Deep vein thrombosis resident survival guide: Difference between revisions
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Deep vein thrombosis (DVT) is the formation of a blood clot ("thrombus") in a deep vein. | Deep vein thrombosis (DVT) is the formation of a blood clot ("thrombus") in a deep vein. | ||
Wells | Wells scoring system is used for predicting probability of DVT: | ||
It is calculated based on following scoring criteria | It is calculated based on following scoring criteria | ||
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* Alternative diagnosis more likely than DVT (Baker's cyst, cellulitis, muscle damage, superficial venous thrombosis, post phlebitic syndrome, inguinal lymphadenopathy, external venous compression) (-2 points) | * Alternative diagnosis more likely than DVT (Baker's cyst, cellulitis, muscle damage, superficial venous thrombosis, post phlebitic syndrome, inguinal lymphadenopathy, external venous compression) (-2 points) | ||
The results are interpreted as follows: | The results are interpreted as follows: <br> | ||
3-8 Points: High probability of DVT | 3-8 Points: High probability of DVT <br> | ||
1-2 Points: Moderate probability | 1-2 Points: Moderate probability <br> | ||
-2-0 Points: Low Probability | -2-0 Points: Low Probability | ||
Revision as of 19:11, 24 February 2014
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1];Associate Editor(s)-in-Chief: Abdurahman Khalil, M.D. [2]
Definition
Deep vein thrombosis (DVT) is the formation of a blood clot ("thrombus") in a deep vein.
Wells scoring system is used for predicting probability of DVT:
It is calculated based on following scoring criteria
- Paralysis, paresis or recent orthopedic casting of lower extremity (1 point)
- Recently bedridden (more than 3 days) or major surgery within past 4 weeks (1 point)
- Localized tenderness in deep vein system (1 point)
- Swelling of entire leg (1 point)
- Calf swelling 3 cm greater than other leg (measured 10 cm below the tibial tuberosity) (1 point)
- Pitting edema greater in the symptomatic leg (1 point)
- Collateral non varicose superficial veins (1 point)
- Active cancer or cancer treated within 6 months (1 point)
- Alternative diagnosis more likely than DVT (Baker's cyst, cellulitis, muscle damage, superficial venous thrombosis, post phlebitic syndrome, inguinal lymphadenopathy, external venous compression) (-2 points)
The results are interpreted as follows:
3-8 Points: High probability of DVT
1-2 Points: Moderate probability
-2-0 Points: Low Probability
Causes
Life Threatening Causes
Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated. Although, deep vein thrombosis is by itself not life threatening, if not treated it may progress to a condition called as pulmonary embolism. Pulmonary embolism is severely life threatening and often a fatal condition.
Common Causes
Congenital:
- Enzyme deficiency (protein S deficiency, protein C deficiency, antithrombin deficiency)
- Mutations (factor V leiden, prothrombin gene)
- Anatomic (May-Thurner syndrome, Cockett syndrome)
Acquired:
- Medications (oral contraceptives, hormone replacement therapy, tamoxifen)
- Illness (cancer, acute myocardial infarction, congestive heart failure, sepsis, burns)
- Prolonged immobilization (transcontinental flights, operation under general anesthesia, pelvic/hip surgery, stroke/paraplegia)
Diagnostic approach
Pain Swelling Erythema Venous dilation | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pretest Probability of DVT Major points 1-Active cancer 2-Paralysis,paresis or plastic immobilization of leg or foot 3-Recent bed rest >3 days or major surgery in the last 4 weeks or both 4-Calf or thigh swelling 5->3 cm calf swelling below the tibial tuberosity 5-Strong F/H of DVT Minor points 1-H/O recent trauma to the suspected leg 2-Pitting edema in the suspected leg 3-Dilated superficial veins in the suspected leg 4-Hospitalization in the last 6 months 5-Erythema | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Low probability* | Moderate probability* | High probability* | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
