis | Risk of extension |
| Subarachnoid hemorrhage | Theoretical risk of vasospasm |
| Caution | Clinical Concern |
|---|---|
| History of convulsions | TXA can precipitate seizures |
| Severe renal impairment | Drug accumulation |
| DIC | May worsen coagulopathy |
| History of thromboembolism | Risk of recurrence |
| System | Adverse Effect | Frequency |
|---|---|---|
| GI | Nausea, vomiting, diarrhea | Common |
| CNS | Seizures (especially with high dose/rapid infusion) | Rare |
| CV | Hypotension (with rapid IV push) | Rare |
| Thromboembolic | DVT, PE (low risk per CRASH-2) | Rare |
Algorithm for TXA in Trauma:
Trauma Patient with Bleeding
│
▼
Hemorrhagic shock?
(SBP <90, HR >110)
│
┌─────┴─────┐
│ │
▼ ▼
YES NO
│ │
▼ ▼
Give TXA Monitor closely
within 3 hrs Consider TXA if
significant bleeding
develops| Surgery Type | Evidence | Recommendation |
|---|---|---|
| Cardiac surgery | Mixed results | Consider in high-risk patients |
| Orthopedic surgery | Effective for reducing blood loss | Recommend |
| Spinal surgery | Effective | Recommend |
| Major abdominal surgery | Limited data | Case-by-case |
TXA is recommended as part of massive transfusion in:
| Protocol | Role |
|---|---|
| 1:1:1 (PRBC:FFP:Platelets) | TXA added as 1g loading dose |
| Critical bleeding protocols | Early administration within 3 hours |
| Year | Development | Impact |
|---|---|---|
| 2025 | NICE draft — wider TXA use in surgery | More patients eligible |
| 2025 | EAST updated guidelines — in-hospital TXA | Stronger recommendation |
| 2025 | NAEMSP/ACEP/ACS-COT position — prehospital TXA | Standardizes prehospital use |
| 2026 | NICE final guidance (simplified criteria) | Easier clinical decision-making |
| Question | Status |
|---|---|
| Optimal dose in severe trauma | Under investigation (TXA loading dose study) |
| TXA in pediatric trauma | Limited evidence, ongoing research |
| Topical TXA vs IV TXA | Topical appears effective with lower systemic risk |
| TXA in gastrointestinal bleeding | Evidence remains mixed |
┌─────────────────────────────────────────────────────────────┐
│ TAKE-HOME POINTS │
├─────────────────────────────────────────────────────────────┤
│ 1. TXA works best when given EARLY — within 3 hours │
│ of injury/bleeding onset │
│ │
│ 2. Standard dose: 1g IV bolus + 1g over 8 hours │
│ (or 2g total over 8 hours) │
│ │
│ 3. In trauma with hemorrhage: GIVE TXA │
│ (NNT = 67 to prevent 1 death) │
│ │
│ 4. TXA is underutilized — benefit-risk ratio is favorable │
│ │
│ 5. Contraindications: active thrombosis, seizures, │
│ severe renal impairment │
│ │
│ 6. Do NOT give TXA >3 hours post-injury │
│ (may increase mortality) │
└─────────────────────────────────────────────────────────────┘| Feature | Tranexamic Acid | Aminocaproic Acid |
|---|---|---|
| Potency | Higher | Lower |
| Dosing frequency | Lower (longer half-life) | Higher |
| Evidence | Extensive (CRASH-2, etc.) | Limited |
| Cost | Low | Low |
| Clinical use | First-line | Alternative |
CRASH-2 trial collaborators. Effects of tranexamic acid on death, vascular occlusive events, and blood transfusion in trauma patients with significant haemorrhage (CRASH-2): a randomised, placebo-controlled trial. Lancet. 2010;376(9734):23-32. doi:10.1016/S0140-6736(10)60835-5
CRASH-3 trial collaborators. Effects of tranexamic acid on death, disability, vascular occlusive events and other morbidities in patients with acute traumatic brain injury (CRASH-3): a randomised, placebo-controlled trial. Lancet. 2019;394(10210):1713-1723. doi:10.1016/S0140-6736(19)30500-X
WOMAN Trial Collaborators. Effect of early tranexamic acid administration on mortality, hysterectomy, and other morbidities in women with post-partum haemorrhage (WOMAN): an international, randomised, double-blind, placebo-controlled trial. Lancet. 2017;389(10084):2105-2116. doi:10.1016/S0140-6736(17)30638-4
NICE. Tranexamic acid for reducing the need for blood cell transfusion and managing bleeding. Draft guidance. November 2025.
EAST Guidelines. Updated trauma guidelines for TXA use. 2025.
National Association of EMS Physicians (NAEMSP), American College of Emergency Physicians (ACEP), American College of Surgeons Committee on Trauma (ACS-COT). Joint position statement on prehospital TXA. September 2025.
American College of Gastroenterology. ACG Clinical Guidelines: Gastrointestinal Bleeding. 2023.
Frontiers in Medicine. The benefit-risk profile of tranexamic acid in trauma, obstetrics, and at-risk surgeries: A narrative review. 2024. doi:10.3389/fmed.2024.1416998
Document Info: - Created: April 2026 - Last updated: April 2026 - Version: 1.0 - File: FOR OPENCLAW/IMBR/Review/Tranexamic-Acid-in-Critical-Care.md