What is the recommended duration of Deep Vein Thrombosis (DVT) prophylaxis post hip fracture surgery?

Duration of DVT Prophylaxis Post Hip Fracture Surgery

For hip fracture surgery, administer pharmacological DVT prophylaxis for a minimum of 7-10 days, with strong consideration for extended prophylaxis up to 35 days in all patients, as the risk of venous thromboembolism persists well beyond hospital discharge. 1, 2

Standard Duration: Minimum 7-10 Days

• All patients undergoing hip fracture surgery should receive pharmacological prophylaxis for at least 7-10 days postoperatively 1
• This minimum duration applies regardless of the specific anticoagulant agent selected 1
• Evidence supporting this duration comes from consensus between American College of Chest Physicians (ACCP) and International Union of Angiology (IUA) guidelines 1

Extended Prophylaxis: Up to 35 Days

Extended prophylaxis for approximately 4-5 weeks (up to 35 days total) should be strongly considered for all hip fracture patients, as this significantly reduces the persistent DVT risk that extends well beyond hospital discharge. 2, 3

• The SAVE-HIP3 trial demonstrated that extended semuloparin prophylaxis (total ~30 days) reduced VTE or all-cause mortality from 18.6% to 3.9% compared to stopping at 7-10 days (OR 0.18,95% CI 0.07-0.45, P<0.001) 1
• Six randomized double-blind trials have shown that extended prophylaxis significantly reduces the continuing DVT risk of 12-37% that persists after hospital discharge 2
• The risk of VTE after hip fracture surgery can persist for up to 2-3 months postoperatively, supporting extended prophylaxis 2, 3

Preferred Pharmacological Agents

Low molecular weight heparin (LMWH) is the preferred agent for DVT prophylaxis in hip fracture surgery. 1, 2

• LMWH should be started before surgery if surgery is delayed, or as soon as hemostasis is shown after surgery 1
• Standard dosing is enoxaparin 40 mg once daily or 30 mg twice daily 1, 4
• For extended prophylaxis, continue LMWH 40 mg once daily for the full duration 2, 5

Alternative Agents

• Fondaparinux is considered an equal alternative to LMWH 2
• Direct oral anticoagulants (rivaroxaban 10 mg once daily, apixaban) are effective alternatives with potentially better patient compliance 2, 3
• Adjusted-dose warfarin (target INR 2.0-3.0) is acceptable but more complex to manage 1, 2

Timing of Initiation

• Start LMWH before surgery if surgery is delayed, or as soon as possible after surgery once hemostasis is achieved 1
• For DOACs, initiate 12-24 hours after surgery when hemostasis is established 3
• The Norwegian national study of 45,000 hip fracture patients found that pre-operative prophylaxis did not influence mortality or reoperation risk, but post-operative prophylaxis decreased intraoperative bleeding complications for certain fixation methods 1

High-Risk Patients Requiring Extended Prophylaxis

All hip fracture patients should be considered high-risk and receive extended prophylaxis, with particular attention to: 2, 3

• History of previous VTE 3
• Active cancer 3
• Limited mobility 3
• Age >75 years 1
• Prolonged ICU or hospital length of stay 1

Mechanical Prophylaxis Adjuncts

• Intermittent pneumatic compression (IPC) devices or elastic stockings provide additional efficacy when combined with pharmacological prophylaxis 2
• Mechanical prophylaxis alone should only be used in patients with high bleeding risk, active bleeding, or coagulopathy 1, 2
• IPC should be used for a goal of 18 hours daily when employed 3

Critical Contraindications and Delays

Delay pharmacological prophylaxis in the presence of: 1

• Active bleeding
• Coagulopathy
• Hemodynamic instability
• Traumatic brain injury
• Spinal trauma

In these situations, use mechanical prophylaxis until the patient stabilizes and bleeding risk decreases 1

Bleeding Risk Considerations

• Major bleeding with LMWH occurs in approximately 1.0-1.4% of hip fracture patients 1, 6
• Extended LMWH prophylaxis (6 weeks) has significantly lower major bleeding rates (1.4%) compared to oral anticoagulants (5.5%) 5
• The benefit-risk ratio strongly favors extended LMWH over warfarin for post-discharge prophylaxis 5

Common Pitfalls to Avoid

• Stopping prophylaxis at hospital discharge: The DVT risk remains elevated at 19.3% without continued prophylaxis versus 7.1% with extended treatment 7
• Inadequate duration despite guidelines: This remains the most common error in clinical practice 3
• Using aspirin as sole therapy: This is explicitly not recommended by ACCP guidelines 1
• Failure to adjust for renal function: This can lead to bleeding complications, particularly with renally-cleared agents 3