Hot off the presses: #POCUS for Aortic Dissection
For the last few years, while doing bedside teaching at EDE 2 or EDE 3, or in my own ED, I have been occasionally sharing useful tidbits regarding the utility of POCUS for aortic dissection. I have been mentioning that a PCE, an aortic flap (at any level of the aorta), and a dilated aortic root on PSL (I have been using the textbook cutoff of 4 cm) are clues to the possible presence of a dissection. No doubt that many others have picked up on this as well. But I have been always cautious in stating that POCUS can help pick up a significant minority of dissections. Boy, was I wrong about the minority part!
Dr Ryan Gibbons from Temple University in Philadelphia presented the research of he and his colleagues at ACEP last week. The research presentation was titled “Bedside Ultrasonography for the Detection of Aortic Dissection in the Emergency Department”. You can read the full abstract in the Annals. But here are the essentials:
Methods:
Single centre, Temple in Philly
Jan 2010 to March 2017
Protocol established by Jan 2010 whereby all patients who were suspected of having a dissection and to have a CT got a POCUS scan for PCE, aortic root dilation (cutoff was 3.5 cm at end-diastole) and abdominal aorta scan for an intimal flap.
Results:
442 POCUS scans done
28 patients had dissection on CT, 12 Stanford type A, 16 type B
POCUS found 27 of them
23 of 28 had flap seen, the most common positive finding in the protocol (15 flaps seen among type B)
Only case that POCUS missed was a type B
Sensitivity 96.7% (100% for type A)
Specificity 90.8% (as you know, other diagnoses can lead to a PCE and a dilated aortic root can be a chronic finding)
Of course, a number of limitations. First and foremost, I am summarizing an abstract…can’t wait for the full paper to come out! So some detail is missing…which views were used, did any dissections not have a POCUS scan, was there blinding to the CT result, etc. But that pickup rate is pretty impressive. Of course, future research will be useful to confirm in other centers, perhaps adding to findings from H&P, Dimer, maybe even to come up with a decision rule that adds POCUS as an element 🙂
Here is an example of a dissection flap in the abdominal aorta from one of my colleagues in Sudbury, Dr Virginie Marchadier:
