One of the changes that I’ve promoted as medical director is a movement away from spinal immobilization (rigid spine board + hard cervical collar) to other forms of spinal motion restriction, including patient coaching, use of vacuum mattress, toboggan, and gurney as immobilizing surfaces, as well as alternative methods of head securement.

The reason for this change is based largely on a joint position statement from the National Association of EMS Physicians (NAEMSP), American College of Surgeons Committee on Trauma (ACS-COT), and the American College of Emergency Physicians (ACEP) published in 2018. This brilliantly concise and legible document highlights that a greater variety of tactics can be employed to reduce unwanted motion in the injured spine than just a hard board and collar, and that any of the tactics that we employ don’t really immobilize the spine, they just reduce motion. Thus the shifting terminology.

I’m always on the lookout for new or better information to inform what we do, so I was very happy when Nancy Pietroski of NSP sent me an article from the WMS magazine on spinal motion restriction. The article makes for good casual reading on the history of spinal immobilization and the evolving literature on the subject, if you’re interested. The article cites an important piece of work from NAEMSP that I was previously unaware of, and the results of which I want to share. Prehospital Trauma Compendium: Prehospital Management of Spinal Cord Injuries – A NAEMSP Comprehensive Review and Analysis of the Literature is a comprehensive review of the available evidence conducted by NAEMSP to answer 4 patient oriented questions. Importantly, their literature search and review process was good, and they screened 3944 articles, reviewed 769 full manuscripts, and ultimately analyzed 115 articles fully to inform their review. For each of their questions, I’ll summarize what they found. I’ve taken the liberty of making each of their questions more legible to the reader.

For the already-bored reader, you can jump to the takeaway at the bottom for the Cliff’s Notes.

What are the causes of delayed neurological injury in trauma patients?

Focus: on movement, hypoxia, hypoperfusion.

There isn’t any quality evidence showing that movement of a trauma patient with spinal injuries results in worse neurological outcomes. The dogma that it can came from two very crummy reports in the early 20th century that quickly became unexamined dogma.

In contrast, there’s greater evidence that low blood pressure after an initial injury can result in worsened neurological injuries. These studies are much more rigorous.

A few example findings are that:

A) a 10mmHg increase in prehospital MAP led to a 79% increase in the odds of a patient have an improved neurological outcome, with benefit see at around a MAP of 85mmHg.

B) Fewer prehospital hypotensive events led it improved neurological recovery at one year.

Does using a backboard or cervical collar harm patients?

Focus: on pressure ulcers, respiratory problems, increased intracranial pressure, or direct harm to the nervous system.

Many studies were identified showing that even brief use of spine board or C-collar alone were associated with the development of pressure injuries. This may also apply to vacuum mattresses.

C-collars also make it harder to breathe and can cause respiratory obstruction in unconscious patients. Again, the vacuum mattress doesn’t seem to prevent such issues.

Increased intracranial pressure (ICP) is also associated with C-collar use. This is a problem in anyone with bleeding or swelling in the brain, as blood flow to brain tissue is essentially blood pressure (MAP) minus ICP.

C-collars definitely make certain kinds of C2 fractures worse, and can also hide significant traumatic injuries to the trachea.

Lastly, and not surprisingly, c-collars and backboards increase pain/discomfort and result in increased use of radiology studies when patients arrive in the hospital.

Do backboards and cervical collars prevent neurological injury or reduce spinal motion as intended?

In short, probably not. The one paper identified that showed a benefit to spinal immobilization failed to control for a lot of other variables and had methodological flaws. If anything, it supported use of cervical calls in patients with a cervical cord injury and a high trauma severity score (ISS >9).

Quite a number of other better studies were identified showing either no change to neurological deficits or worse neurological deficits with immobilization.

9 studies showed increased movement of the spinal column with immobilization, 6 showed no effect, and 11 showed reduction in spinal movement with immobilization.

Quite a few studies showed no effect on neurological deficits to withholding immobilization, and no increase in delayed injury in patients without cervical collars even in those found to have cervical spine injuries.

Studies examining shifts towards eliminating backboards and focusing on SMR showed no ill effects.

Are there other factors that could influence the usefulness of backboards and cervical collars?

Focus: patient anxiety, age anatomy, environmental conditions.

C-collars distort anatomy in pediatric patients.

Old people spend more time in cervical collars once they’re on and are at risk of developing swalling difficulties and respiratory failure.

No other factors were identified.

My Takeaway

…is that even the 2018 joint policy statement may be too aggressive in recommending spinal motion restriction.

There isn’t good evidence that post-injury motion can be harmful to patients, or that spinal immobilization is able to reduce such harm. However, there is good evidence that hard boards, cervical collars, and even vacuum mattresses can cause harm.

The literature review here is all based on retrospective and observational data, so it isn’t strong enough evidence to really change practice yet, but I do think it opens the door to a clinical trial that could be the end of backboards or cervical collars.

I think that we can use these touchstones for now

• We should minimize movement to the spine in cases when a spinal injury should be present, but we should think more broadly about motion minimization to include well-padded flat surfaces like toboggans and coaching patients to minimize motion of their head.
• We should treat long spine boards, scoops, and even vacuum mattresses as extrication tools. These remain useful to us as our toboggan ride is extrication from the mountain environment and is pretty prone to motion. Once in clinic or ambulance, we should try to remove the patient from the board or vacuum matterss to minimize harm.
• We should be mindful of blood pressure in our trauma patients and treat hypotension.
• Vacuum mattresses shouldn’t be thought of as safer spinal immobilization, though they are definitely more comfortable and should be used in place of hard boards when reasonable. They do remain excellent tools for splinting the whole body in patients with multiple traumatic injuries, so we’re not going to throw them out with the hard plastic spine boards.
• We should be prepared to continually reexamine our spinal motion restriction practices and be prepared to change in the future as more and better evidence becomes available.

Your thoughts?

PF