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Three Part Question

In [patients with a DVT presentation in the Emergency Department] can [the ultrasound transducer compression test] [precipitate a thromboembolic event?]

Clinical Scenario

A 47-year-old woman presents to the emergency department with left calf pain which came on suddenly, making walking difficult. Typical DVT risk factors are present and the examination is consistent with this. Being proficient with the portable ultrasound unit you decide to perform a "rule-in" compression test of the vasculature in the left leg. However, a colleague challenges this decision, questioning whether the test itself could cause an embolus when compressing the thrombus. You therefore wonder if there is any evidence for this adverse effect, in which case you would prefer to start anticoagulation without this information and defend your diagnosis on clinical grounds.

Search Strategy

Medline In-process & other non-indexed citations and Ovid Medline 1950 – May Week 1 2007 using the Ovid interface, and EBM Reviews - Cochrane Central Register of Controlled Trials 2nd Quarter 2007, and EBM Reviews - Cochrane Database of Systematic Reviews 1st Quarter 2007 using the Ovid interface.
[(deep vein thrombosis.mp.) OR (DVT.mp.) OR (thromboembolism.mp.) OR (thrombo-embolism.mp.)] AND [(compression tes$.mp.)] AND [(contraindica$.mp.) OR (detrimen$.mp.) OR (deleterious.mp.) OR (precipitate) OR (thromboembolism.mp.) OR (thrombo-embolism.mp.)].

Search Outcome

Altogether 0 papers were found in Medline, 0 papers were found in the Cochrane Central Register of Controlled Trials 2nd Quarter 2007 and 0 papers were found in the Cochrane Database of Systematic Reviews 1st Quarter 2007. Additionally a PubMed search [compression test, DVT, embolism, risk] yielded 0 relevant papers.

Comment(s)

The lack of evidence in this area is not surprising as a controlled clinical trial would be unlikely to gain ethical approval. However this presents the clinician with the all-too-familiar situation of wondering whether or not they should use this particular investigation. Published work advocates a focussed ultrasound technique as the 'Gold Standard' in identifying DVT. It is becoming an increasingly popular technique in the Emergency and Acute Medical Departments. However, clinicians should give due consideration to the fact that compression sonography for possible DVT has not been evaluated against any risk of causing clinically significant emboli. This information is desirable for accepted good clinical practice.

Clinical Bottom Line

Currently there is no evidence to suggest that compressing vessels in order to identify a DVT could cause an embolic event. Therefore we can consider ultrasound assessment a safe reliable investigation for the diagnosis of DVT with no evidence of causing harm.