Sandbox Rim

Overview

Venous thromboembolism (VTE) consists of deep vein thrombosis (DVT), pulmonary embolism (PE), or both. The risk factors for VTE are a constellation of predisposing conditions which stem from the three principles of Virchow's triad: stasis of the blood flow, damage to the vascular endothelial cells, and hypercoagulability. The risk factors for VTE can be categorized as temporary, modifiable and non-modifiable. Venous thrombosis also shares risk factors with cardiac thrombosis, such as obesity, hypertension and smoking.

Risk Factors

Shown below is a list of predisposing factors to VTE.

Strong risk factors	Moderate risk factors	Weak risk factors
❑ Bone fracture (hip or leg) ❑ Hip replacement surgery ❑ Knee replacement surgery ❑ Major general surgery ❑ Significant trauma ❑ Spinal cord injury	❑ Athroscopic knee surgery ❑ Central venous lines ❑ Chemotherapy ❑ Chronic heart failure ❑ Respiratory failure ❑ Hormone replacement therapy ❑ Cancer ❑ Oral contraceptive pills ❑ Stroke ❑ Pregnancy ❑ Postpartum ❑ Prior history of VTE ❑ Thrombophilia	❑ Bed rest for more than 3 days ❑ Prolonged car or air travel ❑ Advanced age ❑ Laparoscopic surgery ❑ Prepartum ❑ Obesity ❑ Varicose veins

Thrombophilia

Genetic Thrombophilia

• Factor V Leiden
• Prothrombin G20210A mutation
• Protein C deficiency
• protein S deficiency
• Antithrombin deficiency
• APC resistance
• Hyperhomocysteinemia

Acquired Thrombophilia

• Antiphospholipid syndrome
• Nephrotic syndrome
• Paroxysmal nocturnal hemoglobinuria