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Does Spinal Immobilization Help Patients?
It’s just past midnight, and the crew of Medic 4 is called to the scene of a rollover MVC. En route to the scene, dispatch advises the crew that a vehicle has left the road in a stretch of highway well known for motor vehicle accidents, rolling over and coming to rest against some trees. The bystander who called 9-1-1 is on scene and has helped the victim from the car because she “saw some smoke” and “was afraid the car might blow up.”
“Thank God for helpful bystanders,” the medic drawls sarcastically. “What would we ever do without them?
“The smoke was probably airbag propellant,” her partner opines. “They always think the car is going to blow up.”
Upon arrival at the scene, the crew of Medic 4 finds an ambulatory 34-year-old woman with a blanket draped over her shoulders drinking a cup of hot chocolate, both provided by the bystanders, an elderly woman and her husband who live nearby and heard the crash. The vehicle lies on its roof at the bottom of a gentle slope, resting against some pine trees.
The crew’s assessment of the patient reveals little in the way of serious injuries. She has superficial abrasions and cuts from shattered glass, and a small hematoma and laceration on her forehead at the hairline. The woman complains of being “a little stiff and sore,” but winces when her neck is palpated. Sensory, motor and circulatory functions in her extremities are intact. As a precaution, given the cervical spine tenderness, the crew decides to collar and board her.
Several hours later, after they drop off another crash victim, the ED physician informs the crew that the woman had an unstable C2–C3 fracture and was transferred to a nearby trauma center for surgical stabilization of her broken neck. At the time of the transfer, she was still neurologically intact.
“Thank God we immobilized her,” the medic breathes in relief. “She’d have been a quad for sure,” her partner agrees.
The truth is, the crew of Medic 4 has no way of knowing that their attempt to immobilize their patient’s spine contributed in any way to her favorable outcome. In fact, in light of current spinal immobilization research, it is entirely possible the woman had a favorable outcome in spite of their efforts. After nearly two generations of strapping injury victims to spine boards, there is still no evidence of benefit to the practice, and a growing body of research indicates it may do harm.
At best, the studies show no evidence of further harm from spinal immobilization. That’s far from a ringing endorsement for the efficacy of one of our most long-held practices.
The Theory
Spinal cord injury can be categorized into two broad types: primary and secondary. Primary cord lesions are suffered at the time of an accident, and prehospital spinal immobilization does nothing to lessen their severity.
Secondary injury was thought to occur from bony fragments impinging on the spinal cord during excessive manipulation, either causing a new lesion or worsening an existing one. It is these patients, with unstable cervical spine fractures and no neurological deficits, whom prehospital spinal immobilization was meant to benefit.
In theory, prehospital spinal immobilization of these patients was thought to lessen the likelihood of this secondary injury through prevention of excessive manipulation. In reality, that may not be the case.
In fact, what we do in the field isn’t even accurately called immobilization. The current term in vogue is spinal motion restriction, meant to reflect our attempts at limiting spinal movement while recognizing that true immobilization is rarely accomplished. Some researchers even postulate that a conscious victim strapped to an uncomfortable board may be tempted to reposition himself for greater comfort, thus resulting in even more spinal manipulation.
The rate of actual spinal fractures in severe trauma patients is only 2%–5%, and unstable fractures only occur in 1%–2% of severe trauma patients.1–3 Of those, the number of patients with unstable fractures with no neurological deficits—the ones who might presumably benefit from prehospital spinal immobilization—is vanishingly small, only 0.5%–1%.
Given the devastating long-term effects of spinal cord injury, it may be tempting to say, “If it only helps one patient, it’s worth it.” That presumes we are doing no harm to the many thousands of patients who do not benefit from immobilization. But are we?
The Research
To date there has only been one study that compared outcomes in patients who received spinal immobilization with those who received no spinal immobilization. This was a five-year retrospective chart review at two university hospitals that included all patients with acute blunt spinal injury or spinal cord trauma. None of the 120 patients at the University of Malaya, in Kuala Lumpur, Malaysia, were spinally immobilized during transport, and all of the 334 University of New Mexico patients were. The two groups were well matched for neurological injury severity scores, yet the non-immobilized University of Malaya patients had better neurological outcomes (11% vs. 21% disability). The authors concluded that immobilization has little or no effect on neurological outcomes.4 In two separate Cochrane reviews of available research on prehospital spinal immobilization, both authors found no randomized controlled trials that demonstrated evidence of benefit to the practice.5,6
Despite that, we have persisted in strapping curved bodies to flat, rigid boards in the belief that the practice secures the spine in a neutral position. But does it?
In a study of 100 healthy volunteers, a team led by UCLA’s Dr. David Schriger found that immobilization on a long spine board without occipital padding resulted in relative cervical extension for 98% of study subjects.7 They postulated that occipital padding would result in better neutral stabilization and less discomfort. Yet in another study of the effects of neutral positioning with and without occipital padding, a group led by E. Brooke Lerner, PhD, found no significant reduction in pain incidence or severity in subjects immobilized with occipital padding in place.8
It would appear that even among healthy, non-traumatized subjects with necks immobilized in a neutral position, if you do not have neck or back pain before being strapped to a board, you will afterward. This incidence of iatrogenically induced pain complicates assessment in the ED,9 exposing the patient to unnecessary wait times and x-rays, and may linger for days or weeks afterward.
The practice of applying a cervical collar and long board to victims with mechanisms of injury suggestive of cervical spine trauma may produce a number of deleterious side effects, among them reduction in respiratory capacity, pain and discomfort, increases in intracranial pressure, and pressure sores from skin ischemia.10–14 While we may not be able to quantify the degree of harm caused or if it poses any long-term effects, it seems obvious that immobilization does not make these conditions better. In one study of cadavers with surgically created C1–C2 dissociation (internal decapitation), a properly sized cervical collar was found to induce an average of 7.3 mm of distraction between the C1 and C2 vertebrae.15 Some subjects exhibited as much as 11.3 mm—nearly half an inch.
In penetrating trauma patients, Dr. Elliott Haut reported that spinal immobilization attempts were associated with a doubling of mortality rates compared to non-immobilized patients.16 While causality was not determined, it was found that the number needed to treat—unstable spine fractures with no neurological deficits—was 1,032, while the number needed to harm was only 66. Phrased in practical terms, spinal immobilization will harm or kill nearly 16 penetrating trauma patients for every one it helps.
A Better Way?
Most prehospital spinal clearance algorithms are based upon the National Emergency X-radiography Utilization Study (NEXUS) low-risk criteria for blunt trauma. NEXUS was aimed at developing a set of clinical criteria for ruling out cervical spine injury and thus reducing unnecessary x-rays in the emergency department. These criteria are:
• No posterior midline c-spine tenderness;
• No evidence of intoxication;
• Normal level of alertness;
• No focal neurological deficit;
• No painful distracting injuries.
NEXUS was validated in more than 34,000 patients and proved 99% accurate in ruling out cervical spine fractures.17 Contrast these results with the well-known difficulty in ruling out spinal fracture based upon plain cervical spine x-rays, and the validity of the NEXUS criteria becomes evident. In an article on spinal imaging strategies in the European Spine Journal, Paul Parizel and colleagues noted that plain x-ray films detect only 60%–80% of cervical spine fractures, and a significant number of fractures are not visible even when three views of the spine are obtained.18
Using data derived from 8,924 patients enrolled in the Ontario Prehospital Advanced Life Support Study (OPALS), Canadian researchers were able to develop the Canadian C-Spine Rule,19 which identified further high-risk criteria and more specific mechanisms of injury and proved slightly better in both sensitivity and specificity than NEXUS at ruling out cervical spine fractures. Many EMS systems use a hybrid of the two clearance criteria, adding the Canadian determinants of age over 65 and significant injury above the clavicles to the existing NEXUS low-risk criteria. The ability of paramedics to utilize these criteria effectively has been demonstrated in numerous clinical trials.20,21 Maine implemented a statewide c-spine clearance protocol for all levels of EMS providers in 2002. In nearly 32,000 trauma encounters during the study period, 56% were cleared in the field. Of those cleared, only one had an unstable spinal fracture, and that patient suffered no long-term neurological deficits. Sensitivity and negative predictive value for immobilization of an unstable spine fracture were 98.8% and 99.9% respectively.22
Of those very few patients who may benefit from prehospital spinal immobilization, the use of vacuum splints has been demonstrated to provide superior neutral stabilization of the spine and reduce discomfort compared to long boards.23–25 In the past, the use of such devices was considered cost-prohibitive; however, with the advent of rugged full-body splints for roughly $150, that is no longer an excuse.
