Lights and sirens blaze as several ambulances head to a multiple-car freeway accident. When you arrive you see a totaled minivan full of seat-belted children. All are under 8 and appear distraught, though without obvious injury beyond a few abrasions and what you think is a subtle broken arm.
As their mother is trauma-packaged and put into another ambulance, you hear her say they hit another car at highway speed, and she doesn’t remember much more than that. Before helping the kids out of the car, you think to yourself, Did any of these kids hit hard enough to damage their spine?
They’re too young to tell you and be reliable. To be safe you put them all in full spinal immobilization. All the kids start screaming, wriggling, flailing, and trying to rip off the straps. Seeing this you think, Could this possibly be helping?
Spinal immobilization has spurred a long and vigorous debate. Over the past decade the standard degree of immobilization has decreased substantially. Prior to recent research the majority of trauma patients were put into full spinal immobilization with backboard and collar for fear of either missing an occult fracture or damage to the spinal cord during transport.
However, very few trauma patients have any significant neurological injury. While up to 5 million patients are placed in spinal immobilization yearly,1 only 1%–3% of severe trauma patients have cervical fractures, with only 0.4%–0.7% found to be unstable.2 Other research has found that up to 50% of trauma patients without any neck or back pain were placed in full spinal immobilization.3
Given the differing anatomy and limited ability to take a history in young children, it is difficult to apply these same studies to the younger population. Most do not include pediatric patients or sufficient numbers of children. In addition, spinal injury incidence, severity, and characteristics differ substantially among pediatric patients.
There are several key differences in anatomy that alter injury patterns. Young children’s heads are proportionally much larger than adults’. As a result the pivot point in the spine is substantially higher. In addition, the upper segments of cervical spine have significant mobility due to their laxer cervical ligaments, absence of uncinate process, and flatter facets. This increases the risk of subluxation.
With overall smaller anatomy, children also have smaller spinal canals, increasing the likelihood of spinal cord injury with minimal vertebral misalignment. This can lead to spinal cord injury without radiographic abnormality (SCIWORA)—neurological deficits or neurogenic shock occurring in the first four days after trauma without bony abnormalities found on plain radiographs or computed tomography imaging. Finally, the ossification of the second cervical vertebral body puts the dens at particular risk. These anatomical differences evolve into largely adult anatomy by age 8.4
Thus for children under 8, cervical injury commonly occurs in higher portions of the cervical spine, leading to severe damage with higher rates of mortality. In one study looking at pre-elementary trauma patients, the median injury severity score was 33, with 50% mortality.5 On the other hand, this increased severity makes asymptomatic cervical injury rare in young children. Of the almost 3,000 pediatric traumas reviewed, only 22 (0.74%) had cervical spine injuries, and all had recognizable clinical findings.
