For many years, ATLS has dictated cervical collar as part of the A in ABC, and any patient that enters a trauma bay gets a cervical collar slapped on before anyone cares about airways, breathing and circulation. The last couple of years, some rougue docs have tried opposing the validity of the extreme focus on cervical collars, and it is finally starting to trickle into the system. Here’s the case against cervical collars – and for bringing the focus back on the important parts of the ABC to save your patient.
The cervical collar dogma
The cervical collar has become a curse. It’s seen as the shining proof of good quality trauma care. No ambulance service dare deliver a patient to a trauma bay without a cervical collar. Not based on trauma mechanism or patient symptoms, but solely based on fear of criticism from the in-hospital ATLS-trained trauma team leader. Don’t get me wrong, ATSL has done a lot of good – but it can also be slow to adapt to new trends, and implement interventions in a dogmatic way instead of patient case based. Knowing ATLS is not an excuse to stop thinking.
This takes us to the case of the cervical collar. One main article to look at is a review article in the Scandinavian Journal of Trauma by Benger et al that points to four myths of the cervical collar:
1. Injured patients may have an unstable injury of the cervical spine.
2. Further movement of the cervical spine could cause additional damage to the spinal cord, over and above that already caused by the initial trauma itself.
3. The application of a semi-rigid cervical collar prevents potentially harmful movements of the cervical spine.
4. Immobilisation of the cervical spine is a relatively harmless measure, and can therefore be applied to a large number of patients with a relatively low risk of injury “as a precaution”.
Myth 1: Injured patients may have an unstable injury of the cervical spine.
Of course, trauma patients may have an unstable cervical spine injury. But the incidence seems to be low. In two studies on trauma patients who were considered at high risk of head and neck trauma, they found an incidence of 0,7% for significant cervical spine injury.
Myth 2: Further movement can cause additional injury.
Neurology can worsen after the initial accident, but is neck movement to blame? Edema and bleeding can surely attribute. But additional movement? In the awake patient, it seems like the patient will protect his own spine, just as he would protect a broken arm by automatically holding it still, and any tissue trauma and swelling will only help stabilise the area, even in the unconscious patient. And carefully moving the unconscious patient or carfully manipulating the neck is unlikely to cause more harm. In a patient cohort with confirmed cervical vertebral injury, 8% of them did not have their spine immobilised – but outcome did not differ.
In a study comparing the incidence of neck injuries in a first world country where cervical collars are applied, to a third world country without collars, there was no difference in the incidence of neurological injuries from the cervical spine. There are many flaws with such a study, but if we expected a big rise in secondary spine injuries, it should have been detected in these smallish samples.
Myth 3: The cervical collar restricts neck movement.
This is one of the big ones. Everyone who’s worked with trauma patients know the collar doesn’t stabilise the neck much. Even a perfectly apllied collar allows for at least 30 degrees of flexion/extension/rotation.
OK, OK, so spinal injuries aren’t that common, cervical collars don’t really immobilise the neck, and collars have never been proven to affect clinical outcome – but how about we just put the collar on anyway, to be on the safe side… It sure couldn’t do any harm?
Myth 4: Just put on the collar anyway, to be on the safe side…
But is the cervical collar safe? Due to its pressure on the jugular veins and reduced venous return, it increases ICP. Not so good on an unconscious head trauma patient… But the patients with an actual cervical spine fracture – surely the collar will help these patients? In a cadaver study where they inflicted neck injury on the cadavers and then place a semi rigid collar around the neck, radiological studies showed that the collar increased the fracture crease by over 7 mm! The conclusion was that a cervical collar on these patients probably would have made the neck injury worse. Oops. Then there’s the airway management. The collar hampers airway management, and is also a big aspiration risk for a vomiting patient.
So, where’s the upside?
On the pro collar side, there doesn’t seem to be any evidence available to support the use of cervical collars, the upside seems to be largely theoretical. Benger thinks cervical collars should only be applied in an unconcious patient where you have a high degree of suspicion for cervical spine fracture. But one could easily make the argument that the cervical collar shouldn’t be used in these patients either – or in any other patients. Patients where you think cervical spine stabilisation is warranted, supporting the head with a few blankets or similar might be better – and will avoid the raised ICP and dislocated fracture.
The collar we put on millions of trauma patients every year has no proven benefit, no proven protection against secondary injuries. Still, we put it on with the A in ABC and take focus and time from more important interventions. For the patient with a high suspicion of spine injury, careful handling is needed – but not a cervical collar. For all other trauma patients, they will more than likely be better off without the collar. The HEMS service in Bergen has started delivering more and more trauma patients to the trauma bay without a cervical collar – and the counter-revolution has just started.
This post was put together from several articles and also much based on a Norwegian presentation and short article from Dr. Helge Asbjørnsen, consultant anaesthetist in the Norwegian HEMS service. So a big thanks to my colleague Helge. His Norwegian article is linked to in full text below.
For Scandinavian readers, Helge Asbjørnsen’s article on cervical collars in Norwegian is a must:
“Har noen behov for – eller nytte av – nakkekrage?”