Acute Deep Venous Thrombus

Risk Factors

• Strong risk factors (OR > 10)

  • Fracture (hip or leg)

  • Hip or knee replacement

  • Major general surgery

  • Major trauma

  • Spinal cord injury

• Moderate risk factors (OR 2-9)

  • Arthroscopic knee surgery

  • Central venous lines

  • Chemotherapy

  • Congestive heart or respiratory failure

  • Hormone replacement therapy

  • Malignancy

  • Oral contraceptive therapy

  • Paralytic stroke

  • Pregnancy (postpartum) 

  • Previous venous thromboembolism

  • Thrombophilia

• Weak risk factors (OR < 2)

  • Bed rest > 3 days

  • Immobility due to sitting (e.g., prolonged car or air travel)

  • Increasing age

  • Laparoscopic surgery

  • Obesity

  • Pregnancy (antepartum)

  • Varicose veins

Mechanical Prophylaxis

• Elastic compression stockings work by flow augmentation and decrease DVT rates from 26% to 13%

• Sequential compression devices (SCDs) also work by flow augmentation as well as stimulating the release of t-PA, prostacyclin, vWF, & TFPI; they have been shown to decrease DVT rates from 60 to 30 per 1000 in high-risk patients

• Foot compression devices work the same as SCDs

• Early ambulation, while encouraged, has never been objectively proven to reduce VTE rates

Pharmacologic Prophylaxis

• Pharmacologic prophylaxis with LMWHs, UFH, or fondaparinux have all been shown to be superior to placebo or mechanical prophylaxis

• LMWH is considered marginally superior based on meta-analyses, particularly in high-risk populations (e.g., stroke, critically ill, elderly)

• Aspirin and warfarin, while studied, should not be used as primary agents for VTE PPX

• Lovenox 40 mg subcutaneously once daily for CrCl > 30

• Heparin 5000 units subcutaneously BID to TID

  • Meta-analyses are mixed on