What is the recommended DVT (Deep Vein Thrombosis) prophylaxis for a patient with a hip fracture?

DVT Prophylaxis for Hip Fracture Patients

Low molecular weight heparin (LMWH) is the preferred pharmacological agent for DVT prophylaxis in hip fracture patients, with enoxaparin 30 mg subcutaneously twice daily starting 12-24 hours after surgery and continuing for 10-14 days, with extension up to 35 days recommended for optimal outcomes. 1, 2

Risk Assessment and Prophylaxis Algorithm

1. All hip fracture patients should receive DVT prophylaxis due to their high risk of venous thromboembolism (VTE)

   • Without prophylaxis, DVT occurs in up to 60% of hip fracture patients 3
   • Clinical symptoms are only seen in 1-3% of DVTs and 0.5-3% of PEs in these patients 2

2. Pharmacological options (in order of preference):

   • First choice: LMWH (enoxaparin)

     • Dosing: 30 mg subcutaneously twice daily 1
     • Timing: Start 12-24 hours after surgery (not before) 2, 1
     • Duration: 10-14 days minimum, extended to 35 days recommended 1, 3

   • Alternative: Fondaparinux

     • Dosing: 2.5 mg subcutaneously once daily 4
     • Timing: Start 6-8 hours after hemostasis is established 4
     • Duration: 5-9 days standard, with extension up to 24 additional days (total 32 days) 4

   • Alternative: Rivaroxaban

     • Dosing: 10 mg orally once daily 1
     • Timing: Start 6-10 hours after surgery 1

   • Alternative: Unfractionated heparin (UFH)

     • Dosing: 5000 U subcutaneously every 8 hours 2
     • Use primarily when LMWH is contraindicated or in patients with severe renal insufficiency 2

Evidence Supporting LMWH as First Choice

1. Superior efficacy and safety profile:

   • LMWH is associated with lower incidence of DVT (P=0.007) and PE (P<0.001) compared to UFH 2
   • LMWH shows fewer bleeding complications and transfusions (P<0.001) 2
   • LMWH demonstrates lower rates of myocardial infarction (P<0.0001), cardiac arrest (P=0.001), severe sepsis (P<0.001), and mortality (P<0.001) 2

2. Extended prophylaxis benefits:

   • Extended prophylaxis (≥28 days) is associated with 67% lower odds of death compared to short-duration prophylaxis 3
   • Significantly lower rates of stroke/CVA (OR 0.44, p=0.0010) and acute kidney injury (OR 0.31, p=0.0010) with extended prophylaxis 3

Special Considerations and Precautions

1. Timing considerations:

   • For patients on daytime trauma lists, administer LMWH between 18:00-20:00 to minimize bleeding risk related to neuraxial anesthesia 2
   • Avoid administering fondaparinux earlier than 6-8 hours after surgery due to increased bleeding risk 4

2. Renal function:

   • For patients with severe renal impairment (CrCl <30 mL/min):
     • Avoid fondaparinux 2
     • Consider UFH 5000 U every 8 hours instead of LMWH 2
   • For moderate renal impairment (CrCl 30-50 mL/min):
     • Use LMWH with caution and consider dose adjustment 2

3. Age considerations:

   • For patients >65 years: Initial dose of enoxaparin should be 30 mg every 12 hours 2
   • For patients >75 years: Use fondaparinux with caution 2

4. Weight considerations:

   • For patients <50 kg: Use fondaparinux with caution 2
   • For morbidly obese patients: Consider institutional LMWH dosing algorithm 2

5. Mechanical prophylaxis:

   • Add intermittent pneumatic compression devices or elastic stockings intraoperatively 2
   • Ensure patient remains warm and well-hydrated 2
   • Use mechanical methods when pharmacological prophylaxis is contraindicated due to active bleeding, coagulopathy, or hemodynamic instability 2

Monitoring and Follow-up

1. No routine monitoring is required for LMWH prophylaxis 5
2. For patients with renal dysfunction, consider anti-Xa level monitoring to improve efficacy without increasing bleeding risk 2
3. Early mobilization should be encouraged as an additional preventive measure 2

By implementing this evidence-based approach to DVT prophylaxis in hip fracture patients, you can significantly reduce the risk of VTE while minimizing bleeding complications and improving overall mortality outcomes.