Tranexamic Acid Use

Preoperative Assessment for TXA Use

Preoperative Laboratory Assessment

Renal Function and Dose Adjustment

Risk Stratification and Contraindication Assessment

Thrombophilia Screening

Should patients be screened for thrombophilia before TXA? No routine thrombophilia screening is recommended.

• Surgical meta-analyses show no clear increase in VTE risk with TXA at therapeutic doses
• Thrombophilia testing is expensive and rarely changes management
• Patients with known thrombophilia can still receive TXA with appropriate VTE prophylaxis
• Reserve individualised discussion for severe hereditary thrombophilia

Intraoperative and Postoperative Monitoring

Routine TXA use does not require coagulation studies, D-dimer or fibrinogen monitoring (PT/aPTT are unaffected). Direct investigation only to a specific suspected adverse event:

TXA Dosing Protocols by Procedure

Route Selection

Decision Algorithm for TXA Administration

Confirm eligibility: check renal function (eGFR), review contraindications (active VTE, seizure history), complete standard preoperative workup, and document the TXA plan.

Choose route:

• Standard patient: IV or topical (equivalent efficacy)
• Renal impairment: Topical preferred, or reduced IV dose
• Seizure history: Topical preferred
• Patient preference: Either route acceptable

Optimise timing:

• IV bolus: 10-15 minutes before skin incision
• Topical: applied at end of procedure before closure
• Combined: IV pre-incision + topical at closure (no clear added benefit in most studies)

Consider repeat dose if: procedure over 3 hours (half-life 2-3 hours), ongoing significant blood loss, or revision/complex reconstruction. Dose: half the initial dose, or full dose at 3 hours; do not exceed about 3g total IV.

Evidence-Based Dosing Strategies

The Fillingham network meta-analyses underpinning the combined AAOS/AAHKS/Hip and Knee Society/ASRA guideline found that topical, IV and oral TXA were all superior to placebo, with no formulation, dose, dosing frequency or timing clearly superior in either TKA or THA. Moderate evidence supported pre-incision IV administration in TKA.

Special Population Management

Trauma-Specific Management (CRASH-2 Protocol)

Oral and Postoperative Dosing

Oral TXA (2g approximately 2 hours preoperatively, bioavailability around 45%) is an emerging cost-effective alternative with efficacy comparable to IV in TJA network meta-analysis. Routine postoperative TXA dosing is not required; a single 1g IV dose at around 3 hours may be considered only if there is ongoing oozing or concern for late fibrinolysis.

Management of Bleeding Despite TXA

• Verify TXA delivery: correct timing (pre-incision), adequate dose, consider repeat if over 3 hours elapsed
• Surgical control: electrocautery, bone wax, topical haemostatics, direct pressure
• Resuscitation: point-of-care Hb (transfuse if Hb less than 70-80 g/L), correct hypothermia and acidosis, FFP/platelets if coagulopathic
• Pharmacological: additional TXA up to about 3g total; aminocaproic acid is an alternative antifibrinolytic (aprotinin was withdrawn for renal/cardiac toxicity)

TXA Administration Techniques

Procedure-Specific Considerations

Technical Considerations for Topical Application

Tourniquet and TXA Interaction (TKA)

TXA timing is pre-incision regardless of tourniquet strategy. Given systemically before inflation, therapeutic plasma levels are present to control the reactive bleeding that occurs when the tourniquet is released, whether tourniquet is used throughout, for cementation only, or not at all.

Combined IV and Topical Administration

The theoretical rationale (systemic plus high local concentration) is attractive, but multiple RCTs show no significant additional benefit over a single route. A combined protocol (IV 15-20mg/kg pre-incision plus topical 2-3g at closure) is safe and can be reserved for high-bleeding-risk cases (revision, complex primary).

Technical Pearls

• IV: slow infusion prevents hypotension; compatible with most IV fluids
• Topical: can soak an absorbable gelatin sponge in TXA for additional local effect; avoid mixing with blood products; some surgeons atomise the solution for even distribution
• Repeat intraoperatively if procedure over 3 hours, unexpected bleeding, or large revision surface area

Overview of TXA Safety

Thromboembolic Safety

Seizure Risk

Mechanism: at high plasma concentrations (over about 80-100 micrograms/mL) TXA acts as a GABA-A receptor antagonist, lowering seizure threshold. Orthopaedic doses rarely reach these levels. If a TXA-related seizure occurs: stop the infusion, protect the airway, give a benzodiazepine, check glucose, document, and avoid future TXA use.

