sinaiem.org

Please join us for Emergency Medicine Department Conference on Wednesday, August 13th at 9AM in Mount Sinai’s Hatch Auditorium.

Our featured speaker is Dr. Eric Legome, Chair of St. Vincent’s Emergency Department. We will also be featuring innovative lectures from Drs. Wolfram Chynoll and Deborah Marin.

9am    Grand Rounds — Dr. Eric Legome
10am    Administrative Lecture Series — Drs. Wolfram Schynoll & Deborah Marin
12pm    Pedatric Core Lecture: Rashes — Dr. Sylvia Garcia
1pm    Pediatric M&M — Dr. Kumar

Lunch will be served and some breakfast amenities will be provided. Additionally, there will be a resident feedback session immediately following conference. Finally, more photos of our residents will be taken — so if you haven’t had your closeup yet, please dress appropriately.

There’s a certain symmetry to starting the first journal club of the year studying d-dimer for dissection (last time around, we looked at the PERC rule and d-dimer for PE). This month, Bing examined a paper by Ohlmann and others, called “Diagnostic and prognostic value of circulating D-Dimers in patients with acute aortic dissection” (Crit Care Med. 2006 May;34(5):1358-64. PMID: 16557157). For background, we also read “D-dimer in ruling out acute aortic dissection: a systematic review and prospective cohort study” (Eur Heart J. 2007 Dec;28(24):3067-75. PMID: 17986466) and got some perspective on D-dimer the with Klompas addition to the JAMA rational clinical exam series: “Does This Patient Have an Acute Thoracic Aortic Dissection?” (JAMA 2002;287(17):2262-2272. PMID: 11980527).

The clinical background was useful in delineating the scope of the problem: acute aortic dissection (AAD) is rare — in some rigorous European surveys, incidence is 3-4 / 100,000 and in EDs, 2-3 of 1000 chest pain patients have AAD (so if you see about 1000 chest pain patients in the course of your residency…). We miss it a lot — Klompas said 39% of patients have a delay in diagnosis of more than 24 hours, 10% of autopsies for show missed dissections, and we only suspect AAD properly less than half the time (as low as 15% of the time).

There are a few key features of dissection that should set off alarm bells for AAD — pulse deficits and blood pressure cuff differences > 20 mmHg (positive likelihood ratio 5.7), focal neuro deficits (LR+ 6-33), and a description of “tearing pain” (LR+ 10.8). But many other signs are sensitive but not that specific, or not even that sensitive (and ‘tearing pain’ is only reported 39% of the time, with focal neuro deficits found just 17% of the time). Chest Xrays have a LR+ of around 2, and are only 60-80% sensitive (though a completely normal CXR — normal width mediastinum and normal aortic knob, have a LR- 0f 0.3).

What’s really needed to diagnose AAD is not-so-standard imaging, like CT, TEE, or MRI (all 98% sensitive or greater, with specificies in the high 90’s as well). So there’s an opportunity for a lab test to step in and help us guide decisionmaking. And d-dimer, a substance released by fibrinolytic activity unleashed when the extrinsic pathway is activated in dissection, in theory could work well as a marker.

Read More »