Deep Vein Thrombosis

A swollen, warm calf after surgery might seem minor — but the clot hiding in that deep vein can silently migrate and become a life-threatening pulmonary embolism within hours.

Deep vein thrombosis (DVT) is a blood clot forming in a deep vein, most commonly in the lower extremities. Virchow's triad drives risk: venous stasis (immobility, surgery, long flights), endothelial injury (trauma, IV catheters, surgery), and hypercoagulability (pregnancy, oral contraceptives, cancer, clotting disorders). Classic assessment findings include unilateral leg swelling, warmth, redness, and calf pain — especially pain with dorsiflexion (positive Homans' sign, though its sensitivity is poor and it is no longer recommended as a reliable screening tool). Measure calf circumference bilaterally; a difference of more than 2 cm is significant. Diagnosis is confirmed by duplex ultrasound; D-dimer is a useful screening lab but elevates in many conditions. Initial treatment is anticoagulation — typically heparin (IV unfractionated or subcutaneous LMWH like enoxaparin), bridging to warfarin or using a direct oral anticoagulant. Nursing priorities include bed rest during acute phase per facility protocol, elevating the affected extremity, applying compression stockings to the unaffected leg, never massaging the affected leg, and monitoring for signs of bleeding from anticoagulation therapy.

Key Distinctions

Don't confuse DVT (venous — swelling, warmth, edema, dull ache) with peripheral arterial disease (arterial — pallor, coolness, absent pulses, sharp pain with activity). Students mix up Homans' sign awareness: know it exists for NCLEX recall but recognize it is unreliable due to poor sensitivity and specificity. DVT is the clot formation and assessment story; pulmonary embolism is the complication — PE management belongs in its sibling atom.

Clinical Pearl

Never massage a DVT leg — you're squeezing the trigger on a clot gun aimed straight at the lungs.