Deep Vein Thrombosis

1. See Also
   1. Pulmonary Embolism
   2. DVT Prevention
   3. Deep Vein Thrombosis in Pregnancy
   4. Upper Extremity DVT
2. Epidemiology: Incidence Venous Thromboembolism
   1. General population: 0.1%
   2. Elderly: 1%
   3. Hospitalized patients: 15%
3. Risk Factors
   1. See Deep Vein Thrombosis Risk Factors (includes Recurrent Thromboembolism Risks)
   2. See Thrombophilia
4. Signs
   1. Clinical exam is unreliable for DVT
   2. Homans' Sign (no predictive value)
      1. Homans' Sign: Relaxed foot abnormally plantar flexed
      2. Pseudo-Homans': Pain on passive dorsiflexion of foot
   3. Other unreliable signs
      1. Tenderness
      2. Distal extremity edema
      3. Palpable cord
5. Diagnosis
   1. Step 1: Assess DVT Probability
      1. See Wells Clinical Prediction Rule for DVT
      2. If moderate to high probability, goto step 3
   2. Step 2: Low Probability for DVT
      1. Obtain D-Dimer
      2. Negative D-Dimer: Excludes DVT
      3. Positive D-Dimer: Lower Extremity Doppler ultrasound
         1. Negative ultrasound: Excludes DVT
         2. Positive ultrasound: Treat as DVT
   3. Step 3: Moderate to high Probability for DVT
      1. Obtain Lower Extremity Doppler ultrasound
      2. Negative Ultrasound: Obtain D-Dimer
         1. Negative D-Dimer: Excludes DVT
         2. Positive D-Dimer: Repeat ultrasound or venography
      3. Positive Ultrasound: Treat as DVT
   4. References
      1. Bockenstedt (2003) N Engl J Med 349:1203-4
6. Management: General
   1. See DVT in Pregnancy
   2. See Pulmonary Embolism Management
      1. Anticoagulation protocols are the same for DVT and PE
   3. Consider Thrombophilia work-up
      1. See Thrombophilia
      2. Reserve blood for tests prior to Anticoagulation
   4. Anticoagulation Protocol
      1. Anticoagulation in Thromboembolism
   5. Disposition
      1. Hospitalization and Heparin for high risk patients
      2. Consider home management with LMWH (see below)
   6. Local measures
      1. Minimize activity for first few days
      2. Elevate affected limb
      3. Apply heat to affected limb
      4. Graded elastic Compression stockings
         1. Reduce risk of postphlebitic syndrome
7. Management: Distal DVT (Calf-vein DVT)
   1. Treated now due to risks (not treated in past)
      1. Risk of propogation to proximal DVT is 20%
      2. Recurrs in 30% of untreated patients
      3. Post-thrombotic syndrome occurs in 20% if untreated
   2. Now Anticoagulation recommended for 6 to 12 weeks
      1. Initiate with LMWH and then to oral Warfarin
   3. If Anticoagulation contraindicated
      1. Repeat doppler ultrasound twice weekly for 2 weeks
      2. Monitor for proximal DVT
   4. Pinede (2001) Circulation 103:2453-60
8. Management: Anticoagulation
   1. See Anticoagulation in Thromboembolism
9. Management: Home Deep Vein Thrombosis Protocol
   1. Criteria for home management
      1. No massive Deep Vein Thrombosis
         1. No entire Leg Swelling, acrocyanosis or ischemia
         2. No DVT extension into iliofemoral vein or IVC
      2. No symptomatic Pulmonary Embolism
         1. Oxygen Saturation >95% on room air
      3. No significant bleeding risks on anticoagulants
         1. Active bleeding or bleeding in last 4 weeks
         2. Recent surgery or trauma
         3. Platelet Count <100, INR >1.4 or PTT >40 sec
         4. Metastatic disease involving liver or brain
      4. No significant comorbidities
         1. Impaired cognition or mobility
         2. Pain requiring parenteral Narcotics
      5. References
         1. Douketis (2005) Can Fam Physician 51:217-23
   2. Efficacy
      1. Safe and effective management of proximal DVT
      2. Spyropoulos (2002) Chest 122:108-14
   3. Review Contraindications
      1. Use only in otherwise low risk patients
      2. See Low Molecular Weight Heparin for contraindication
   4. Patient Education
      1. Demonstrate self-administered Subcutaneous Injections
      2. Review sterile technique
      3. Review risks of bleeding and infection
      4. Emphasize precautions against trauma
   5. Consider home health referral
   6. Anticoagulation
      1. See Anticoagulation in Thromboembolism
10. Management: Intervention Radiology directed Thrombolysis (with benefit)
    1. Indication: Ileofemoral thrombus
       1. Ileofemoral DVT is high risk of comorbidity
       2. Post-thrombotic syndrome: >50%
       3. Venous Claudication at 5 years in nearly half of patients
    2. Efficacy data
       1. Normal vein after Heparin: 0%
       2. Normal vein after Catheter Thrombolysis: 45%
       3. Decreases risk of long term Venous Insufficiency and post-phlebitic syndrome
       4. Prevents stasis ulcers
       5. Best outcome if performed early (within 2 weeks)
       6. Poor efficacy if prior Deep Vein Thrombosis
       7. Some studies question long-term benefit
    3. References
       1. (2009) J Thromb Haemost 7:1268-75
11. Complications
    1. Pulmonary Embolism
    2. Post-thrombotic syndrome (postphlebitic syndrome)
       1. Reduced with below knee graded Compression stockings
       2. Prandoni (2004) Ann Intern Med 141:249-56
12. Precautions
    1. Idiopathic DVT associated with undiagnosed malignancy
       1. Relative Risk of malignancy diagnosis in 2 years: 3
       2. Oudega (2006) Brit J Gen Pract 56:693-6
13. Prevention
    1. See DVT Prevention
    2. See DVT Prophylaxis
    3. See DVT Prevention in Travelers
14. References
    1. Feied in Marx (2002) Rosen's Emergency Med, p. 1210-33
    2. AbuRahma (2001) Ann Surg 233(6):752
    3. Forster (2001) Chest 119(2):572-9
    4. Hull (2000) Arch Intern Med 160:229-36
    5. Hyers (2001) Chest 119:176S-93S
    6. Lensing (1999) Lancet 253:479-85
    7. Merli (2001) Ann Intern Med 134:191-202
    8. Ramzi (2004) Am Fam Physician 69:2841-8
    9. Wells (2001) Thromb Haemost 86(1):499-508