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Cervical collars have long been the 'golden rule' for neck protection in trauma patients.
Recent literature has questioned this dogma.
Below is a selection of articles looking at this question.
This is really the article that got the whole topic going as to whether C-Spine collars and backboards should be used.
J Neurotrauma. 2014 Mar 15; 31(6): 531–540.
Prehospital Use of Cervical Collars in Trauma Patients: A Critical Review
Terje Sundstrom, Helge Asbjornsen et al
The cervical collar has been routinely used for trauma patients for more than 30 years and is a hallmark of state-of-the-art pre-hospital trauma care. However, the existing evidence for this practice is limited: Randomized, controlled trials are largely missing, and there are uncertain effects on mortality, neurological injury, and spinal stability. Even more concerning, there is a growing body of evidence and opinion against the use of collars. It has been argued that collars cause more harm than good, and that we should simply stop using them. In this critical review, we discuss the pros and cons of collar use in trauma patients and reflect on how we can move our clinical practice forward. Conclusively, we propose a safe, effective strategy for prehospital spinal immobilization that does not include routine use of collars.
Cervical collars are considered important measures in modern pre-hospital trauma care. The recommended practice of routine application of collars in trauma patients has largely been unchanged for more than 30 years. It is featured as a prioritized procedure in the Advanced Trauma Life Support (ATLS) guidelines from the American College of Surgeons (ACS)1 and the Pre-hospital Trauma Life Support (PHTLS) guidelines from the National Association of Emergency Medical Technicians (NAEMT). These guidelines dominate the field of pre-hospital trauma care, and ATLS and PHTLS are implemented in 50–60 countries. The use of collars is, in fact, regarded as so important that it is highlighted in the well-known ABCs of major trauma as a first measure, together with establishment of free airways.
Collars were introduced to prevent secondary injury to the spinal cord by immobilizing a potentially unstable spine. Many years have passed since, and this practice has evolved into a hallmark of modern state-of-the-art prehospital care. Millions of trauma patients are currently fitted with a collar every year. However, as evaluated in a Cochrane review in 2001 (updated in 2007), the documented evidence for our ongoing practice is rather limited: Randomized, controlled trials (RCTs) are largely missing, and there are uncertain effects on mortality, neurological injury, and spinal stability. Moreover, and perhaps more concerning, there is a growing body of evidence and opinion against the use of collars.
Improving prehospital management has a substantial effect on society as a whole and is a high-priority research area. In this review, we argue that it is time to reconsider the unjustified dogma of collar use in prehospital trauma care.
We performed a literature search in the Medline database using a combination of relevant medical subject headings (MeSHs) and text words: (“cervical vertebrae”[MeSH] or “neck”[MeSH] or cervical[text word]) and (“braces”[MeSH] or collar*[text words] or “immobilization”[MeSH]) and (“wounds and injuries”[MeSH] or “emergency medical services”[MeSH]). This search was limited to human studies in English available by April 2013. All authors contributed to the search strategy development. We found 1018 publications, of which 88 titles were considered relevant by one or two independent authors (T.S. and K.W.). Borderline titles were included. These publications underwent full review by the author group, and 50 articles were found relevant to prehospital use of collars in trauma patients by more than one author. These articles are included here. Finally, we searched the reference lists of retrieved articles and contacted experts in the field to identify pertinent studies. Articles published over the last 10–15 years were prioritized.
Epidemiology of Cervical Spine and Spinal Cord Injuries
Several reports state that approximately 2–4% of trauma patients have cervical spine injuries (CSIs), of which roughly 20% have spinal cord injury (SCI), 10% have multi-level injuries, and 10% have pure ligamentous injuries. The majority of patients with CSIs have injuries to other body regions, most frequently the head, chest, and extremities. The reported rate of delayed diagnosis or missed CSI is very low (1.3% of all cervical injuries). CSIs are more often observed in unconscious or obtunded patients than in those that are alert and communicable.
The incidence of hospital-admitted cervical fractures in the general population was recently estimated at approximately 12 in 100,000 per year in a prospective observational cohort study. Incidence increased with increasing age. Twenty-seven percent of patients in this cohort were operated on, 68% were treated with collars, and 5% did not receive any specific treatment. Approximately 80% of the patients had a normal neurological status at the time of diagnosis. The most common trauma mechanisms were falls (60%) and motor vehicle accidents (21%). In this study, Fredø and colleagues found a strong association between cervical fractures and traumatic brain injuries (TBIs), with 11% of patients having a moderate to severe TBI and 78% having a minimal to mild TBI.
Over the past 40 years, there has been a shift in functional outcome for patients with SCIs in Western countries: The percentage of incomplete tetraplegia has increased, whereas complete paraplegia or tetraplegia has decreased. Survival after SCI is strongly related to the extent of neurological impairment, and several studies have shown increasing survival rates and life expectancy. These improvements in outcome can, for the most part, be attributed to systematic injury prevention strategies (e.g., education, legislation, and safety features of cars), rather than the implementation of evidence-based treatment guidelines, advances in emergency medical services (EMS), improvements in neurocritical care, or establishment of regional trauma centers. The mean age of CSI and SCI patients has increased, and this has important implications for treatment and outcome. Epidemiological trends and causality analyses in CSI and SCI are very similar to those observed in the related field of TBI.
The American Association for Neurological Surgeons (AANS) and the Congress of Neurological Surgeons (CNS) Joint Guidelines Committee recently published a comprehensive update of the Guidelines for the Management of Acute Cervical Spine and Spinal Cord Injury. These guidelines provide 112 evidence-based diagnostic and treatment recommendations (77 level III, 16 level II, and 19 level I recommendations). The vast majority of treatment recommendations are level III, and all surgical recommendations, except one level II for type II odontoid fractures, are level III recommendations.
In the pre-hospital setting, the AANS/CNS recommends spinal immobilization of all trauma patients with a known or suspected CSI or SCI; however, experienced personnel should evaluate the need for immobilization during transport (level II). Fully awake and communicable patients that are not intoxicated, without neck pain or tenderness, neurologically intact, and without distracting injuries should not be immobilized (level II). The preferred method of immobilization is the combination of a rigid collar and supportive blocks on a spine board with straps (level III). Sandbags and tape alone should not be used, and spinal immobilization in patients with penetrating trauma is not recommended (level III).
The AANS/CNS guidelines are generally in line with the ATLS and PHTLS guidelines as well as other reviews and management guidelines for CSIs, and they all state that collars are effective in limiting motion of the cervical spine and should therefore be used until the patient is properly assessed and the cervical spine is cleared.
Why Do We Use Cervical Collars? Looking Outside the Guidelines
CSIs are feared because of the inherent risk of permanent SCI with potential life-threatening and -changing consequences for patients. Moreover, there are important concerns about medicolegal liability, although not yet prevalent in Scandinavia; malpractice lawsuits in cases of avoidable SCI are very expensive, with compensations of approximately $3 million USD. Further, collars are generally regarded as safe and effective, and few question their use in daily trauma practice; it makes good sense to stabilize an unstable injury. Collars have essentially become a symbol of high-quality trauma care, and in many EMS systems protocolized paramedics never deliver patients without a collar to the emergency department (ED). Besides, the ABCs of major trauma is a powerful mnemonic and a strong psychological premise for medical action in the field. Finally, and essential in this regard, it is better to have a protocol than no protocol, and it is better and cheaper to advocate an easy, uniform practice than a difficult, individualized one.
How Effective Are Cervical Collars?
It has been postulated that 3–25% of SCIs are secondary, occurring either during pre-hospital or early hospital care, and are the result of “inappropriate management,” such as lack of spinal immobilization (as frequently cited previously). This claim has, however, a number of limitations. First, it is not easy to identify a neurological decline throughout the pre-hospital phase. Second, extrapolation of results obtained in a hospital setting to the pre-hospital arena is questionable. Third, several of the cited studies were conducted many years ago with other treatment standards and available resources, so it is not always clear which factors really contributed to the clinical worsening, and there are significant concerns as to the evidence-based value of case series. Moreover, it is essential to understand that approximately 5% of patients with spinal injuries experience some degree of neurological worsening, even with good immobilization of the spine. This clinical deterioration can be the result of well-known mechanisms, such as hematomas, edema, hypotension, hypoxemia, or inflammation.
