Stroke patients with a single paretic leg develop DVT in60%of
the paralyzed legs but in only7%of the nonparalyzed ones.
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 .
15%of the cases of DVT
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.
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.
Patients with a prior episode of DVT are5times more likely to
develop new DVT compared with patients with no prior episodes of
Prior DVT increases the risk of new postoperative DVT from26%
A history of prior clinically apparent PE increases the risk of
new postoperative DVT to nearly100%.
17. Autoimmune Vasculitis
Especially in young with no apparent cause 18. INVESTIGATIONS
PT ,PTT , INR
D - dimer
Protein C , S Antithrombin III
VENOGRAPHY (rarely used)
ventilation - perfusion scanning ( for PE )
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 .
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
1-recent surgery, especially to eye or CNS.
2-Pre_existing hemorrhagic state
e.g. Liver ds
3-Pre_existing structural lesions
e.g. Peptic Ulcer
4-Recent cerebral hemorrhage.
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.
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
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.
S/Ein less than 5% of patients ,heparin therapy may cause
thrombocytopenia. Infrequently ,these pt develop arterial
thrombosis & Ischemia
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.
Why to overlap Heparin ttt with oral anticoagulant
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
37. BUTWhat if treatment with anti-coagulant is
Tissue Plasminogen Activator
There is no evidence that thrombolytic therapy is more
effective than anti-coagulants in preventing pulmonary
HOWEVER early administration of thrombolytic drugs may
accelerate clot lysis .
ALL PATIENTS ADMITTED TO HOSPITAL SHOULD BE ASSESSED FOR THEIR
RISK OF VENOUS THROMBOSIS .
- early mobilization
- graduated compression (TED) stocking.
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