A patient presents with an asymmetric leg with trace pitting edema in the affected leg. What is your diagnostic approach to such a patient? What is the role of D-dimer and ultrasound (U/S)? Does this match the 2012 American College of Chest Physicians (ACCP) guidelines?

The first step is to determine your patient’s pretest probability because the recommendations vary based on risk. I can tell you that many ED patients come in with a Wells score of 1-2, which places them in the “moderate pretest probability” category. There are 2 approaches you can take based on the availability of resources at your site (high-sensitivity D-dimer or U/S) and the patient’s comorbidities. Are you referring your patient for a repeat outpatient ultrasound, if warranted?Walk through various patient scenarios to see how the D-Dimer and U/S come into play.

PV Card: Diagnosting DVT – ACCP Evidence Based Guidelines

Adapted from [1] Go to ALiEM (PV) Cards for more resources.

Thanks to Dr. Jason West (EM resident at Jacobi/Montefiore) for this card idea and deciphering the complex recommendations from the publication.


  1. Bates S, Jaeschke R, Stevens S, et al. Diagnosis of DVT: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest. 2012;141(2 Suppl):e351S-418S. [PubMed]
Michelle Lin, MD
ALiEM Founder and CEO
Professor and Digital Innovation Lab Director
Department of Emergency Medicine
University of California, San Francisco
Michelle Lin, MD


Professor of Emerg Med at UCSF-Zuckerberg SF General. ALiEM Founder @aliemteam #PostitPearls at https://t.co/50EapJORCa Bio: https://t.co/7v7cgJqNEn
Michelle Lin, MD