The collar should, in theory, protect patients from secondary spinal cord traumas by restricting inadvertent movements of unstable CSIs. However, we will probably never know how many secondary SCIs collars have prevented. Collar efficacy on motion control has never been examined in real trauma patients. There are also no RCTs that address the effect of collars on outcomes after CSI and probably never will be. Conversely, a number of studies have examined spine movement in simulated environments (e.g., cadavers with or without rigor mortis or healthy volunteers) using a wide range of devices and assessment criteria, and the results of these studies are somewhat contradictory and confusing. For instance, studies have shown that collars can be placed and removed without large displacements, a rigid collar can increase movement in the upper cervical spine, there is similar restriction in cervical range of motion using soft and rigid collars, there is less motion with a collar in place than without a collar, using a collar does not effectively reduce motion in an unstable spine, there is no extra motion control by adding a collar to a spine board with head blocks, a collar and spine board provide more immobilization than a collar alone, a collar and a vacuum mattress offer greater stability and comfort than a collar and a spine board, immobilization provided by the short board is superior to collars and not augmented by adding collars, sandbags, collar, and tape is the most effective measure for motion control (the use of sandbags is limited though because of practical concerns), a board, collar, and towels/foam wedges is the most stable immobilization, and allowing an individual to exit a car under his own volition with a collar in place may result in the least amount of movement of the cervical spine. Altogether, whereas any form of immobilization is superior to no immobilization, no available method is optimal, and there is no solid evidence to support the commonly accepted treatment standards of today.
In the recent AANS/CNS guidelines, Theodore and colleagues reviewed different methods of pre-hospital spinal immobilization and cautiously concluded that the most effective immobilization method seemed to be a combination of a rigid collar with supportive blocks on a rigid spine board with straps. To our knowledge, there are no studies showing a clinical benefit of using the double immobilization strategy with rigid collars and head blocks.
Studying the natural course of overlooked or missed fractures is another way of looking into the efficacy of cervical immobilization. For this surrogate marker of instability, it is important to keep the different perspectives of time in mind: The application and removal of a trauma collar usually spans a couple of hours, whereas the window between trauma and diagnosis for missed injuries can be from days to weeks. In one large, multi-center study, missed CSI presenting with a neurological deficit occurred in less than 1 of 500 spine injury cases and 1 of 4000 trauma cases, with an average delay in diagnosis of approximately 20 days. On one hand, there are studies where up to 8% of necks were not immobilized, seemingly without clinical consequences or progress to neurological deficits. Conversely, Gerrelts and colleagues identified the development of temporary neurological symptoms before treatment, but were unable to identify permanent complications in those with missed cervical fractures. Davis and colleagues and Platzer and colleagues reported that delayed diagnosis, in fact, resulted in permanent, severe deficits: Davis and colleagues reported 32,117 trauma patients, 740 cervical injuries, 34 injuries missed, 10 developed permanent deficits, whereas Platzer and colleagues reported 367 cervical injuries, 18 injuries missed, 8 developed neurological symptoms, and 2 permanent deficits.
Considerable force is required to fracture the spine, and subsequent low-energy movements are thus unlikely to cause secondary SCI. Plumb and Morris recently proposed that we should simply stop using collars in obtunded patients, because “it is likely that minor degrees of cervical spine movement are without consequence and more significant movement prevented by common sense.” Moreover, awake patients generally maintain a stable neck position with muscle contractions that protect the spinal cord. Additionally, and contrary to common belief, most spinal injuries are biomechanically stable in the acute phase, and unstable injuries that have not caused acute, irrevocable injuries are very rare. Conclusively, given that collars are ineffective in motion control, we are apt to conclude that the risks of inadequate immobilization may be substantially overemphasized.
It has been conservatively estimated that at least 50–100 patients have their neck immobilized for every patient that has a significant CSI. This ratio implies that cervical immobilization, usually involving a collar, must be safe and effective to provide a reasonable cost-benefit relationship. In an interesting article from Ghana, aimed at improving pre-hospital trauma care in developing countries, Tiska and colleagues recommended abandoning the concept of strict spinal immobilization in favor of a more pragmatic practice with simple spinal precautions. In this case, resource considerations have motivated a practice that is truly based on the lack of evidence supporting rigorous spinal immobilization.
In summary, the ATLS guidelines have significantly changed the way ambulance crews and hospital staffs think of and manage trauma patients, but there is little evidence to support a real benefit on patient outcome. For spinal immobilization in general, and collars in particular, there is insufficient evidence to support the currently recommended treatment routines with regard to mortality, neurological injury, or spinal stability.
