Deep vein thrombosis diagnostic approach: Difference between revisions
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A number of invasive (venography) and non-invasive tests (impedance plethysmography, compression ultrasonography, D-dimer testing) are available for diagnosis. Compression ultrasonography is the noninvasive diagnosis of choice for patients with a first episode of suspected DVT. | A number of invasive (venography) and non-invasive tests (impedance plethysmography, compression ultrasonography, D-dimer testing) are available for diagnosis. Compression ultrasonography is the noninvasive diagnosis of choice for patients with a first episode of suspected DVT. | ||
In a patient population with high prevalence of [[VTE]], a negative [[D-dimer]] assay may be insufficient to rule out DVT as a single test, and moreover not all D-dimer assays are validated for this. However, a D-dimer level <500 ng/mL by ELISA along with a low clinical probability ([[Wells score calculator for DVT|Wells score]]) or other negative non-invasive tests may be useful in excluding DVT, without doing ultrasound. | In a patient population with high prevalence of [[VTE]], a negative [[D-dimer]] assay may be insufficient to rule out DVT as a single test, and moreover not all D-dimer assays are validated for this. However, a D-dimer level <500 ng/mL by ELISA along with a low clinical probability ([[Wells score calculator for DVT|Wells score]])<ref name="pmid10744147">{{cite journal |author=Wells PS, Anderson DR, Rodger M, Ginsberg JS, Kearon C, Gent M, Turpie AG, Bormanis J, Weitz J, Chamberlain M, Bowie D, Barnes D, Hirsh J |title=Derivation of a simple clinical model to categorize patients probability of pulmonary embolism: increasing the models utility with the SimpliRED D-dimer |journal=Thromb. Haemost. |volume=83 |issue=3 |pages=416–20 |year=2000 |month=March |pmid=10744147 |doi=|url=http://www.schattauer.de/index.php?id=1268&L=1&pii=th00030416&no_cache=1 |accessdate=2012-05-01}}</ref> or other negative non-invasive tests may be useful in excluding DVT, without doing ultrasound. | ||
Compression ultrasonography has a positive predictive value of 94 percent (95% CI: 87-98 percent). If the clinical suspicion of DVT is high even after a negative CUS, a repeat study should be done within a week. Complete lower extremity ultrasonography may eliminate the need for repeat testing, but a positive CUS demands user expertise, and requires specialized instrumentation. The algorithm below presents a possible diagnostic approach. | Compression ultrasonography has a positive predictive value of 94 percent (95% CI: 87-98 percent). If the clinical suspicion of DVT is high even after a negative CUS, a repeat study should be done within a week. Complete lower extremity ultrasonography may eliminate the need for repeat testing, but a positive CUS demands user expertise, and requires specialized instrumentation. The algorithm below presents a possible diagnostic approach. | ||
Revision as of 17:39, 15 May 2012
Editors-in-Chief: C. Michael Gibson, M.S., M.D. Associate Editor-In-Chief: Ujjwal Rastogi, MBBS [1]; Kashish Goel, M.D.
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Overview
A number of invasive (venography) and non-invasive tests (impedance plethysmography, compression ultrasonography, D-dimer testing) are available for diagnosis. Compression ultrasonography is the noninvasive diagnosis of choice for patients with a first episode of suspected DVT.
In a patient population with high prevalence of VTE, a negative D-dimer assay may be insufficient to rule out DVT as a single test, and moreover not all D-dimer assays are validated for this. However, a D-dimer level <500 ng/mL by ELISA along with a low clinical probability (Wells score)[1] or other negative non-invasive tests may be useful in excluding DVT, without doing ultrasound.
Compression ultrasonography has a positive predictive value of 94 percent (95% CI: 87-98 percent). If the clinical suspicion of DVT is high even after a negative CUS, a repeat study should be done within a week. Complete lower extremity ultrasonography may eliminate the need for repeat testing, but a positive CUS demands user expertise, and requires specialized instrumentation. The algorithm below presents a possible diagnostic approach.
CUS stands for Compression Ultrasonography; D-dimer is the highly sensitive assay.
Clinical judgement and local availability should be considered in patients with moderate probability of DVT. CUS may be preferred in patients with comorbid conditions associated with elevated D-dimer levels.
Adapted from ACCP guidelines[2].
Considerations
- Whole-leg ultrasound may be preferred in those who have severe symptoms of calf DVT or are unable to come for serial testing.
- CT scan venography, MR venography, or MR direct thrombus imaging may be used in those patients in whom ultrasound is not practical (leg cast, excessive edema) or non-diagnostic.
References
- ↑ Wells PS, Anderson DR, Rodger M, Ginsberg JS, Kearon C, Gent M, Turpie AG, Bormanis J, Weitz J, Chamberlain M, Bowie D, Barnes D, Hirsh J (2000). "Derivation of a simple clinical model to categorize patients probability of pulmonary embolism: increasing the models utility with the SimpliRED D-dimer". Thromb. Haemost. 83 (3): 416–20. PMID 10744147. Retrieved 2012-05-01. Unknown parameter
|month=ignored (help) - ↑ Bates SM, Jaeschke R, Stevens SM; 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. PMID 22315267. Unknown parameter
|month=ignored (help)