Which option correctly identifies a pharmacologic strategy for DVT prophylaxis?

• A. Intermittent pneumatic compression
• B. Compression stockings
• C. Low-dose heparin or LMWH, unless contraindicated
• D. Elevation of legs while immobile

Answer: (C)

Understanding how to prevent DVT involves distinguishing strategies that affect the coagulation process from those that don’t. A pharmacologic approach uses medications that interfere with clot formation. The best example here is giving a low-dose anticoagulant, such as heparin or low-molecular-weight heparin, by subcutaneous injection to patients at risk of DVT, unless there’s a reason not to because of bleeding risk or other contraindications. Heparin works by boosting antithrombin III to inhibit thrombin and factor Xa, while LMWH targets factor Xa more predictably, both reducing the likelihood of new clots forming during periods of immobility or after surgery.

The other options are mechanical or positional measures. Intermittent pneumatic compression and compression stockings help prevent DVT by promoting venous return and reducing stasis, but they do not affect the coagulation system. Elevating the legs is a supportive measure to lessen venous pooling, not a pharmacologic method.