Possible Adverse Effects of Cervical Collars
Collars may exacerbate CSIs, instead of protecting the individual from secondary progression. In this regard, it is vital to be aware that many collars are not fitted correctly, and it is therefore reasonable to assume that this can reduce the potential for motion control as well as increase the risk for neurological compromise. In a noteworthy study, though not without limitations, Hauswald and colleagues found an increased frequency of clinical deterioration and more overall neurological disability in patients with spinal injuries that were routinely fitted with a collar (Albuquerque, NM) than in patients that never received a prophylactic collar (Kuala Lumpur, Malaysia). Further, some of the strongest evidence of harm from collars comes from studies of patients with ankylosing spondylitis (Morbus Bechterew), where extension of the cervical spine during standard pre-hospital immobilization is very dangerous. This is not always evident at the trauma scene and not an uncommon disease; approximately 5% of all patients with cervical fractures had ankylosing spondylitis in Fredø and colleagues' study.
Associated head and spinal injuries are frequent; the ATLS guidelines state that 5% of patients with a TBI have an associated spinal injury, whereas 25% of patients with a spinal injury have at least a mild TBI. Avoiding or reducing an increased intracranial pressure (ICP) is fundamental in the management of TBI, and it is important to be aware that a collar may increase ICP by an average of 4.5 mm Hg through jugular venous compression. Interestingly, advanced life-support training of ambulance crews has been found to increase mortality among patients with a Glasgow Coma Scale (GCS) score <9 (typical cutoff for severe TBI), but whether this mortality increase is the result of complications associated with pre-hospital interventions, such as collar use, inadequate airway management, or transport delays to hospital is not established. Moreover, venous congestion by collars can also exacerbate global brain injuries, such as those observed after attempted suicide by hanging.
A key issue associated with collars in pre-hospital care is the increased difficulty it may entail for airway management. Mouth opening can be compromised and aspiration can more easily result from vomiting, especially in the supine position. Collars may also cause respiratory restriction, an effect that is more pronounced if spine boards are added. Notably, endotracheal intubation of CSI patients in the ED setting has not been shown to worsen neurological outcome, whereas reports on prehospital endotracheal intubation of TBI patients have shown better, unchanged, or impaired morbidity and/or mortality outcomes. Field intubation procedures are associated with more difficulty and complications than in-hospital procedures because of a wide range of factors. Further, prehospital intubation is not always available and the ability to perform this procedure safely varies among prehospital EMS personnel, with physicians having the highest success rates. Prioritizing advanced airway management and spinal immobilization may also delay release and rescue procedures as well as make the trauma examination more difficult, both at the scene, during transport, and at admittance. Delayed definitive care can be detrimental for patients with non-neurological critical injuries, and importantly, also lead to neurological progression, because spinal injuries are often neurologically unstable, but biomechanically stable in the acute phase.
In conclusion, it is essential to provide prompt, careful transport to definitive care. A number of practice options exist for airway management in CSI, but there are no outcome data that favor any particular practice. Nevertheless, after checking airways and breathing, unconscious patients with unsecured airways should not be transported in the supine position, but preferably in the lateral trauma position or HAINES (High Arm IN Endangered Spine) modified recovery position.
In our experience, collars can have a tendency to “paralyze” some health care personnel; they see it as a sign of uncertainty and possible serious injury and it may therefore compromise their ability to perform the necessary examinations or actions. Moreover, bystanders acting to help trauma victims at the accident scene may be “paralyzed” by the fact that the patient's neck is not secured and hence not act to secure, for example, the airways.
There are some major problems with pressure ulcers that result from collars, resulting also from strapping on spine boards. Additionally, discomfort, pain, and related stress responses are not an insignificant problem and can be a confounding factor in initial patient assessment and trauma management.
Patients that have received spinal immobilization are more likely to proceed to radiological examinations to “clear the neck.” This is concerning, in light of the accumulating evidence on the unfavorable radiation effects of computed tomography (CT) scanning, especially in children.
Pre-hospital spinal immobilization has been associated with higher morbidity and mortality in penetrating trauma patients and found unnecessary in patients with gunshot wounds to the head. Routine spinal immobilization in penetrating trauma is therefore not recommended.
Taken together, there is a large volume of studies disfavoring the routine use of collars. The accumulated information provided by these studies has, in our opinion, not been sufficiently appreciated and has had a marginal influence on the practice of pre-hospital spinal immobilization.
Specific Pediatric Concerns
The numerous concerns regarding collars in adult patients are mostly transferable to the pediatric population. Moreover, most of the foundation for pre-hospital treatment of children with CSIs is based on adult studies, and the evidence favoring current management strategies is therefore even weaker than in adults. Pediatric collars are adapted to the size and anatomy of children, whereas undesirable neck flexion on spine boards should be avoided by individual modifications. No studies have been identified that compare spinal stabilization with or without collars in children.