Overall rates of significant spinal cord injury are very low in both children and adults, leading to overutilization of immobilization. Spinal precautions over the past 50 years have ranged from total immobilization with full backboard and collar to soft cervical collars. A systematic Cochrane review found no quality studies that compared the effectiveness of varying methods of immobilization and reported an overall “lack of data from randomized controlled trials to support the practice of prehospital spinal immobilization in trauma patients.”6
In addition, without any clear difference in neurological outcomes, numerous countries refrain from any spinal immobilization at all. One study compared spinal injury patients in Malaysia, where there is no spinal immobilization, to New Mexico, where all patients were immobilized. The authors found neurological outcomes were significantly worse in the New Mexico population. (However, there were no injury severity scores to compare between sites, and New Mexico had a significantly high proportion of injuries secondary to motor vehicle accidents.7)
Risks and Harm
Evidence also shows several areas of well-studied adverse effects from backboard immobilization. Even in healthy adults backboards can damage sacral tissue within 30 minutes.8 Furthermore, immobilization can cause respiratory compromise as well as unnecessary imaging. In particular in children, the use of a backboard has been linked to increased pain, imaging, and admissions in a case cohort with patients of similar injury severity scores and GCS.9 There is also evidence to suggest patients with penetrating trauma have substantially increased mortality if immobilized.10 Thus it is no longer required or recommended to immobilize patients on backboards given that the adverse effects outweigh the benefits.11
Universally there are low rates of significant spinal cord injury, especially in young children, along with proven negative outcomes with hard backboards. Furthermore, prehospital providers rarely miss significant injuries. A small study in New Mexico found none of the 101 patients who were placed in cervical spine immobilization on arrival at the emergency room after being cleared by EMS had acute cervical spine injury.12
Other selective spine immobilization protocols around the country have proven to be between 92%–99% sensitive, with almost no adverse outcomes or spinal cord injury in those missed.13,14 While these protocols were slightly different, they helped change the overall implementation of spinal immobilization by taking mechanism of injury out of the protocol. Current guidelines from the American College of Emergency Physicians, based on NEXUS (National Emergency X-Radiography Utilization Study) results, recommend considering cervical stabilization based on altered mental status or intoxication, midline spine pain, focal neurological symptoms, or obvious deformity or distracting injury.15
Again, these studies either do not include children or have so few that they are not powered to include them in clinical decision rules. One study using the national PECARN network looked at 540 children with cervical spine injuries compared to age- and mechanism-matched controls and developed a decision rule that was 98% sensitive.16 These eight factors included altered mental status, focal neurological findings, neck pain, torticollis, substantial torso injury, conditions predisposing to cervical spine injury (like Down syndrome), diving, and high-risk motor vehicle crash. It has yet to be externally validated but is the first step in developing a rule to avoid unnecessary cervical spine stabilization.
Evidence shows emergency providers often cause iatrogenic harm with full prolonged spinal immobilization without any clear research to indicate efficacy. On the other hand, there is minimal evidence to guide isolated cervical spine stabilization. Studies have questioned the overall efficacy of cervical collars in adequately minimizing movement. Research with healthy volunteers shows limitations in movement with collars,17 while a study with cadavers given unstable cervical spines displayed ineffective reduction in mobility.18 An early study in the pediatric population also found cervical collars alone were ineffective at reducing mobility.19
Similar to rigid backboards, cervical collars are not without risks. They have been found to increase intracranial pressure as well as interfere with respiratory function.20 In addition they are poorly tolerated in uncooperative and agitated patients. A study looking at healthy pediatric volunteers noted that “live subjects were unable to cooperate in testing even a few collars.”21 As a result recent Norwegian guidelines recommend that rigid collars should not be used routinely and should be avoided in “traumatic brain injury, airway compromise, ankylosing spondylitis, or agitation.”22
In addition, the impact of stabilization on further damage to the spine is questionable. The University of New Mexico’s Mark Hauswald, MD, evaluated the force required for injury and found that approximately 2,000–6,000 newtons are required to fracture the cervical spine, while an average-size head only induces around 40 newtons of force.23 He thus argued that simple movements of the spine do not have enough force to induce further damage.
Clinically significant cervical spine injuries in adults and children are rare. Given anatomic differences in children under 8, severe injuries are more common, and asymptomatic injuries are largely absent in the literature.
Over the past 50 years, emergency providers have deescalated spinal immobilization in both patient populations given evidence that hard backboards may worsen outcomes and cause injury to other systems. There are numerous studies to help stratify risk of cervical spine injury in adults and very few in children. At the same time, providers still likely overutilize immobilization techniques, leading to unnecessary escalations in care.
Evidence-based medicine has improved the largely dogma-based protocols of the 1960s. However, research has failed as of yet to tackle the efficacy, risks, and benefits of cervical spine immobilization, especially in children.
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3. McHugh TP, Taylor JP. Unnecessary out-of-hospital use of full spinal immobilsation. Acad Emerg Med, 1998; 5: 278–80.
