Deep vein thrombosis (DVT) is the development of blood clots in the deep veins, usually in the legs or pelvis. Risk factors include immobilization, surgery, cancer, older age, and inherited clotting disorders. DVT is typically diagnosed with ultrasound or venography and treated with blood thinners like low molecular weight heparin, fondaparinux, or warfarin to prevent pulmonary embolism. Long term anticoagulation is often needed due to the risk of recurrence. Prevention focuses on early mobilization and compression stockings or drugs for high risk patients.

1.  What is a Deep Vein Thrombosis?
 8. Deep Vein Thrombosis
Deep vein thrombosis (DVT) is the development of thrombi in the deep veins of the extremities
or pelvis.
DVT
Deep venous thrombophlebitis
 9. EPIDEMIOLOGY & DEMOGRAPHICS
Annual incidence in urban population is 1.6 cases/1000 persons.
The risk of recurrent thromboembolism is higher among men than women
Annual incidence is 0.1% in white population
 10. ETIOLOGY
The etiology is often multifactorial (prolonged stasis, coagulation abnormalities, vessel wall
trauma).
The following are risk factors for DVT:
• Prolonged immobilization (≥3 days)
• Postoperative state
• Trauma to pelvis and lower extremities
• Birth control pills, high-dose estrogen therapy;
 11. Etiology
 Visceral cancer (lung, pancreas, alimentary tract, GU tract)
 12. Age >60 yr.
 13. History of thromboembolic disease
 14. Hematologic disorders (e.g., antithrombin III deficiency, protein C deficiency, protein
S deficiency, heparin cofactor II deficiency, sticky platelet syndrome, G20210A
prothrombin mutation, lupus anticoagulant, dysfibrinogenemias, anticardiolipin antibody,
hyperhomocysteinemia, concurrent homocystinuria, high levels of factors VIII, XI, and
factor V Leiden mutation)
 Etiology
Pregnancy and early puerperium
Obesity, CHF
Surgery requiring >30 min of anesthesia
Gynecologic surgery (particularly gynecologic cancer surgery)
 15. Etiology
Recent travel (within 2 wk, lasting >6 hr)
Smoking and abdominal obesity
Central venous catheter or pacemaker insertion
Superficial vein thrombosis, varicose veins

2.  16. Diagnosis
Symptoms: The patient may complain of leg swelling, pain, or warmth.
Signs: The patient’s superficial veins may be dilated, and a “palpable cord” may be felt in the
affected leg. The patient may experience pain in the back of the knee when the examiner
dorsiflexes the foot of the affected leg.
 17. Diagnosis
Diagnostic Tests
Duplex ultrasonography
Venography (aka phlebography)
“Gold Standard” for DVT diagnosis
 18. Diagnosis
Laboratory Tests
Serum Concentrations of D-dimer, a by-product of thrombin generation, usually are elevated.
The patient may have an elevated erythrocyte sedimentation rate (ESR) and White Blood Cell
(WBC) count.
 19.
 20. ACUTE GENERAL Pharmacaotherapy
 Traditional treatment consists of IV unfractionated heparin for 4 to 7 days followed by
warfarin therapy.
 21. Low–molecular-weight heparin enoxaparin (Lovenox) is also effective for initial
management of DVT and allows outpatient treatment.
 22. Recommended dose is 1 mg/kg q12h SC and continued for a minimum of 5 days and
until a therapeutic INR (2-3) has been achieved with warfarin
 Dosages for lmwh and ufh
 Enoxaparin (Lovenox) 1mg/kg every 12 hours or 1.5mg/kg every 24 hours
 23. Dalteparin (Fragmin) 100units/kg every 12 hours or 200units/kg every 24 hours
 24. Tinzaparin (Innohep) 175units/kg every 24 hours
 25. UFH: Loading dose of 80 to 100units/kg (max. 10,000units) followed by a continuous
IV infusion at an initial rate of 17 to 20 units/kg/h (max. 2300 units/h)
 Advantages of low molecular weight heparin over unfractionatedheparin
 More reliable dose-response relation
 26. No need for laboratorymonitoring with the activated partial thromboplastin time
(althoughcan be monitored with anti-Xa activity)
 27. No need for dose adjustments
 28. Lowerincidence of thrombocytopenia
 29. No excess bleeding
 30. Can be administeredby the patient at home
 31. Economically advantageous

3.  Pearls and Considerations
When using heparin, there is a risk of heparin-induced thrombocytopenia (with unfractionated
more so than with LMWH). Platelet count should be obtained initially and repeated every 3 days
while on heparin.
 32. Acute General Pharmacotherapy
Once-daily fondaparinux (Arixtra), a synthetic analog of heparin, is also as effective and safe as
twice daily enoxaparin in the initial treatment of patients with symptomatic DVT.
Selective inhibitor of factor Xa
Dose: 7.5mg SC daily
 33. Acute General Pharmacotherapy
Warfarin therapy should be initiated when appropriate (usually within 72 hr of initiation of
heparin).
Interferes with vitamin K dependent factors (II, VII, IX, X)
Interactions: Ethanol, Vitamin E, Cranberry juice
Pregnancy category X
 34. ACUTE GENERAL pharmacotherapy
Low–molecular-weight heparin, when used, should be overlapped with warfarin for at least 5
days and until the INR has exceeded 2 for 2 consecutive days.
 35. ACUTE GENERAL pharmacotherapy
Exclusions from outpatient treatment of DVT include patients with potential high complication
risk (e.g., Hemoglobin <7, platelet count <75,000, guaiac-positive stool, recent CVA or
noncutaneous surgery, noncompliance).
 36. Acute General Pharmacotherapy
Insertion of an inferior vena cava filter to prevent pulmonary embolism is recommended in
patients with contraindications to anticoagulation
 37.
 38. Acute General Pharmacotherapy
 Thrombolytic therapy (streptokinase) can be used in rare cases (unless contraindicated) in
patients with extensive iliofemoral venous thrombosis and a low risk of bleeding
 39. Not generally used unless there is a massive thrombus or limb salvage is necessary
(due to gangrene)
 40. Has not been shown to decrease morbidity or mortality in PE
 CHRONIC Pharmacotherapy
Conventional- intensity warfarin therapy is more effective than low-intensity warfarin therapy for
the long term prevention of recurrent DVT.
The low-intensity warfarin regimen does not reduce the risk of clinically important bleeding.
 41. Chronic Pharmacotherapy