The Future
It is often said that one should avoid being the first or the last to adopt a new treatment. When it comes to prehospital c-spine clearance, agencies that refuse to adopt the practice are now one generation behind the treatment curve. The debate now is not whether EMTs can effectively determine which patients do not require immobilization in the field, it is whether we should immobilize at all.
Paramedics in Vail, CO, abandoned routine spinal immobilization three years ago. “We looked at the data, and none of it supported routine immobilization,” reports Will Dunn, clinical manager for the Eagle County Ambulance District. “Moreover, what we were doing in the field was totally out of sync with what was being done in the hospital. Here we were, zealously trying to avoid spinal manipulation in everyone, even those we realized were at low risk of spinal fractures, and our hospital was doing active flexion and extension exercises under fluoroscopy to identify suspected cervical spine fractures the x-rays may have missed. It made no sense to keep doing it.”
Dunn reports that patient outcomes have been unchanged in the three years since adoption of the protocol when compared to the previous three years of routine spinal immobilization.
In October 2012, a draft position paper on prehospital spinal immobilization was released by the National Association of EMS Physicians that starkly highlighted current medical thinking on the practice. The NAEMSP believes that:
• There is no evidence that the use of backboards reduces spinal injury or effectively provides anatomically appropriate spinal immobilization or protection.
• There is evidence that backboards result in harm by causing pain, changing the normal anatomic lordosis of the spine, inducing patient agitation, causing pressure ulcers and compromising respiratory function.
• The only practical value of backboards is for extrication to a transport vehicle. Once extricated, patients should be taken off the backboard.
• Backboards should not be used for spinal immobilization. Placing ambulatory patients on backboards is unacceptable.
• In general, patients should not be transported or otherwise kept on backboards for any length of time.
Conclusion
Routine spinal immobilization poses no benefit to the vast majority of our patients and may indeed harm a significant number of them. The ability of paramedics to effectively clear c-spine in the field has been proven in numerous studies. The only question is whether the immobilization we provide does any good at all. Agencies that still routinely perform spinal immobilization cling to an antiquated practice that belongs in the dustbin of EMS history.
References
1. Grossman MD, Reilly PM, Gillett T, Gillett D. National survey of the incidence of cervical spine injury and approach to cervical spine clearance in U.S. trauma centers. J Trauma, 1999; 47(4): 684–90.
2. Lowery DW, Wald MM, Browne BJ, et al. Epidemiology of cervical spine injury victims. Ann Emerg Med, 2001; 38: 12–6.
3. Rhee P, Kuncir EJ, Johnson L, et al. Cervical spine injury is highly dependent on the mechanism of injury following blunt and penetrating assault. J Trauma, 2006; 61: 1,166–70.
4. Hauswald M, Ong G, Omar Z. Out-of-hospital spinal immobilization: its effect on neurologic injury. Acad Emerg Med, 1998; 5: 214–9.
5. Kwan I, Bunn F, Roberts I. Spinal immobilisation for trauma patients. Cochrane Database Systematic Review, 2001; (2): CD002803.
6. Baez AA, Schiebel N. Is routine spinal immobilization an effective treatment for trauma? Ann Emerg Med, 2006; 47: 110–2.
7. Schriger DL, Larmon B, LeGassick T, Blinman T. Spinal immobilization on a flat backboard: does it result in neutral position of the cervical spine? Ann Emerg Med, 1991 Aug; 20(8): 878–81.
8. Lerner EB, Billittier AJ 4th, Moscati RM. The effects of neutral positioning with and without padding on spinal immobilization of healthy subjects. Prehosp Emerg Care, 1998 Apr–Jun; 2(2): 112–6.
