Blunt carotid and vertebral artery injuries (BCVI) are an under-appreciated problem after blunt trauma. Several screening tools have been published over the years, but they tend to be unevenly applied at individual trauma centers. For an unfortunate few, the only indication of BCVI is a stroke while in hospital.
The overall incidence of BCVI is thought to be small, on the order of 1-2%. But how do we know? Well, the group at Birmingham retrospectively reviewed every CT angiogram (CTA) of they did in a recent two year period. They did this after adopting a policy of screening all their major blunt trauma patients. Each patient chart was also evaluated to see if they met any of the criteria for the three commonly used screening systems.
Here are the factoids:
- 5,634 of 6,800 blunt trauma patients underwent BCVI screening with CTA of the neck
- 471 patients (8.4%) were found to have BCVI
- Here are the accuracy statistics for the three screening systems
Here are my comments: The authors found that the incidence of BCVI is about 8x what we previously thought. What we don’t know is the percentage of these patients that go on to cause stroke or other neurologic deficits. But this is somewhat frightening.
Even more frightening is that the screening systems that we rely on fare so poorly. The Denver and Modified Memphis criteria have a true positive rate that is the same as a coin toss. And even if the patient meets none of the criteria in any system, about 5% BCVI will sneak through (NPV 95%).
So the question becomes, do we all perform universal screening for blunt trauma? Or do we still use one of the three systems and keep our fingers crossed that the ones we miss will not progress? Or maybe just give everybody an aspirin a day for a while. And still keep our fingers crossed!
Here are some questions for the presenter and authors:
- Why did you decide to implement a universal screening protocol in the first place? Bad experience(s)?
- Do you have any screening recommendations other than to screen everybody? How do you decide which blunt trauma patients to screen? Every car crash? What level of fall? The devil is in the details!
This is an easy to follow paper with a solid analysis and real world implications. Excellent work!