D-Dimer | D-Dimer | U/S | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Negative | Positive | Negative | Positive | Negative | Positive | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
No DVT | U/S | No DVT | U/S | Repeat in 7 days | D-Dimer | Treat | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Negative | Positive | Negative | Positive | Negative | Positive | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
No DVT | Treat | Repeat in 7 days | Treat | No DVT | Repeat in 7 days | U/S[1] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
- High probability:
>3 major points+ no alternative diagnosis
or 2 major points + 2 minor points + no alternative diagnosis. - Low probability:
1 major point +≥2 minor + alternative diagnosis
or 1 major + ≥1 minor + no alternative diagnosis
or no major points+ irrespective of minor points +irrespective of diagnosis. - Moderate probability:
neither high or low probability.[2]
According to Institute for Clinical Systems Improvement (ICSI), U/S should be used as initial test for moderate probability rather than high sensitivity D-dimer.[3]
Management
DVT confirmed | |||||||||||||||||||||||||||||||
Hemodynamically unstable(massive PE) SBP<90 mm Hg or 40 mm Hg drop Syncope Severe hypoxemia or respiratory distress | Hemodynamically stable | Contraindication for Anticoagulation therapy Absolute Active severe hemorrhage Intracranial hemorrhage Relative Recent surgery, trauma, anemia,GI bleeding, PUD | |||||||||||||||||||||||||||||
Thrombolytic therapy | LMWH or UFH(target INR:2.5, monitor Plt count)+ Warfarin or Fondaparinux | IVC filter | |||||||||||||||||||||||||||||
Do's
- For moderate to high probability suspicion start initial therapy while waiting for diagnostic test results. When there is a low probability, the decision of treatment will depend on the diagnostic test results.
- Start vitamin K antagonist(Warfarin) no more than 1 or days after start UFH or LMWH.The initial dose for the first 2 days should be 10 mg daily then in accordance to the required INR measurements.
- INR therapeutic ranges are 2.0-3.0 and Target INR is 2.5 and that is applied for patients with hypercoagulable state (antiphospholipid syndrome).
- For IV UFH administration use weight adjusted dose for the initial bolus(80 unit/kg) and the following continuous infusion(18 unit/kg/hr), and for subcutaneous UFH (first dose 333 units/kg, then 250 units/kg).
- For patients with CKD/ESRD reduce LMWH than standered dose.
- Fondaparinux administered subcutaneously in fixed doses 7.5 mg and if the patient weight>100 kg the dose will be 10 mg.[4]
Don'ts
Avoid with VKA therapy all of the following:
- NSAIDs including cox-2 inhibitors.
- Antiplatelet unless benefit outweighs harm (ACS, mechanical valves, coronary stents or bypass surgery).
- Vitamin K supplement(not recommended).
References
- ↑ Bates SM, Jaeschke R, Stevens SM, Goodacre S, Wells PS, Stevenson MD; et al. (2012). "Diagnosis of DVT: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines". Chest. 141 (2 Suppl): e351S–418S. doi:10.1378/chest.11-2299. PMC 3278048. PMID 22315267.
- ↑ Wells PS, Anderson DR, Bormanis J, Guy F, Mitchell M, Gray L; et al. (1997). "Value of assessment of pretest probability of deep-vein thrombosis in clinical management". Lancet. 350 (9094): 1795–8. doi:10.1016/S0140-6736(97)08140-3. PMID 9428249.
- ↑ Skeik N, Dupras D (2013 Jan). "Venous Thromboembolism Diagnosis and Treatment". Institute for Clinical Systems Improvement (ICSI). Check date values in:
|date=
(help) - ↑ Holbrook A, Schulman S, Witt DM, Vandvik PO, Fish J, Kovacs MJ; et al. (2012). "Evidence-based management of anticoagulant therapy: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines". Chest. 141 (2 Suppl): e152S–84S. doi:10.1378/chest.11-2295. PMC 3278055. PMID 22315259.