Journal Jam 1: Age Adjusted D-dimer with Jeff Kline and Jonathan Kirschner

The problem until now has been that the older the patient, the more likely the D-dimer is to be positive whether they have a PE or not, so many of us have thrown the D-dimer out the window in older patients and go straight to CTPA, even in low risk patients.  If you are a risk averse doc, this strategy will lead to over-utilization of resources, huge costs, length of stay, radiation effects etc; and if you’re not so risk averse, then you might decide not to work up the low risk older patient at all and miss clinically important PEs.

For all the questions discussed on this podcast, the original Google Hangout interview from which this podcast was based, and the crowd sourced opinions from around world, visit the ALiEM website. Many thanks to all the talented people who made this podcast possible. Together, we're smarter!



Published by Anton Helman Sept 2014

Cite this podcast as: DeWit, K, Kline, J. Age Adjusted D-dimer with Jeff Kline and Jonathan Kirschner. Emergency Medicine Cases. September, 2014. https://emergencymedicinecases.com/journal-jam-1-age-adjusted-d-dimer-jeff-kline-jonathan-kirschner/. Accessed [date].

Update 2015: Global Emergency Medicine Journal Club: A Social Media Discussion About the Age-Adjusted D-Dimer Cutoff Levels to Rule Out Pulmonary Embolism Trial. Annals of EM, published online March 31st, 2015 Full PDF



Expert Peer Review of this Journal Jam podcast

Dr. Kerstin De Wit (née Hogg), MBChB, MD, MRCP, FCEM, FRCPC. Divisions of Thrombosis & Emergency Medicine, Department of Medicine, McMaster University, Canada. Prepared in September, 2014.

Low Risk Patients…

I agree that cancer and recent hospitalization are risk factors for pulmonary embolism (PE). The Wells score helps to define the low risk population, and includes the clinical gestalt question 'is PE the most likely diagnosis?' D-dimer should not be used to rule out PE in the intermediate or high risk patients (or according to the modified Wells PE score – the PE likely group [e.g. score > 4.0]). In the conclusion you state if your clinical gestalt is high, don't use age adjusted D-dimer, but actually I would extend that statement to say you shouldn't use D-dimer at all if you have a compelling suspicion.

What about the VQ scan?

A lot of the discussion focuses on CT Pulmonary Angiogram (CTPA). It seems to me that this is a great time to remind emergency physicians that we can also order VQ scans. We should consider VQ as first line-imaging for young patients (decreasing the risk of lung and breast cancer in later life). In other words, if you are a 'risk averse' clinician, you should utilize VQ. The path of most harm will include ordering CT scans on lots of young people with positive D-dimers. Many community hospitals have access to a regional Thrombosis unit where the VQ scan can be performed the next day.

The second issue with CT is the 'over diagnosis' of PE (or the false positive rate). Many patients are being diagnosed with single subsegmental PE on CT. CT does not visualize a clot, instead it demonstrates a filling defect (causes of which could be many). Emerging evidence is compelling that these are false positive scans. VQ avoids this issue.

Prevalence & your patient population

As a Thrombosis and Emergency clinician, who has worked in both the UK and Canada, I am in a prime position to reflect more on the differences in various countries. The prevalence of PE amongst all patients investigated for PE (starting with D-dimer and clinical ...