Detailed Thromboembolic Data

CRASH-2 vascular events were no different between groups (no increase in DVT, PE, stroke or MI), reinforcing safety even in a high-risk trauma population without routine chemical prophylaxis. In the Ker surgical meta-analysis (129 trials, 10,488 patients), point estimates for thromboembolic events did not show a clear increase: DVT RR 0.86 (95% CI 0.53-1.39), PE RR 0.61 (0.25-1.47), MI RR 0.68 (0.43-1.09), stroke RR 1.14 (0.65-2.00), all with wide confidence intervals; transfusion was reduced by about one third (RR 0.62).

Contraindications (Consolidated)

Drug Interactions and Concurrent Anticoagulation

Rare Complications and Special Populations

• Visual disturbance / retinal toxicity: extremely rare, reported with prolonged oral use (e.g. menorrhagia), not with short-term perioperative use
• Allergic reactions: very rare; anaphylaxis not reported at standard doses
• Renal impairment: half-life prolonged to 4-8 hours; higher plasma levels increase seizure risk; reduce dose by 50% if eGFR 10-30, avoid if eGFR less than 10, and give after dialysis
• Pregnancy: limited data; reserve for life-threatening bleeding

Postoperative Monitoring After TXA

Transfusion and VTE Prophylaxis

Continue standard VTE prophylaxis (mechanical plus chemical, with extended chemical prophylaxis for TKA/THA) and standard restrictive transfusion thresholds (Hb less than 70 g/L for most patients; 70-80 g/L if symptomatic or cardiac disease). TXA reduces but does not eliminate transfusion need (transfusion rate roughly 2-5% with TXA versus 15-25% without).

Wound Care and Rehabilitation

Standard wound care applies; TXA typically reduces wound haematoma. Rehabilitation and mobilisation are unchanged, with early mobilisation Day 0 or Day 1. If excessive drainage or haematoma develops, the TXA effect has usually worn off (half-life 2-3 hours) and the priority is to assess for surgical bleeding rather than routinely re-dose.

Managing Ongoing Postoperative Bleeding

Criteria for concern: drain output over 500mL in the first 4 hours, expanding wound haematoma, Hb drop greater than 30 g/L, or haemodynamic instability.

Conservative measures: compression dressing and ice, reverse excessive anticoagulation, consider an additional TXA dose (1g IV) if within about 6 hours of surgery, and transfuse if indicated.

Indications for return to theatre: expanding haematoma compromising the wound, haemodynamic instability despite resuscitation, drain output greater than 1500mL in 6-8 hours, or suspected arterial bleeding.

Enhanced Recovery (ERAS) Integration

Complications reduced by TXA: transfusion requirements, wound haematoma, reoperation for bleeding. Complications not increased by TXA: DVT, PE, wound infection, periprosthetic joint infection. Uncertain/dose-dependent: seizures (only at very high doses or renal impairment), retinal toxicity (not with short-term use).

Primary Outcomes

Key Outcome Metrics

Cost-Effectiveness

TXA is one of the most cost-effective interventions in orthopaedic surgery and is generally cost-saving (a dominant strategy that both saves money and improves outcomes):

• TXA cost: very low, of the order of a few units of currency per gram (roughly 10-30 per patient)
• Transfusion cost: a single unit costs hundreds (including testing, administration and monitoring), plus the cost of transfusion-related complications
• Net effect: reduced transfusion of the order of 15-20% absolute, NNT roughly 5-10 to prevent one transfusion, with net savings of several hundred per patient
• Indirect benefits: shorter length of stay, fewer transfusion-related complications, reduced blood-bank burden

Landmark Trial and Meta-Analysis Evidence

CRASH-2 (trauma): all-cause mortality 14.5% vs 16.0% (RR 0.91, p=0.0035); death due to bleeding 4.9% vs 5.7% (RR 0.85, p=0.0077); no increase in vascular occlusive events. Benefit confined to administration within 3 hours of injury; NNT roughly 67 to save one life.

CRASH-3 (traumatic brain injury): 12,737 patients; in those treated within 3 hours, head-injury-related death 18.5% vs 19.8% (RR 0.94), with significant benefit in mild-to-moderate TBI (RR 0.78) and no increase in seizures or vascular occlusive events.

Ker surgical meta-analysis: 129 trials, 10,488 patients; transfusion reduced by about one third (RR 0.62); thromboembolic effects uncertain with no clear increase.

