Can wounds be sutured in patients on warfarin (anticoagulant) with an International Normalized Ratio (INR) of 2.5?

Wound Suturing in Patients on Warfarin with INR 2.5

Yes, you can safely suture wounds in patients on warfarin with an INR of 2.5, as this falls within the therapeutic range (2.0-3.0) for most indications and does not require reversal or procedure delay for minor surgical interventions.

Risk Assessment Framework

The decision to proceed with suturing depends on classifying the procedure as low-bleeding risk versus high-bleeding risk:

Low-Bleeding Risk Procedures

• Simple laceration repair and wound suturing are considered low-bleeding risk procedures that can be performed safely without interrupting anticoagulation 1
• For low-bleeding risk procedures, patients can proceed with surgery when INR ≤ 1.5 is the target, but an INR of 2.5 in the therapeutic range (2.0-3.0) is acceptable for minor procedures 1
• The therapeutic INR range of 2.0-3.0 is considered to have a "modest" risk of clinically important bleeding for surgical procedures 1

When to Proceed Without Warfarin Interruption

• An INR of 2.5 represents optimal therapeutic anticoagulation for most indications including atrial fibrillation, venous thromboembolism, and bileaflet mechanical valves 1, 2
• The risk of major bleeding during oral anticoagulant therapy at therapeutic INR (2.0-3.0) is approximately 3% per year with a case fatality rate of 0.6%, which is acceptable for most clinical scenarios 1
• Bleeding risk becomes clinically unacceptable only when INR exceeds 5.0 2

Practical Management Algorithm

For Simple Wound Suturing (Low-Bleeding Risk):

1. Verify current INR is 2.5 and within therapeutic range (2.0-3.0) 1, 2
2. Proceed with wound suturing without warfarin interruption or reversal 1
3. Use meticulous hemostatic technique during the procedure 1
4. Resume or continue warfarin at maintenance dose on the evening of or morning after the procedure 1

For Complex or High-Bleeding Risk Wounds:

• If the wound is extensive, involves highly vascular tissue, or has high bleeding risk characteristics, consider the formal perioperative bridging protocol 1
• Stop warfarin 5-6 days before procedure 1
• Check INR before procedure; proceed if INR ≤ 1.5 1
• If INR is 1.5-1.8, consider low-dose oral vitamin K (1-2.5 mg) 1

Critical Considerations

Thromboembolic Risk vs Bleeding Risk Trade-off

• The case fatality rate from recurrent thromboembolism (5-7%) is higher than the case fatality rate from anticoagulant-related bleeding (0.6%) 1
• This risk-benefit analysis supports maintaining anticoagulation for low-bleeding risk procedures 1
• One feasibility study demonstrated that continuing warfarin at INR 1.5-2.0 for invasive procedures in high-risk patients resulted in only 2 major bleeding events and 1 thrombotic event in 100 patients 3

Common Pitfalls to Avoid

• Do not routinely discontinue warfarin for simple wound suturing - this unnecessarily exposes patients to thromboembolic risk 1
• Do not administer vitamin K for an INR of 2.5 - this is therapeutic, not elevated 4, 5
• Do not use bridging anticoagulation for low-bleeding risk procedures - this increases bleeding risk without clear benefit 1, 6
• Avoid excessive concern about an INR of 2.5 - the exponential increase in bleeding risk occurs above INR 5.0, not at therapeutic levels 2, 7

Special Patient Populations

• For elderly patients (>75 years), an INR of 2.5 may carry slightly higher bleeding risk, but this remains within acceptable therapeutic range 1, 2
• Patients with mechanical mitral valves requiring higher target INR (2.5-3.5) can still undergo low-bleeding risk procedures at INR 2.5 1, 2