Venous thromboembolism
Venous thromboembolism Microchapters |
Editors-in-Chief: C. Michael Gibson, M.S., M.D. Associate Editor-In-Chief: Ujjwal Rastogi, MBBS [1]
Synonyms and keywords: VTE
Overview
Pathophysiology
Classification Scheme
Epidemiology
Risk Factors
Differential Diagnosis
Complication
Diagnosis
Physical examination
Lab Tests
- Arterial blood gas
- Plasma D-dimer
- Plasma D-dimer>500 ng/ml, PE present (Found to be 97% sensitive and 45% specific)
- Plasma D-dimer<500 excludes PE (Have a high negative predictive value)
- Workup for hypercoagulation: which include
- Activated protein C resistance
- factor V Leiden mutation
- Protein C
- protein S, free and total.
- Antithrombin
- Lupus anticoagulant
- Anticardiolipin antibodies
- Plasma homocysteine values
Electrocardiogram
ECG is important as it helps in ruling out myocardial infarction which also present with chest pain.
Chest x ray
It is more helpful in making an alternative diagnoses (Eg. pneumonia which can present with dyspnea and chest pain), than for diagnosing VTE. Xray findings are most often normal in patients with PE, It may reveal:
- Enlarged right descending pulmonary artery
- Decreased pulmonary vascularity (Westermark sign)
- Elevation of the hemidiaphragm (Hampton hump)
In case of an infarction:
- A wedge-shaped infiltrate or
- Pleural effusion might be present.
Ultrasonography
- A Doppler USG detects thrombus within a vein.
- Normal vein:free of internal echoes, compresseble.
- Acute DVT:internal echoes are present, non compressible vein.
With the color flow Doppler, motion and the direction of flow are assessed in a far better way.
CT
It involves the pulmonary vessels imaging by use of intravenous contrast material and is diagnosed by filling defects, which are either central or adherent to the wall.
- Advantages
- Minimally invasive
- Allows concurrent visualization of the parenchyma, pleura, and mediastinum.
- Limitations
- Need for contrast
- Dose of radiation is comparatively higher than that of other diagnostic procedures
Prophylaxis
A study involving data from 16 acute care hospitals confirmed the occurrence of VTE in patient who did not received thrombo-prophylaxis in-spite of being at risk and having no contraindication for thromboprophylaxis [1].
VTE occurs in approximately 50% patients undergoing major orthopedic surgery who do not receive appropriate thromboprophylaxis [2].
In post-surgical patients, following strategies have been helpful in reducing the risk of VTE[2]:
- Change in life style.
- Healthy diet[3].
- Exercise.
- Decreasing body weight.
- Avoiding smoking.
- Prevention of dehydration.
- Maintaining normal blood pressure.
Following recommendations are made for patients falling into other categories[2] :
- Patients at low risk for DVT:
- Graduated elastic compressions.
- Bedridden patients:
- Pneumatic compression.
- Patients in Critical Care Unit:
- Heparins (Heparin, lmwh, unfractionated heparin)
- Warfarin.
- Direct thrombin inhibitor.
Treatment
See also
- Venous thromboembolism: Under-recognized and under-treated
- Deep vein thrombosis
- Pulmonary embolism
- Thrombosis
- Nephrotic syndrome and risk of venous and arterial thromboembolism
References
- ↑ Amin A, Spyropoulos AC, Dobesh P, Shorr A, Hussein M, Mozaffari E, Benner JS (2010). "Are hospitals delivering appropriate VTE prevention? The venous thromboembolism study to assess the rate of thromboprophylaxis (VTE start)". J. Thromb. Thrombolysis. 29 (3): 326–39. doi:10.1007/s11239-009-0361-z. PMC 2837191. PMID 19548071. Retrieved 2011-12-10. Unknown parameter
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ignored (help) - ↑ 2.0 2.1 Goldhaber SZ (2004). "Prevention of recurrent idiopathic venous thromboembolism". Circulation. 110 (24 Suppl 1): IV20–4. doi:10.1161/01.CIR.0000150641.65000.f2. PMID 15598644. Retrieved 2011-12-10. Unknown parameter
|month=
ignored (help) - ↑ Galson SK (2009). "Prevent deep vein thrombosis and pulmonary embolism with a healthful diet". J Am Diet Assoc. 109 (4): 592. doi:10.1016/j.jada.2009.02.020. PMID 19328250. Retrieved 2011-12-10. Unknown parameter
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ignored (help)