CSI in pediatric blunt trauma victims is rare and occurs in approximately 1–2% of patients, although more frequent with concomitant head injury. The anatomy and injury patterns observed in children older than 8 years resemble those of adults. Younger children have more high-level injuries, fewer fractures, more dislocations, and more SCIs because of their larger head/body ratio, greater ligament laxity, and more horizontal facet joints. Outcomes are often poorer in younger than in older children.
Despite presenting with comparable injury severity, children who undergo prehospital spinal immobilization have higher degrees of pain, are much more likely to undergo radiological examinations, and are more often admitted to hospital than those that are not immobilized. Several studies have raised concerns about childhood exposure to ionizing radiation (particularly CT) and an increased lifetime risk of cancer. Several low-risk prediction rules have been developed to avoid unnecessary prehospital spinal immobilization in children, but have proven difficult to validate, because these injuries are so uncommon.
Clearing the Cervical Spine in Conscious and Unconscious Patients
Cervical spine clearance in awake and alert patients is easier and better documented than in unconscious or obtunded patients. There are several clinical approaches available to substantiate whether or not awake patients have a significant CSI and thus are in need of radiological examinations and/or specific treatment. One of the best validated algorithms is the Canadian C-spine Rule (CCR). This was originally published in 2001 as a tool to decide whether or not patients require radiology in the hospital setting. In 2011, a revised edition was published for the pre-hospital setting, but now as a tool to decide whether patients require cervical spine immobilization or not.
High-quality studies have shown that physicians in the ED can safely use the CCR as well as the NEXUS (National Emergency X-Radiography Utilization Study) criteria to rule out CSI. Studies have also shown that the CCR is more sensitive and specific than the NEXUS criteria, and that using the CCR results in lower rates of radiological examinations. Further, the CCR can be used with similar accuracy and reliability by triage nurses in the ED and paramedics in the prehospital setting.
Education of pre-hospital personnel in clinical clearance of the cervical spine has a large potential for improving management, with an estimated 40% reduction in cervical spine immobilization (and subsequent radiological examinations).
Radiological investigations are often deemed unnecessary for conscious patients without symptoms, neurological deficits, or distracting injuries and that have a full range of motion upon functional examination. Evidence also suggests that this straightforward clearance approach can be simplified even further by ignoring distracting injuries, perhaps except for injuries in the upper chest region. Altogether, there is a wide range of algorithms based on different clinical criteria for clearance of the cervical spine in the prehospital setting.
Patients with reduced consciousness
Patients with reduced consciousness have a higher prevalence of CSIs, and cervical spine clearance in such patients is not as clear cut as in conscious patients. As a consequence, most patients are fitted with a rigid collar in combination with head blocks and strapped to a spine board during transport, and the collar remains on until they can be evaluated by imaging. However, based on the information presented so far, we can safely conclude that the presumed benefit of collars is highly questionable, and that there is a large body of evidence on the risks and complications of this practice. Particularly concerning for this patient category are the reports of increased ICP when collars are applied as well as data suggesting increased mortality rates for patients with a GCS score <9 that have been managed by ambulance crews skilled in advanced life support. Expeditious transport to definitive care is vital for unconscious CSI patients, and this should take priority over rigorous immobilization measures. Moreover, and as previously discussed, unconscious patients with unsecured airways should not be transported in the supine position.
Pre-hospital application of collars is well implemented, despite the lack of evidence to support this practice. Thus, it has been advocated that a practice change can only be initiated within the confines of a clinical trial, providing high-quality data on the benefits and risks of cervical immobilization. This will most likely require a large, multi-center RCT, which is a daunting task in itself, but even more so with certain challenges of prehospital research (e.g., ethical considerations, patient informed consent, randomization procedures, patient follow-up, time-pressured environment, and protocolized mindsets). Alternatively, one may explore the possibility of developing new clinical treatment guidelines through an expert consensus process involving both pre-hospital and hospital environments.
Finally, it seems reasonable to strive for a more individualized prehospital approach to obtunded patients at risk of having a potential CSI. One way of doing this could be to incorporate knowledge from extensive epidemiological surveillance studies, such as a recent European multi-center study including more than 250,000 patients, which, by multivariate analysis, tried to identify various risk factors of CSI in trauma patients. Efforts should also be concentrated on developing new devices that are more easy, safe, and effective to use.
