Deep Vein Thrombosis - Wikipedia, The Free Encyclopedia

8/6/2019 Deep Vein Thrombosis - Wikipedia, The Free Encyclopedia

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(http://www.diseasesdatabase.com

/ddb3498.htm)

MedlinePlus 000156 (http://www.nlm.nih.gov

/medlineplus/ency/article

/000156.htm)

eMedicine med/2785

(http://www.emedicine.com

/med/topic2785.htm)

MeSH D020246 (http://www.nlm.nih.gov

/cgi/mesh/2011/MB_cgi?field=uid&term=D020246)

1 Signs and symptoms2 Cause3 Diagnosis

3.1 Physical examination3.2 Probability scoring3.3 Blood tests3.4 Imaging

4 Prevention

4.1 General medical inpatients4.2 Surgery patients4.3 Pregnancy4.4 Travellers

5 Management5.1 Anticoagulation5.2 Thrombolysis

5.3 Thrombectomy5.4 Compression stockings5.5 Inferior vena cava filter5.6 Hospitalization

6 Prognosis7 Epidemiology8 See also

9 References10 External links

There may be no symptoms referable to the location of the DVT, but the classical symptoms of DVT include pain, swelling and redness of the leg and

dilation of the surface veins. In up to 25% of all hospitalized patients, there may be some form of DVT, which often remains clinically inapparent(unless pulmonary embolism develops).

eep vein thrombosis - Wikipedia, the free encyclopedia http://en.wikipedia.org/wiki/Deep_vein_thrombosis

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Abdominal computed tomographic

scan showing a common iliac vein

thrombosis. The arrow indicates the

filling defect in the vein visualised

using radiocontrast.

The gold standard is intravenous venography, which involves injecting a peripheral vein of the affected limb

with a contrast agent and taking X-rays, to reveal whether the venous supply has been obstructed. Because of

its invasiveness, this test is rarely performed.

Physical examination

Homans sign: Dorsiflexion of foot elicits pain in posterior calf. Pratt's sign: Squeezing of posterior calf elicits

pain. However, these medical signs do not perform well and are not included in clinical prediction rules that

combine best findings in order to diagnose DVT.[8]

Probability scoring

In 2006, Scarvelis and Wells overviewed a set of clinical prediction rules for DVT,[9] on the heels of a widely

adopted set of clinical criteria for pulmonary embolism.[10][11]

Wells score or criteria: (Possible score -2 to 9)

Active cancer (treatment within last 6 months or palliative) +1 point1.Calf swelling >3 cm compared to other calf (measured 10 cm below tibial tuberosity) +1 point2.Collateral superficial veins (non-varicose) +1 point3.Pitting edema (confined to symptomatic leg) +1 point4.Previous documented DVT +1 point.5.Swelling of entire leg +1 point6.Localized pain along distribution of deep venous system +1 point7.

Paralysis, paresis, or recent cast immobilization of lower extremities +1 point8.Recently bedridden > 3 days, or major surgery requiring regional or general anesthetic in past 4 weeks +1 point9.Alternative diagnosis at least as likely -2 points10.

Interpretation:

Score of 2 or higher - deep vein thrombosis is likely. Consider imaging the leg veins.Score of less than 2 - deep vein thrombosis is unlikely. Consider blood test such as d-dimer test to further rule out deep vein thrombosis.

Blood tests


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An ultrasound image demonstrating a

blood clot in the left common femoral

vein.

D-dimer

Main article: d-dimer

In a low-probability situation, current practice is to commence investigations by testing for D-dimer levels. This cross-linked fibrin degradation

product is an indication that thrombosis is occurring, and that the blood clot is being dissolved by plasmin. A low D-dimer level should prompt other

possible diagnoses (such as a ruptured Baker's cyst, if the patient is at sufficiently low clinical probability of DVT).[12][13]

Other blood tests

Other blood tests usually performed at this point are[citation needed]:

complete blood countPrimary coagulation studies: PT, APTT, Fibrinogenliver enzymesrenal function and electrolytes

Imaging

Impedance plethysmography, Doppler ultrasonography, compression ultrasound scanning of the leg veins,combined with duplex measurements (to determine blood flow), can reveal a blood clot and its extent (i.e.

whether it is below or above the knee). Duplex Ultrasonography, due to its high sensitivity, specificity and

reproducibility, has replaced venography as the most widely used test in the evaluation of the disease. This test

involves both a B mode image and Doppler flow analysis. It is most sensitive and specific for detecting

proximal thrombi (in the popliteal and femoral veins), but substantially less so for distal thrombi (in the calf

veins).[14]

Clinical practice guidelines by the American College of Chest Physicians (ACCP) provide recommendations

on DVT prophylaxis in hospitalized patients.[15]

General medical inpatients

Regarding general medical inpatients the guidelines state, "In acutely ill medical patients who have been

admitted to the hospital with congestive heart failure or severe respiratory disease, or who are confined to bed


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syndrome.[39]

Inferior vena cava filter

Main article: Inferior vena cava filter

Inferior vena cava filter reduces pulmonary embolism[40] and is an option for patients with an absolute contraindiciation to anticoagulant treatment

(e.g., cerebral hemorrhage) or those rare patients who have objectively documented recurrent PEs while on anticoagulation, an inferior vena cava

filter (also referred to as a Greenfield filter) may prevent pulmonary embolisation of the leg clot. However these filters are themselves potential of

thrombosis,[41] IVC filters are viewed as a temporizing measure for preventing life-threatening pulmonary embolism.[42]

Hospitalization

Treatment at home is an option according to a meta-analysis by the Cochrane Collaboration.[43] Hospitalization should be considered in patients with

more than two of the following risk factors as these patients may have more risk of complications during treatment [44]:

bilateral DVTrenal insufficiencylow body weight (


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Deep Vein Thrombosis - Wikipedia, The Free Encyclopedia

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