4.  The optimal duration of anticoagulant therapy varies with the cause of DVT and the
patient's risk factors:
 42. 1. Therapy for 3-6 mo. is generally satisfactory in patients with reversible risk
factors (low-risk group).
 43. 2. Anticoagulation for at least 6 mo. is recommended for patients with idiopathic
venous thrombosis or medical risk factors for DVT (intermediate-risk group).
 44. 3. Indefinite anticoagulation is necessary in patients with DVT associated with
active cancer; long-term anticoagulation is also indicated in patients with inherited
thrombophilia (e.g., deficiency of protein C or S antibody), antiphospholipid, and those
with recurrent episodes of idiopathic DVT (high-risk group).
 Chronic Pharmacotherapy
Measurement of d-dimer after withdrawal of oral anticoagulation may be useful to estimate the
risk of recurrence. Patients with a first spontaneous DVT and a d-dimer level <250 μg/mL
after withdrawal of oral anticoagulation have a low risk of DVT recurrence.
 45. Pearls and Considerations
Approximately 20%-50% of patients with DVT develop postthrombotic syndrome characterized
by leg edema, pain, venous ectasia, skin induration, and ulceration.
 46. Pearls and Considerations
Exercise following DVT is reasonable because it improves flexibility of the affected leg and does
not increase symptoms in patients with postthrombotic syndrome
 47. Prevention is better than treatment
 Mechanical Methods
 48. Early mobilization as soon as possible after surgery
 49. Graded compression stocking
 50. Pharmacological Methods
 51. UFH
 52. LMWH
 53. Fondaparinux
 54. Warfarin
 Pearls and Considerations
 Prophylaxis of DVT is recommended in all patients at risk (e.g., low–molecular-weight
heparin [enoxaparin 30 mg SC bid] after major trauma, post surgery of hip and knee;
enoxaparin 40 mg SC qd post–abdominal surgery in patients with moderate to high DVT
risk; gradient elastic stockings alone or in combination with intermittent pneumatic
compression [IPC] boots following neurosurgery).
 Pearls and Considerations
Fondaparinux (Arixtra), a synthetic analog of heparin, can also be used for prevention of DVT
after hip fracture surgery, hip replacement, or knee replacement. Initial dose is 2.5 mg SC given

5. 6 to 8 hr postoperatively and continued daily. Its bleeding risk is similar to enoxaparin; however,
it is more effective in preventing DVT
 55. Case presentation
 Subjective:
 56. Calf pain and swelling
 57. Risk Factors: Smoking, SERM use, Previous DVT
 58. Objective:
 59. (+) Homan’s sign in right calf with no palpable cord
 60. Factor V Leiden Mutation – positive
 61. Venous compression Ultrasonography- RLE shows non compressibility of the right
posterior tibial vein with no color flow. Normal compressibility and flow demonstrated
within the right common femoral and iliac veins. LLE shows normal compression of the
deep venous system from the level of the common femoral vein to the popliteal vein
 Case presentation
Assessment:
Acute Deep vein thrombosis of the right posterior tibial vein requiring initiation of
anticoagulation. Venogram not necessary due to positive ultrasound results
 62. DVTs in and/or around the politeal vein are termed proximal
 63. Case presentation
Plan:
Treatment
Day 1-5:
Enoxaparin 122 U (1mg/kg) SC every 12 hours for 5 days
Warfarin 5mg by mouth daily
 64. Case presentation
Plan
Day 6
Discontinue LMWH
Patient is to continue on warfarin therapy for at least one year due to prior DVT
 65. REFERENCES
Anderson F.A. , Jr, Spencer F.A., Risk factors for venous thromboembolism. Circulation
(2003) 107 : pp 9-16
White R.H., The epidemiology of venous thromboembolism. Circulation (2003) 107 : pp I4-I8.
Antithrombotic Therapy for Venous Thromboembolic Disease The Seventh ACCP Conference
on Antithrombotic and Thrombolytic Therapy Chest - Volume 126, Issue 3 (September 2004)
Barrit DW, Jordan SC. Anticoagulant drugs in the treatment of pulmonary embolism: a
controlled trial. Lancet 1960; 1:1309–1312
Crowther MA, Ginsberg JB, Kearon C, et al. A randomized trial comparing 5-mg and 10-mg

6. warfarin loading doses. Arch Intern Med 1999; 159:46–48
Kernohan RJ, Todd C. Heparin therapy in thromboembolic disease. Lancet 1966; 1:621–623
Harrison L, Johnston M, Massicotte MP, et al. Comparison of 5-mg and 10-mg loading doses in
initiation of warfarin therapy. Ann Intern Med 1997; 126:133–136