9. March JA, Ausband SC, Brown LH. Changes in physical examination caused by use of spinal immobilization. Prehosp Emerg Care, 2002; 6: 421–4.
10. Totten VY, Sugarman DB. Respiratory effects of spinal immobilization. Prehosp Emerg Care, 1999; 3: 347–52.
11. Chan D, Goldberg R, Tascone A, Harmon S, Chan L. The effect of spinal immobilization on healthy volunteers. Ann Emerg Med, 1994; 23: 48–51.
12. Davies G, Deakin C, Wilson A. The effect of a rigid collar on intracranial pressure. Injury, 1996; 27: 647–9.
13. Kolb JC, Summers RL, Galli RL. Cervical collar-induced changes in intracranial pressure. Amer J Emerg Med, 1999; 17: 135–7.
14. Cordell WH, Hollingsworth JC, Olinger ML, Stroman SJ, Nelson DR. Pain and tissue-interface pressures during spine-board immobilization. Ann Emerg Med, 1995; 26: 31–6.
15. Ben-Galim P, Dreiangel N, Mattox KL, Reitman CA, Kalantar SB, Hipp JA. Extrication collars can result in abnormal separation between vertebrae in the presence of a dissociative injury. J Trauma, 2010; 69: 447–50.
16. Haut ER, Kalish BT, Efron DT, et al. Spine immobilization in penetrating trauma: more harm than good? J Trauma, 2010; 68: 115–20, discussion 120–1.
17. Hoffman JR, Mower WR, Wolfson AB, Todd KH, Zucker MI. Validity of a set of clinical criteria to rule out injury to the cervical spine in patients with blunt trauma. National Emergency X-Radiography Utilization Study Group. NEJM, 2000; 343: 94–9.
18. Parizel PM, van der Zijden T, Gaudino S, Spaepen M, Voormolen MHJ, Venstermans C, De Belder F, van den Hauwe L, Van Goethem J. Trauma of the spine and spinal cord: imaging strategies. Euro Spine J, 2010 March; 19(Suppl 1): 8–17.
19. Stiell IG, Wells GA, Vandemheen KL, et al. The Canadian C-Spine Rule for radiography in alert and stable trauma patients. JAMA, 2001; 286: 1,841–8.
20. Vaillancourt C, Stiell IG, Beaudoin T, et al. The out-of-hospital validation of the Canadian C-Spine Rule by paramedics. Ann Emerg Med, 2009; 54: 663–71 e1.
21. 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; 46: 123–31.
22. Burton JH, Dunn MG, Harmon NR, Hermanson TA, Bradshaw JR. A statewide, prehospital emergency medical service selective patient spine immobilization protocol. J Trauma, 2006; 61: 161–7.
23. Luscombe MD, Williams JL. Comparison of a long spinal board and vacuum mattress for spinal immobilisation. Emerg Med J, 2003; 20: 476–8.
24. Johnson DR, Hauswald M, Stockhoff C. Comparison of a vacuum splint device to a rigid backboard for spinal immobilization. Amer J Emerg Med, 1996 Jul; 14(4): 369–72.
25. Hamilton RS, Pons PT. The efficacy and comfort of full-body vacuum splints for cervical-spine immobilization. J Emerg Med, 1996 Sep–Oct; 14(5): 553–9.
Steven “Kelly” Grayson, NREMT-P, CCEMT-P, is a critical care paramedic for Acadian Ambulance in Louisiana. He has spent the past 14 years as a field paramedic, critical care transport paramedic, field supervisor and educator. He is a frequent EMS conference speaker and author of the book En Route: A Paramedic’s Stories of Life, Death, and Everything In Between and the popular blog A Day in the Life of an Ambulance Driver.
William E. “Gene” Gandy, JD, LP, has been a paramedic and EMS educator for over 30 years. He has implemented a two-year associate degree paramedic program for a community college, served as both a volunteer and paid paramedic, and practiced in both rural and urban settings and the offshore oil industry. He has testified in court as an expert witness in a number of cases involving EMS providers and lectures on medical/legal aspects of EMS. He lives in Tucson, AZ.