Fillingham network meta-analyses (TKA and THA): all TXA routes superior to placebo for blood loss and transfusion, with no route, dose, dosing frequency or timing clearly superior. These underpin the combined AAOS/AAHKS/Hip Society/Knee Society/ASRA guideline.

POISE-3 (noncardiac surgery): 9535 patients; composite bleeding outcome 9.1% vs 11.7% (HR 0.76, p less than 0.001 for superiority); cardiovascular composite 14.2% vs 13.9% (HR 1.02), with formal noninferiority not established.

Route Comparison Outcomes

Xie et al. (Thrombosis Research 2017) found similar transfusion requirements between IV and topical TXA in THA/TKA, with a marginally smaller maximum haemoglobin drop with IV. Overall there is no clinically significant difference between routes; choose based on patient factors and surgeon preference.

Subspecialty and Long-Term Outcomes

• Spine surgery: 20-40% blood-loss reduction, most beneficial in multilevel fusions and deformity correction; no increase in epidural haematoma or neurological complications; does not affect MEP/SSEP monitoring
• Hip fracture and periarticular trauma: reduced transfusion; give as early as possible, ideally within 3 hours
• Shoulder arthroplasty: limited but consistent evidence (blood-loss reduction), topical feasible
• Long term: no delayed VTE signal, no increase in implant failure/revision, no delayed wound complications

Total Knee Arthroplasty (TKA)

• Network meta-analysis and multiple RCTs demonstrate consistent 30-50% reduction in blood loss and a fall in transfusion from roughly 20% to under 5%
• No clear increase in symptomatic VTE
• Routes: IV (15-20mg/kg pre-incision), topical (2-3g in 50-100mL saline, 5-10 min dwell), combined (no clear added benefit), oral (1-2g pre-op, emerging) - none clearly superior
• Outcomes: mean blood-loss reduction 300-500mL; no difference in infection, wound complications or thrombosis

Total Hip Arthroplasty (THA)

• 30-40% blood-loss reduction across approaches (posterior, lateral, anterior); transfusion reduced from 15-25%
• Safe in cemented and uncemented techniques; effective in revision with higher doses considered
• Dosing: 1.5-2g IV bolus or 15-20mg/kg; topical 2-3g into acetabulum/femoral canal before final component insertion; consider repeat for prolonged procedures

CRASH-2 (landmark) randomised 20,211 trauma patients with significant bleeding to TXA (1g over 10 min then 1g over 8h) vs placebo. All-cause mortality fell from 16.0% to 14.5% (RR 0.91) and death due to bleeding from 5.7% to 4.9% (RR 0.85), with no increase in vascular occlusive events. Benefit only when given within 3 hours; harm if given later.

CRASH-3 extended this to traumatic brain injury (12,737 patients), reducing head-injury-related death in mild-to-moderate TBI when given within 3 hours, with no increase in seizures or vascular occlusive events.

Orthopaedic trauma applications: pelvic, femoral and acetabular fractures show reduced transfusion; thoracolumbar fractures requiring surgery benefit. Recommended protocol: 1g IV over 10 min then 1g over 8h, as soon as possible (ideally within 1 hour, certainly within 3 hours).

• Meta-analyses show 30-40% blood-loss reduction in scoliosis and kyphosis correction and reduced transfusion in multilevel instrumented fusions
• Dosing: loading 10-15mg/kg over 15-20 minutes before incision, then maintenance infusion 1-2mg/kg/hour throughout; alternatively bolus 10-15mg/kg repeated every 3-4 hours
• Safety: no increase in spinal epidural haematoma or neurological complications; safe with intraoperative neuromonitoring (does not affect MEP/SSEP)
• Special considerations: higher doses for revision; continue infusion across staged anterior-posterior procedures; still beneficial in minimally invasive surgery

• Fracture fixation: benefit in intra- and extra-capsular hip fractures, periarticular fractures (tibial plateau, pilon, distal femur) and long-bone fractures
• Revision arthroplasty: similar or greater benefit than primary; consider higher doses (20-25mg/kg or 2-3g) and combined IV plus topical
• Shoulder arthroplasty: emerging benefit in anatomic and reverse total shoulder, dosing similar to THA
• Foot and ankle: limited evidence; case series suggest benefit in hindfoot fusions and total ankle arthroplasty (lower doses sufficient)
• Tumour surgery: beneficial in resection of vascular bone tumours; individualise with extensive soft-tissue dissection