Posts Tagged dvt

Fear and Loathing in D-Dimer

Am I the only one who hates the d-dimer for pulmonary embolism? I can’t imagine that I am. It was supposed to reduce our number of CTs, but the data suggests that it has instead increased them. (Full disclaimer, I never practiced in the days of V/Q scans or the days without d-dimer, but this is what I’m told.)

I find my practice pattern typically using the PERC Rule and/or Well’s Criteria for PE to identify well-appearing people who are “very low risk,” who would likely be harmed more than benefitted by a d-dimer test. And then for low-risk, I’ll end up using a d-dimer.

But when the computer screen blips that the result is back, I get a similar little blip in my chest, hoping it’s going to be negative. Interesting that I feel this way, given that I have no other reaction like this, except occasionally while waiting for the altered patient’s rectal temperature.

On one hand, I wonder, if this is the reaction I’m feeling, hoping and trying to mentally will the number to be negative when I click the “View Results” button, should I have even ordered the test to begin with? And on the other is how atypical, nefarious, and sometimes-weird presentations of pulmonary embolism can be. And then on the third hand: is the pulmonary embolism in the otherwise healthy, young, well-appearing person actually cause for alarm? (Some experts would suggest that our bodies are in a constant state of coagulation/anticoagulation, and that we’re all walking around with occasional, small PEs that our lungs dissolve or filter.) Maybe this is different (“benign PE”) from the PE in the cancer patient, or the hypotensive patient, or the one with the saddle thrombus. And on the fourth hand: there’s not even any good data that anticoagulation is of any benefit in pulmonary embolism (even though it’s the standard of care, and we all still give it).

Maybe I just hate PEs, or ruling them out in seemingly low-risk patients: the time, the money, and most of all, the contrast load and radiation exposure. But for now, I guess we’re stuck with our imperfect tests, clinical gestalt, and bedside evaluations of risk and benefit.

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