Deep vein thrombosis resident survival guide
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Vidit Bhargava, M.B.B.S [2]; Rim Halaby, M.D. [3]
Overview
Deep vein thrombosis (DVT) is the formation of a blood clot ("thrombus") in a deep vein.
Causes
Life Threatening Causes
Deep venous thrombosis can be a life-threatening condition if thromboembolism and subsequent pulmonary embolism occur, and it must be treated as such irrespective of the underlying cause.
Common Causes
FIRE: Focused Initial Rapid Evaluation
A Focused Initial Rapid Evaluation (FIRE) should be performed to identify patients in need of immediate intervention.
Complete Diagnostic Approach
Low Pretest Probability
| The patient has a low pre-test probability for DVT | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Proceed with one of the following: D-dimer test (1st line) Proximal US (2nd line) Whole leg US | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| D-dimer (1st line) | Proximal US (2nd line) | Whole leg US | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Negative | Positive | Negative | Positive | Negative | Positive | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Proceed with either: Proximal US OR Whole leg US | What is the location of the DVT? | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| DVT is excluded | Proximal US | Whole leg US | DVT is excluded | Treat DVT | DVT is excluded | Proximal DVT | Isolated distal DVT | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Negative | Positive | Negative | Positive | Treat DVT | Perform serial US OR Treat DVT | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| What is the location of the DVT? | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| DVT is excluded | Treat DVT | DVT is excluded | Proximal DVT | Isolated distal DVT | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Treat DVT | Perform serial US OR Treat DVT | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Moderate Pretest Probability
| The patient has a moderate pre-test probability of DVT | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Proceed with one of the following: D-dimer test | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| D-dimer test | Proximal US | Whole leg US | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Negative | Positive | Negative | Positive | Negative | Positive | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Proceed with either:Proximal US OR Whole led US | Repeat proximal US OR Order D-dimer | Treat DVT | DVT is excluded | Where is the location of the DVT? | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| DVT is excluded | Proximal US | Whole leg US | Repeat proximal US within 1 week | Order D-dimer | Proximal DVT | Isolated distal DVT | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Negative | Positive | Negative | Positive | Negative | Positive | Negative | Positive | Treat DVT | Perform serial US OR Treat DVT | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Repeat proximal US within 1 week | Treat DVT | DVT is excluded | What is the location of the DVT? | DVT is excluded | Treat DVT | DVT is excluded | Repeat proximal US within 1 week | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Negative | Positive | Proximal DVT | Isolated distal DVT | Negative | Positive | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| DVT is excluded | Treat DVT | Treat DVT | Perform serial US OR Treat DVT | Treat DVT | Perform serial US OR Treat DVT | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
High Pretest Probability
Long Term Treatment
Shown below is the long term treatment for DVT. Note that not all patients with isolated distal DVT are started on anticoagulation, only those who are started require long term therapy with anticoagulation. Patients who are planned to receive long term therapy with anticoagulation should be assessed regularly for the risks vs benefits of anticoagulation therapy.[1]
| Is the DVT provoked or unprovoked? | |||||||||||||||||||||||||||||||||||||||||||
| Provoked | Unprovoked | ||||||||||||||||||||||||||||||||||||||||||
| What is the predisposing factor? | Is this the first or second episode? | ||||||||||||||||||||||||||||||||||||||||||
| Surgical OR <bt>Transient non surgical predisposing factor | Cancer | First episode | Second episode | ||||||||||||||||||||||||||||||||||||||||
| Anticoagulation therapy for 3 months | Extended anticoagulation therapy | Is the DVT proximal or distal? | What is the risk of bleeding? | ||||||||||||||||||||||||||||||||||||||||
| Proximal DVT | Isolated distal DVT | Low or moderate risk of bleeding | High risk of bleeding | ||||||||||||||||||||||||||||||||||||||||
| What is the risk of bleeding? | Anticoagulation therapy for 3 months (irrespective of the risk of bleeding) | Extended anticoagulation therapy | Anticoagulation therapy for 3 months | ||||||||||||||||||||||||||||||||||||||||
| Low or moderate | High | ||||||||||||||||||||||||||||||||||||||||||
| Extended anticoagulation therapy | Anticoagulation therapy for 3 months | ||||||||||||||||||||||||||||||||||||||||||
Assessment of Risk of Bleeding
The risk factors of bleeding with anticoagulation therapy are:[2]
- Age > 75 years
- Alcohol abuse
- Anemia
- Antiplatelet therapy
- Cancer
- Comorbidity and reduced functional capacity
- Diabetes
- Frequent falls
- Liver failure
- Metastatic cancer
- Poor anticoagulant control
- Previous bleeding
- Prior stroke
- Recent surgery
- Renal failure
- Thrombocytopenia
Shown below is a table summarizing the risk of bleed based on the number of risk factors. Note that, although the presence of one risk factor signify moderate risk of bleeding, if the single risk factor is severe (such as severe thrombocytopenia or recent major surgery) then the patient is at high risk of bleeding despite the presence of a single risk factor.
| Risk of bleeding | Number of risk factors[2] |
| Low Risk | 0 |
| Moderate Risk | 1 |
| High Risk | ≥2 |
Do's
Don'ts
References
- ↑ Guyatt GH, Akl EA, Crowther M, Gutterman DD, Schuünemann HJ, American College of Chest Physicians Antithrombotic Therapy and Prevention of Thrombosis Panel (2012). "Executive summary: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines". Chest. 141 (2 Suppl): 7S–47S. doi:10.1378/chest.1412S3. PMC 3278060. PMID 22315257.
- ↑ 2.0 2.1 Kearon C, Akl EA, Comerota AJ, Prandoni P, Bounameaux H, Goldhaber SZ; et al. (2012). "Antithrombotic therapy for VTE disease: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines". Chest. 141 (2 Suppl): e419S–94S. doi:10.1378/chest.11-2301. PMC 3278049. PMID 22315268.