Deep vein thrombosis (DVT)

• Blood clot
• Deep vein thrombophlebitis
• Venous thrombosis
• Venous thromboembolism

• 453.4 Acute venous embolism and thrombosis of deep vessels of the lower extremity
• 453.5 Chronic venous embolism and thrombosis of deep vessels of lower extremity

• I74.9 Embolism and thrombosis of unspecified artery
• I82.4 Acute embolism and thrombosis of deep veins of lower extremity
• I82.90 Acute embolism and thrombosis of unspecified vein

• Pattern 6A: Primary Prevention/Risk Reduction for Cardiovascular/Pulmonary Disorders1

Description

• Clot formation and acute inflammation of deep vein
• Associated with Virchow’s triad:2
  • Decreased rate of blood flow (venous stasis)
  • Damage to blood vessel
  • Hypercoagulation
• Most commonly occurs in lower extremity (LE)
• Pulmonary embolism (PE) occurs when blood clot breaks off and settles in lung

Essentials of Diagnosis

• Clinical decision rule for outpatients suspected of having a proximal DVT3
• History: family history, recent trauma, cancer, oral contraceptives
• Subjective report of pain
• Visual examination
• Reproduction of symptoms with dorsiflexion of the ankle (Homan’s sign) and palpation2
• Diagnostic ultrasound of affected veins
• Ankle-brachial index
• D-dimer test
• Well’s score or criteria: possible scores range from −2 to 9
  • Active cancer (treatment within last 6 months or palliative): +1 point
  • Calf swelling ≥ 3 cm compared to asymptomatic calf (measured 10 cm below tibial tuberosity): +1 point
  • Swollen unilateral superficial veins (non-varicose) in symptomatic leg: +1 point
  • Unilateral pitting edema in symptomatic leg: +1 point
  • Previous documented DVT: +1 point
  • Swelling of entire leg: +1 point
  • Localized tenderness along deep venous system: +1 point
  • Paralysis, paresis, or recent cast immobilization of lower extremities: +1 point
  • Recently bedridden ≥ 3 days, or major surgery requiring regional or general anesthetic in past 12 weeks: +1 point
  • Alternative diagnosis equally or more likely: −2 points

General Considerations

• DVT may result in a PE, a life-threatening medical emergency
• DVT and PE are the two manifestations of venous thromboembolism (VTE)
• Late complication of DVT is post-thrombotic syndrome: results in limb edema, pain, swelling
• Virchow’s triad is primary mechanism of DVT onset2

Demographics

• Individuals subjected to prolonged hospitalization or immobilization (orthopedic cast, long airplane flight, bed rest)
• Prevalence increases with age
• Women at increased risk while taking oral contraceptives and during pregnancy

Signs and Symptoms

• May be asymptomatic in early stage
• Sudden unilateral leg symptoms including:
  • Edema
  • Swelling, inflammation
  • Skin discoloration, redness
  • Warmth
  • Tenderness
• Low-grade fever
• Tachycardia
• Pain exacerbated with exercise but still present at rest

Functional Implications

• If DVT suspected, initiate therapeutic interventions
• Pulmonary embolism
• Cerebrovascular accident
• Death

Possible Contributing Causes

• Family history of DVT
• Older age
• Protein C or S deficiencies
• Oncology treatment
• Recent surgery
• Post-operative4
• Post-pregnancy up to 6 weeks
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