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DVT DVT Current Concepts Current Concepts Dr Saeed Al-Shomimi King Fahad Hospital of University Khobar – Saudi Arabia 2005

DVT Current Concept

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  • 1.DVT Current Concepts Dr Saeed Al-Shomimi King Fahad Hospital of University Khobar Saudi Arabia 2005

2. Venous Thromboembolism Stasis Activation of Coagulation Vessel Damage Virchow's Triad 3. Etiology 4. FREQUENTLY ENCOUNTERED

  • Prolonged fever + recumbency
  • Lengthy major surgery
  • Orthopaedic / Urologic
  • Massive trauma
  • Pregnancy
  • Long standing v.vs
  • hepatitis

5. ETIOLOGY Obscure Zones 6.

  • Anesthesia
    • general anesthesia have a5Xincreased risk of DVT compared with patients receiving epidural anesthesia for the same surgical procedure.

7.

  • Blood surface antigens
    • TypeAblood is associated with lower levels of antithrombin III and higher levels of factor VIII than type O blood.
    • Women of reproductive age with type A blood are4 timesas likely to develop DVT.
    • This association of risk with blood type A does not extend to older men or to women past reproductive age

8.

  • Cancer
    • Malignancy is an important risk factor for DVT, and spontaneous DVT without an obvious cause is an important marker for possible occult malignancy.
    • In38%of cases of concomitant cancer and DVT, the DVT is detected first.

9.

    • The relative risk for cancer is19 timeshigher for patients younger than 50 years who have had DVT than for those without a history of DVT.
    • 16%of patients with angiographically proven PE are diagnosed with cancer within 2 years.

10.

  • Strokes and neurotrauma
    • common after stroke or neurological trauma.
    • Without prophylaxis,halfthe patients develop acute DVT within 5 days following a stroke.
    • Head trauma may cause disseminated intravascular coagulation, and DVT.

11.

    • 40%of postoperative neurosurgical patients develop DVT.
    • Stroke patients with a single paretic leg develop DVT in60%of the paralyzed legs but in only7%of the nonparalyzed ones.

12.

  • Chemotherapy
    • Many types of chemotherapy increase the risk of DVT and PE
      • the levels of circulating anticoagulants such as antithrombin III or protein C or S
      • procoagulants such as von Willebrand factor
      • depress fibrinolytic activity .

13.

  • Coagulopathy
    • Protein C
    • Protein S
    • Antithrombin III
    • 15%of the cases of DVT

14.

  • Heart disease
    • Acute MI and CHF increase the likelihood of DVT and PE, independent of bed rest or immobilization.
    • Patients with acute MI who are not receiving anticoagulation have a 26-38% rate of DVT.

15.

  • Inflammatory bowel disease
    • Patients with ulcerative colitis or Crohn disease are at increased risk for DVT and PE because of increased fibrinogen, factor VIII, and platelet activity and depressed levels of antithrombin III and alpha2-macroglobulin.

16.

  • Prior DVT
    • Patients with a prior episode of DVT are5times more likely to develop new DVT compared with patients with no prior episodes of DVT.
    • Prior DVT increases the risk of new postoperative DVT from26% to 68%.
    • A history of prior clinically apparent PE increases the risk of new postoperative DVT to nearly100%.

17. Autoimmune Vasculitis

  • Behcets disease
  • Lupus antibodies
  • Anticardiolipin AB
  • Antiphospholipid AB
  • ASMC AB

Especially in young with no apparent cause 18. INVESTIGATIONS 19. LAB

  • PT ,PTT , INR
  • ESR
  • D - dimer
  • ABG
  • Protein C , S Antithrombin III

20. RADIOLOGY

  • ULTRASOUND (Duplex)
  • VENOGRAPHY (rarely used)
  • MRV
  • ventilation - perfusion scanning ( for PE )
  • Nuclear venography

21. 22. 23. 24. MANAGEMENT 25. GENERAL MEASURES

  • 1- Complete bed rest
  • 2-The affected extremity should be elevated above the level of the heart until the oedema and tenderness subside .

