Which statement correctly describes a valid approach to pharmacologic prophylaxis for DVT?

• A. Mechanical: compression stockings
• B. Mechanical: intermittent pneumatic compression
• C. Pharmacologic: high-dose heparin
• D. Pharmacologic: low-dose heparin or LMWH, unless contraindicated

Answer: (D)

Pharmacologic prevention relies on mild anticoagulation to curb clot formation without needing full therapeutic anticoagulation. Low-dose unfractionated heparin or low-molecular-weight heparin given by subcutaneous injection reduces the risk of DVT by inhibiting key steps in the coagulation cascade. This approach is appropriate when there isn’t a significant bleeding risk or other contraindications. Using high-dose heparin would raise bleeding risk without providing additional benefit for prevention, so it isn’t used for prophylaxis. Mechanical methods like compression devices are valuable alternatives or adjuncts when anticoagulation is not possible, but the stated pharmacologic option—low-dose heparin or LMWH, unless contraindicated—best describes a valid pharmacologic strategy.