In my last post, I described the evolution of the classic approach to penetrating neck injury. Today, I’ll propose a new way of managing it based on a combination of physical exam and CT scan.
This proposal is based on the high degree of accuracy that CT angiography of the neck provides. It is very sensitive for identifying even small injuries to the aerodigestive tract and vascular system. This study is based on work done at LA County – USC Hospital several years ago.
The trauma group at LAC+USC organized a prospective, multicenter study using a multidetector CT angiography of the neck for initial screening of penetrating neck injury. This allows evaluation the neck as a single unit, not as three zones. It also solves the problem of trying to apply zones to injuries that cross several of them.
The new algorithm that was tested utilized an initial physical exam, first looking specifically for “hard signs” of injury. The following were considered the hard signs:
- Active hemorrhage
- Expanding or pulsatile hematoma
- Bruit or thrill over the injured area
- Unresponsive shock
- Hemoptysis or hematemesis
- Air bubbling from the wound
These patients were immediately taken to the OR and explored through an appropriate incision.
Patients with no signs or symptoms were admitted and observed for at least 24 hours. All other patients were considered to have “soft signs.” They underwent multidetector CT angiography of the neck, with a scanner having at least 40 slices. Further evaluation of these patients was based on the exam and CT scan.
Here are the factoids:
- 453 patients with penetrating neck injury were identified during the 31 month study period
- 9% had hard signs and were taken to OR; 50% had soft signs are underwent CT; 41% had no signs and were observed
- For soft sign patients, 86% of scans were negative and all were true negatives after observation
- 12% of soft sign patients had a positive scan, and of those 81% were true positives
- 4 patients (2%) with soft signs had too much artifact for an accurate CT and other tests were performed; 1 of the 4 had an injury
- Sensitivity of CTA was 100% and specificity was 97.5% in the soft sign patients
- The authors concluded that CTA is very reliable for identifying injuries in patient with soft signs, and that patients with no signs do not require scanning, only observation
Bottom line: This is an intriguing paper that takes advantage of both physical examination at CT angiography. The results are impressive, but the numbers are still relatively small. It lends support to the argument that CTA is not required in all stable patients. But I can’t recommend completely changing our practice yet based on this one study. Additional numbers are certainly needed, but I suspect that this will become the norm in the future. I would also recommend that we all carefully look at our diagnostic algorithms to see other areas where we might identify and eliminate unneeded imaging, labs, etc.
Reference: Evaluation of multidetector computed tomography for
penetrating neck injury: A prospective multicenter study. J Trauma 72(3):576-584, 2012.