26.

  • Anticoagulants
  • Thrombolytics
  • Prophylaxis

27. I-Anticoagulants

  • Anticoagulants prevent thrombous propagation & allow endogenous lytic system to operate.
  • Aim :prevention of pulmonary embolism , since in the early stages the thrombus maybe loose & poorly adherent to the vessel wall.

28. Contraindication

  • 1-recent surgery, especially to eye or CNS.
  • 2-Pre_existing hemorrhagic state
  • e.g. Liver ds
  • Renal Failure
  • Hemophilia
  • Thrombocytopenia
  • 3-Pre_existing structural lesions
  • e.g. Peptic Ulcer
  • 4-Recent cerebral hemorrhage.
  • 5-Uncontrolled HPN.

29. 1-Heparin

  • Mech. Of action
  • Standard Heparin (SH)
    • produces its anticoagulant effect by potentiating the activity of anti-thrombin which will inhibit procoagulant enzymatic activity of factors IIa ,VIIa ,IXa ,Xa ,XIa.
  • LMWH
    • augment anti-thrombin activity against factor Xa.

30. Advantages of LMWH over SH

  • 1-LMWH has a high bioavailability after SC injection so its given either as a fixed or weight-related dose .Therefore ,The plasma LMWH level does not need to be measured.
  • 2-The incidence of thrombocytopenia is less with LMWH than SH.

31.

  • 3-LMWH is reported to be as effective as or better than SH in preventing extension or recurrence of venous thrombosis.

32. Route of Admn. & Dose

  • Heparin(IV) as an initial bolus of 7500 to 10,000 IU followed by a continuous infusion of 1000 to 1500 IU/h.
  • The rate of heparin infusion should be adjusted so that the active aPTT is approximately twice the control value.

33.

  • S/Ein less than 5% of patients ,heparin therapy may cause thrombocytopenia. Infrequently ,these pt develop arterial thrombosis & Ischemia

34. 2-WARFARIN

  • Mech. Of action ..
  • Warfarin inhibit vit K-dependant carboxylation of factors II ,VII ,IX ,X in the liver.
  • Warfarin is administered during the 1 stwk of treatment with heparin &maybe started as early as the 1 stday of heparin treatment if the aPTT is therapeutic.

35.

  • Why to overlap Heparin ttt with oral anticoagulant therapy??
  • This because of the delayed effect of warfarin.
  • SOOverlap is important for at least 4-5 days
  • Dose of warfarin should be adjusted to maintain the thrombin time at anINR of 2-3

36. Duration of anti-coagulant therapy

  • 1 stattack3 M
  • 2 ndattack1 year
  • 3 rdattackLife

37. BUTWhat if treatment with anti-coagulant is contraindicated???

  • IVC filter.

38. II-Thrombolytics

          • Streptokinase
          • Urokinase
          • Tissue Plasminogen Activator

39.

  • There is no evidence that thrombolytic therapy is more effective than anti-coagulants in preventing pulmonary embolism!!
  • HOWEVER early administration of thrombolytic drugs may accelerate clot lysis .

40. III-Prophylaxis

  • ALL PATIENTS ADMITTED TO HOSPITAL SHOULD BE ASSESSED FOR THEIR RISK OF VENOUS THROMBOSIS .

41.

  • Mechanical:
  • - early mobilization
  • -leg raising.
  • - graduated compression (TED) stocking.
  • Drugs (anti-coagulants).

42.

  • Hip or knee surgery
  • Major abdominal or pelvic surgery for malignancy or with history of DVT
  • Major surgery in patient>40 years or with other risk factor
  • Major medical illness
  • e.g. heart failure
  • chest infection
  • malignancy
  • inflammatory bowel disease

High risk of DVT Moderate risk of DVT 43.