DEEP VEIN THROMBOSIS

Definitions Deep-vein thrombosis (also known as deep-venous thrombosis or DVT) is the formation of a blood clot ("thrombus") in a deep vein. Pulmonary embolism (PE) is a condition that occurs when an artery in your lung becomes blocked.

Thrombosis

Virchow’s Triad It is the result of 1 of 3 factors known as Virchow’s Triad. Endothelial damage Venous blood stasis Hypercoagulability

Signs & Symptoms Pain in the leg Tenderness in the calf (one of the most important signs) Leg tenderness Swelling of the leg Increased warmth of the leg Redness in the leg Bluish skin discoloration

DIAGNOSIS OF DVT Clinical examination Investigations

CLINICAL EXAMINATION Homan’s sign Moses’ sign Phlegmasia alba dolens (white leg) Phlegmasia cerulea dolens (blue leg)

Diagnosis of DVT Duplex Ultra sonography - Projected sound waves bounce off structures in the leg and create images that reveal abnormalities. The addition of color Doppler imaging improves accuracy. Venography – An x-ray of leg and pelvis will show the calf and thigh veins and reveal any blockages.

places in the leg to identify possible blockages. Diagnosis of DVT MRI - particularly effective in diagnosing DVT in the pelvis, and as effective as venography in diagnosing DVT in the thigh. Cuff-impedance plethysmography - uses blood pressure checks at different places in the leg to identify possible blockages.

Potential Complications Pulmonary emboli- most serious complication of DVT Chronic venous insufficiency - Long-term DVT can degenerate the venous valves. Post- phlebotic syndrome - long-term complication of DVT which occurs due to damage and scarring to the veins and is characterized by swelling, discomfort and skin pigmentation in the affected area. Of a dvt

DVT Risk Factors Risk Factor= 1 Point Risk Factor= 2 Points Age 41-60 years Bedrest COPD CHF (<1 month) Acute MI Pneumonia (< I month) Sepsis (<month) Inflammatory Bowel Disease Minor surgery planned Hx of prior major surgery Obesity (BMI>25) Swollen legs Pregnancy Oral Contraceptives Age 60-74 years Athroscopic surgery Laparoscopic surgey Malignancy (present or history) Major surgery (>45 Minutes) Patient confined to bed (>72 hours) Immobilizing plaster cast(<1month) Central Venous Access Infection Nephrotic Syndrome

DVT Risk Factors Risk Factor= 3 Point Risk Factor =5 Points Age >75 years Major surgery(>3 hours) Hx of DVT/PE Family hx of Thrombosis Heparin-induced thrombocytopenia Thrombophilia Hx of clotting disorder Elective major lower extremity arthroplasty Hip, pelvis, or leg fracture(<1 month) Stroke(< 1 month) Acute spinal cord injury (paralysis<1 month)

RISK LEVEL FOR DVT….. Low Risk- DVT score 1 Moderate Risk- DVT score 2 High Risk- DVT score 3-4 Highest Risk- DVT score 5 or more

Prevention DVT/PE Pharmacologic Non-pharmacologic

Prevention: Non-pharmacologic Mechanical methods: Used in combination with drug therapy or as monotherapy in those with lower risk or contraindications to anticoagulation prophylaxis Includes aggressive mobilization, foot pumps, intermittent pneumatic leg pumps, graduated compression stockings These methods MUST be used for most of the day (>21 hours) to be effective

Prevention: Pharmacologic Unfractionated Heparin Low Molecular Weight Heparin (LMWH) daltaparin (Fragmin), enoxaparin (Lovenox) Factor Xa Inhibitor fondaparinux (Arixtra) Warfarin (Coumadin)

Contraindications to Pharmacological Prophylaxis Active GI bleed Recent hemorrhagic stroke or hemorrhage Previous hypersensitivity or significant drug-specific ADR Platelet count <100 X 109/L (varies) Neurosurgical Procedure within last 30 days Varies between institutions, physicians, and particular patient risk/benefit considerations

Unfractionated Heparin Indications: Prophylaxis and treatment of thromboembolic disorders Prophylactic Dose: 5,000 Units SQ q8hrs Monitoring: PTT, Plt, Hgb, Hct, bleeding

Unfractionated Heparin Complications: hemorrhage (most common), thrombocytopenia, hyper-sensitivity Advantages: Cost, DVT prophylaxis of choice in pregnancy

Warfarin (Coumadin) Indication: Treatment of venous thrombosis, pulmonary embolis, and thromboembolic disorder Not generally used for DVT/PE prophylaxis (except long term prevention, such as patients with valve replacements) due to delayed onset of action and higher risk of bleeding complications Dose: Typical starting dose is 2.5 to 5 mg Use “bridge therapy” (LMWH or heparin + warfarin) when immediate anticoagulation is warranted

Bridge Therapy The anticoagulant effects of warfarin (Coumadin) are not immediate It takes several days (~ 5 days) to a week to deplete existing Vitamin K dependent clotting factors in the body During this lag time, the patient must be protected against DVT/PE with Heparin, enoxaparin (Lovenox), daltaparin (Fragmin) or fondaparinux (Arixtra) until the therapeutic INR is achieved

Bridge Therapy Concurrent therapy with warfarin (Coumadin) MUST be continued for a minimum of 5 days, AND 2 consecutive INR values must be seen before the discontinuation of LMWH or heparin may occur