How should we bridge anticoagulation for a patient with an orthopedic (ortho) ankle fracture, last dose of anticoagulant was on [DATE], taking a one-time dose of aspirin (acetylsalicylic acid) 324mg, to minimize thrombotic and bleeding complications?

Bridging Anticoagulation for Ankle Fracture Surgery

For this patient undergoing orthopedic ankle fracture surgery, bridging anticoagulation is likely NOT indicated, and the single dose of aspirin 324 mg provides adequate thromboprophylaxis without requiring additional bridging therapy.

Key Decision Points

Determining Need for Bridging

The critical first step is identifying what anticoagulant ("liquid") the patient was taking and their thromboembolic risk stratification. Without knowing the specific anticoagulant and indication, the default approach for most patients undergoing orthopedic surgery is:

• High thromboembolic risk patients (mechanical heart valve, atrial fibrillation with CHADS2 ≥5, recent VTE within 3 months, severe thrombophilia): Consider bridging with therapeutic-dose LMWH 1
• Moderate-to-low risk patients (atrial fibrillation with CHADS2 2-4, VTE >12 months ago): Bridging is generally NOT recommended due to increased bleeding risk without thrombotic benefit 2

Ankle Fracture Surgery Bleeding Risk

Orthopedic ankle fracture surgery is considered moderate-to-high bleeding risk due to:

• Bone and soft tissue trauma 3
• Potential for compartment syndrome complications 3
• Need for adequate surgical hemostasis 1

This bleeding risk profile argues strongly against routine bridging anticoagulation 2.

Recommended Management Algorithm

Preoperative Phase

If the patient was on warfarin:

• Last dose should have been 5 days before surgery 1
• Check INR day before surgery; proceed if INR ≤1.5 1
• If INR 1.5-1.8, give oral vitamin K 1-2.5 mg 1
• Do NOT initiate bridging LMWH unless patient is truly high-risk (mechanical valve, recent stroke) 2

If the patient was on a DOAC:

• Standard interruption based on renal function (typically 2-3 days) 2
• No bridging indicated - DOACs have short half-lives making bridging unnecessary and harmful 2

Current Situation (Day of Surgery)

The aspirin 324 mg one-time dose is appropriate for VTE prophylaxis in orthopedic surgery:

• Aspirin provides effective thromboprophylaxis for major orthopedic procedures 3
• Perioperative aspirin use in foot/ankle surgery shows minimal bleeding complications (0.80% wound complication rate) 4
• Recent evidence supports aspirin as standalone prophylaxis in selected orthopedic patients 3

Postoperative Management

Resume oral anticoagulant without bridging:

• Restart warfarin at usual maintenance dose on evening of surgery or next morning 1
• Resume DOAC 24-48 hours post-surgery once hemostasis achieved 2
• Do NOT use therapeutic-dose LMWH bridging postoperatively 2

If bridging were absolutely necessary (high-risk patient only):

• Delay LMWH resumption for 48-72 hours after surgery for high-bleeding-risk procedures 1
• Use reduced-dose or prophylactic-dose LMWH initially rather than therapeutic dose 1
• Major bleeding occurs in 20% when therapeutic LMWH started 12-24 hours post-major surgery 1

Critical Evidence Against Routine Bridging

Recent high-quality evidence demonstrates:

• Two-to-three-fold increase in major bleeding with heparin bridging 2
• No reduction in stroke or thromboembolism with bridging 2
• Similar adverse event rates between LMWH and UFH bridging (16.2% vs 17.1%) 5
• Postoperative bridging should be used with extreme caution in patients undergoing major surgery 5

Common Pitfalls to Avoid

• Do not reflexively bridge all anticoagulated patients - this outdated practice increases bleeding without reducing thrombosis 2
• Do not start therapeutic-dose LMWH within 24 hours post-surgery - this dramatically increases major bleeding risk (20% incidence) 1
• Do not give last preoperative LMWH dose <24 hours before surgery - 34% of patients have therapeutic anticoagulation at surgery when dosed 12 hours prior 1
• Do not confuse aspirin with full anticoagulation - aspirin alone is often sufficient for orthopedic VTE prophylaxis 3, 4

Specific Answer for This Patient

Given the information provided:

1. The aspirin 324 mg is adequate thromboprophylaxis 3, 4
2. Do not initiate bridging anticoagulation unless this is a mechanical heart valve patient or other truly high-risk indication 2
3. Resume the original oral anticoagulant on evening of surgery or next morning at usual dose 1
4. If absolutely required to bridge (high-risk only), wait 48-72 hours post-surgery before starting even prophylactic-dose LMWH 1