Is a warfarin (coumarin) bridge necessary when resuming warfarin (coumarin) after a temporary hold for a shoulder fracture open reduction internal fixation (ORIF) in a patient with a history of thrombosis (clot)?

From the Guidelines

A warfarin bridge is typically not necessary when resuming warfarin after it was held for a shoulder fracture ORIF in a patient with a remote history of clot. The patient can simply restart their previous maintenance dose of warfarin without overlapping with a parenteral anticoagulant like low molecular weight heparin. This approach is appropriate because the risk of developing a new clot in the immediate post-operative period is relatively low for patients with a remote history of venous thromboembolism (more than 3 months ago) 1. When resuming warfarin, INR monitoring should begin within 3-5 days of restarting therapy, with a target INR typically between 2.0-3.0 for most indications.

The decision to forego bridging therapy balances the risk of bleeding (particularly at the surgical site) against the risk of thrombosis. However, for patients with higher thrombotic risk factors (such as active cancer, multiple prior clots, or known thrombophilia), bridging therapy might still be considered, and this decision should be individualized based on the patient's specific risk profile 1. Key considerations include:

• The patient's overall risk of thrombosis and bleeding
• The type and urgency of the surgical procedure
• The patient's renal function and other comorbidities
• The availability of close monitoring and follow-up

In general, the approach to perioperative anticoagulation management should be tailored to the individual patient's needs and risk factors, taking into account the latest evidence and guidelines 1.

From the Research

Warfarin Bridge Therapy

• The decision to use a warfarin bridge therapy is determined by balancing the risk of bleeding against the risk of thromboembolism 2.
• Patients at higher risk of thromboembolization should stop warfarin therapy four to five days before surgery and start low-molecular-weight heparin (LMWH) or unfractionated heparin two to three days before surgery 2.
• The use of LMWH as a bridging agent has been shown to be safe and effective in patients with mechanical heart valves and nonvalvular atrial fibrillation 3.
• A study found that bridging therapy with therapeutic-dose enoxaparin was feasible and associated with a low incidence of major bleeding and no thromboembolic complications in patients undergoing surgery 4.

Reinitiating Warfarin

• There is limited information available on the best methods for reinitiating warfarin after temporary discontinuation 5.
• A study found that reinitiating warfarin at the same dose as before discontinuation was a common practice, but the decision to do so was not associated with specific patient demographic, clinical, medication, or hospital factors 5.
• The study suggested that patients with a previously established effective dose should be reinitiated at that same dose following temporary warfarin discontinuation, in the absence of clinical indications for modification 5.

Specific Considerations for Shoulder Fracture ORIF

• There is no direct evidence in the provided studies specifically addressing the need for a warfarin bridge therapy in patients with a history of thrombosis undergoing shoulder fracture open reduction internal fixation (ORIF).
• However, the general principles of bridging therapy and reinitiating warfarin can be applied to this scenario, taking into account the individual patient's risk of thromboembolism and bleeding 2, 3, 4, 5.