4. Huerta C, Griffith R, Joyce SM. Cervical spine stabilization in pediatric patients: Evaluation of current techniques. Ann Emerg Med, 1987 Oct; 16(10): 1,121–6.
5. Hale DF, Fitzpatrick CM, Doski JJ, et al. Absence of clinical findings reliably excludes unstable cervical spine injuries in children 5 years or younger. J Trauma Acute Care Surg, 2015 May; 78(5): 943–8.
6. Kwan I, Bunn F, Roberts I. Spinal immobilization for trauma patients. Cochrane Database Syst Rev, 2001; (2): CD002803.
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8. Berg G, Nyberg S, Harrison P, et al. Near-infrared spectroscopy measurement of sacral tissue oxygen saturation in health volunteers immobilized on rigid spine boards. Prehosp Emerg Care, 2010 Oct–Dec; 14(4): 419–24.
9. Leonard JC, Mao J, Jaffe DM. Potential adverse effects of spinal immobilization in children. Prehosp Emerg Care, 2012 Oct–Dec; 16(4): 513–8.
10. Haut ER, Kalish BT, Efron DT, et al. Spine immobilization in penetrating trauma: More harm than good? J Trauma, 2010 Jan; 68(1): 115–20, discussion 120–1.
11. National Association of EMS Physicians, American College of Surgeons Committee on Trauma. EMS spinal precautions and the use of the long backboard. Prehosp Emerg Care, 2013 Jul–Sep; 392–3.
12. Tello RR, Braude D, Fullerton L. Froman P. Outcome of trauma patients immobilized by emergency department staff, but not by emergency medical services providers: A quality assurance initiative. Prehosp Emerg Care, 2014 Oct–Dec; 18(4): 544–9.
13. Domeier RM, Frederiksen SM, Welch K. Prospective performance assessment of an out-of-hospital protocol for selective spine immobilization using clinical spine clearance criteria. Ann Emerg Med, 2005 Aug; 46(2): 123–31.
14. Stroh G, Braude D. Can an out-of-hospital cervical spine clearance protocol identify all patients with injuries? An argument for selective immobilization. Ann Emerg Med, 2001 Jun; 37(6): 609–15.
15. American College of Emergency Physicians. EMS Management of Patients With Potential Spinal Injury. EMS World, https://www.emsworld.com/news/12052931/acep-ems-management-of-patients-with-potential-spinal-injury.
16. Leonard JC, Kuppermann N, Olsen C, et al. Pediatric Emergency Care Applied Research Network. Ann Emerg Med, 2011 Aug; 58(2): 145–55.
17. Rosen PB, McSwain NE Jr., Arata M, et al. Comparison of two new immobilization collars. Ann Emerg Med, 1992 Oct; 21(10): 1,189–95.
18. Horodyski M, DiPaola CP, Conrad BP, Rechtine GR 2nd. Cervical collars are insufficient for immobilizing an unstable cervical spine injury. J Emerg Med, 2011 Nov; 41(5): 513–9.
22. Kornhall DK, Jorgensen JJ, Brommeland T, et al. The Norwegian guidelines for the prehospital management of adult trauma patients with potential spinal injury. Scand J Trauma Resusc Emerg Med, 2017 Jan 5; 25(1): 2.
23. Hauswald M. A re-conceptualisation of acute spinal care. Emerg Med J, 2013 Sep; 30(9): 720–3.
Chelsea Williams, MD, MPH, is in her final year of emergency medicine residency at Barnes-Jewish Hospital/Washington University in St. Louis. She is a graduate of the Northwestern University Feinberg School of Medicine. She plans to pursue a fellowship in global health after graduation from residency.
Hawnwan Philip Moy, MD, is an assistant medical director for the St. Louis City Fire Department and emergency medicine clinical instructor and core faculty in the EMS Section of the Division of Emergency Medicine at Washington University in St. Louis. He completed his emergency medicine residency at Barnes-Jewish Hospital/Washington University and his EMS fellowship at the
University of North Carolina in Chapel Hill.