There's little in EMS more automatic than applying cervical collars to patients with possible neck injuries. That doing this might in some cases harm them is a horrifying prospect. But that's an implication raised by research published earlier this year by the Journal of Trauma.
A team led by Baylor University orthopedist Peleg Ben-Galim, MD, found that using extrication collars in the presence of severe dissociative neck injuries can result in abnormal separation within the upper cervical spine. On cadaver models with recreated c-spine injuries, collars produced a separation of 7.3 +/- 4.0 mm between C1 and C2.
"Cervical extrication collars are put on about 15 million times a year…to protect the cervical spine in case of a bad injury," co-investigator John Hipp, PhD, director of Baylor's Spine Research Lab, said in announcing the findings. "It is known that after a person has a bad injury, you can create a secondary injury very easily. We have discovered that the cervical collar, in the case of a really bad injury, not only doesn't protect the spine, but can actually make things a lot worse."
The cadaver recreations were based on real cases. Researchers cut the bodies' neck ligaments and membranes but left supporting musculature, then captured images by x-ray, fluoroscopy and/or CT scan before and after application of a rigid collar and some typical patient maneuvers. Distraction was clearly visible--the collar consistently pushed the head up and away from the shoulders. In a living patient with unstable cervical anatomy, this could contribute to secondary injury--or worse.
What this means for EMS, though, probably isn't all that much yet. It's certainly not enough to send systems out changing standards of care. C-collars remain appropriate and safe for most of the patients on whom they're used. But there are definitely some things we should take from these findings.
"It's a call to bring everyone back to the basics," says Houston Fire Department Medical Director David Persse, MD, EMT-P, FACEP, who spoke on the data at the Gathering of Eagles conference. "When people have cervical spinal injuries, the neck by definition is unstable, so as you care for that patient, you need to make sure you move that neck as little as possible. With internal decapitation injuries, contrary to what some may believe, not all patients die before EMS arrives on scene, and a few actually survive to the hospital. That makes it important that we either identify them in the field, or at least care for them properly."
It's worth noting that the types of injuries examined here would typically be fatal in the field. However, fluoroscopy has documented the same effect on a living patient with a high cervical injury, and dissociation need not be complete for additional spinal cord trauma to occur.
So EMS needs to be vigilant about the neck. The difficulty is that severe neck injuries are often accompanied by substantial other trauma. Victims will likely have other injuries that demand providers' attention. And, more difficult still, if our current methods of c-spine immobilization are suboptimal, then what? What should we use instead?
For now, if you're a concerned chief or medical director, it's a call to emphasize technique. The purpose of collars is to minimize movement of the head and neck. Hard collars may not do that much better than soft collars and head blocks--as the Baylor team showed, even a correctly sized collar can allow a slight lateral wobble when a board tilts. Providers must also guard against any tendency, when holding stabilization on the head, to unconsciously provide gentle traction.
"We need to be smarter than the problem," says Persse. "Our guys need to be aware, when they come across somebody who's in a rapid-deceleration injury or fall or whatever, of paying attention to the neck. You want to try to have and keep the head in a neutral position. Depending on circumstances, there may be half a dozen different ways to do that, but the goal is a neutral position, and not to be distracting."