Date: November 13th, 2019

Reference: van der Pol et al. Pregnancy-Adapted YEARS Algorithm forDiagnosis of Suspected Pulmonary Embolism. NEJM 2019

Guest Skeptic: Dr. Theresa Robertson-Chenier is currently an Emergency Physician practicing at the Peterborough Regional Health Centre. She is also an adjunct faculty member with Queen’s University, Department of Family Medicine.

Case: A 32-year-old female, G1P0, who is 22 weeks pregnant, presents to your local emergency department with the chief complaint of shortness of breath. She states that for the last one week she has had progressive shortness of breath on exertion. She denies any chest pain, fever, cough or leg swelling. She has no history of venous thromboembolic (VTE) disease like deep vein thrombosis (DVT) or pulmonary embolism (PE). But recently she drove seven hours from London, Ontario to Montreal, Quebec. She is worried about the possibility of a PE. She is otherwise healthy, takes only prenatal vitamins and has no allergies. She is terrified about any radiation exposure in pregnancy and has read on google that there is a blood test you can order to rule out PE.

Background: We have covered VTE a number of times on the SGEM. This has even included a few of episodes with the PE guru and PERC rule creator Dr. Jeff Kline. However, we have never looked at the YEARS criteria study published by Van der Hulle T et al (The Lancet 2017).

* SGEM#51: Home (Discharging Patients with Acute Pulmonary Emboli Home from the Emergency Department)

* SGEM#126: Take me to the Rivaroxaban – Outpatient treatment of VTE

* SGEM#163: Shuffle off to Buffalo to Talk Thrombolysis for Acute Pulmonary Embolism

* SGEM#219:Shout, Shout, PERC Rule Them Out

The YEARS algorithm starts with the clinician suspecting an acute PE. Then they order a D-dimer and apply the YEARS clinical decision instrument. It has three items with each getting one point:

* Clinical signs of DVT

* Hemoptysis

* PE most likely diagnosis

If there are zero YEARS items and the d-dimer is <1,000ng/ml then a PE is excluded. If there are zero YEARS items but the d-dimer is equal to or greater than 1,000ng/ml then a CT pulmonary angiography (CTPA) scan is needed to rule out a PE.

If there are one or more YEARS items and the d-dimer is <500ng/ml then a PE is excluded. If there are one or more YEARS items but the d-dimer is equal to or greater than 500ng/ml then a CTPA scan is needed to rule out a PE.

While this publication was interesting, it was a prospective observational study from the Netherlands. There was a study by Kabrhel et al (AEM 2018) that was done in 17 hospitals in the USA. They compared usual care for possible PE vs. YEARS criteria. They enrolled 1,789 patients and 84 (4%) had a PE. Using standard d-dimer criteria, 53% would not have been imaged (2 misses). YEARS avoided imaging in 67%, but had 6 misses. Standard care had a sensitivity 97.6% vs, 92.9% for YEARS. It would be better if there was a randomized control trial comparing usual care to YEARS. In addition, the case you presented was of a pregnant woman. In the original YEARS study from 2017 it said pregnancy was an exclusion.

Clinically, it can be difficult to diagnosis PE in pregnancy because of the over...