The existing evidence for using collars is weak, and our practice is mainly a result of the historical influence of poor evidence. More significant and concerning, there is a well of less-appreciated documentation of harmful effects from collars. A practice change seems warranted based on a critical evaluation of the pros and cons of pre-hospital collar use in trauma patients.
With this perspective, we propose a safe, effective immobilization strategy that will not require any new equipment and should be easy to implement; the main difference from current protocols is the omission of routine collar application. Few patients are in need of spinal immobilization, and clearance protocols should be optimized to identify these high-risk patients. These patients should not be fitted with a collar, but immobilized on spine boards with head blocks and straps. Temporary use of a rigid collar is an option during extrication procedures from, for example, cars. Unconscious, non-intubated trauma patients should be transported in a modified lateral recovery position that maintains near neutral spine alignment and airway patency. Finally, pre-hospital management should, by no means, delay transportation of critically injured patients to definitive care.
Future efforts should also aim to discontinue the use of rigid spine boards in favor of vacuum mattresses or other softer boards that are more comfortable and adaptable to the individual variations in body composition.
THE CURSE OF THE CERVICAL COLLAR
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 rouge 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. Immobilization 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 stabilize the area, even in the unconscious patient. And carefully moving the unconscious patient or carefully 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 immobilized – 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 stabilize the neck much. Even a perfectly allied 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 immobilize 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 unconscious 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 stabilization 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, the UK Faculty of Pre-hospital Care has recently released new guidelines for managing spinal injuries – and the counter-revolution has just started.
Why EMS Should Limit the Use of Rigid Cervical Collars
Making the case for soft collars & alternative methods of spinal stabilization.
Journal of Emergency Medical Services. Mon, Jan 26, 2015
By Bryan Bledsoe, DO, FACEP, FAAEM, EM
Over the last few years we've seen significant changes in the pre-hospital treatment of patients with potential spinal injuries. We've quickly gone from using rather extensive spinal mobilization techniques to doing virtually nothing.
Few of the recent advancements in EMS have been this significant. As a result, these changes have caused considerable angst among both pre-hospital providers and hospital-based personnel. However, it's been said that the first step toward change is awareness. The second step is acceptance. Winston Churchill once said, "To improve is to change; to be perfect is to change often." Change can be good.
Rarely does a day go by when we don't learn of an EMS system that has abandoned backboards and the older archaic practices of pre-hospital spinal immobilization. This trend began initially in North Carolina and later in California. Now, most of the progressive EMS systems have discarded or changed their spinal immobilization practices. They've replaced these with various strategies that minimize backboard use.
The impetus for these changes was various scientific studies that showed spinal immobilization, as previously practiced, was ineffective.1 Some studies also demonstrated that spinal immobilization practices were possibly causing harm.
This was the principal reason this issue came to the forefront. There were significant discussions among various interested factions regarding these changes. However, there was enough of a groundswell support to effect change.
Now, spinal precautions are much simpler and much more comfortable for the patient. There's little argument that the backboard as an immobilization device is ineffective.But, one has to wonder about cervical collars (C-collars) as well. Many EMS systems have elected to use rigid collars without backboards. Is this the best practice? Is this practice effective?
Interestingly, one of the first protocols that significantly changed spinal immobilization practices came out of several EMS agencies in Northern California. In a rather sweeping protocol change, they elected to forgo rigid C-collars and use soft collars.
Those of us who've been in EMS for a long time remember using soft collars for potential spinal injuries before the rigid collars were available. But to understand why we initially switched to rigid C-collars, it's important to review some concepts that led to the older spinal immobilization practices. They were based on the following assumptions:
- Injured patients may have an unstable cervical spine (C-spine) injury.
- Additional movement of the C-spine might result in additional damage to the spinal cord beyond that
caused by the initial trauma.
- The application of a rigid or semi-rigid C-collar may prevent potentially harmful movements of the C-spine.
- Spinal immobilization is a relatively harmless procedure and can therefore be applied to a large
number of patients with a relatively low risk of injury. It's often used as a precaution.
Unstable C-Spine Injury?
Unstable C-spine injuries do occur, yet they're relatively rare. In the United States it's estimated that there are approximately 12,000 new cases of spinal injury annually. Most of these result from motor vehicle collisions.
Over the last several years the number of patients with quadriplegia (cervical injuries) has decreased.2 In patients who are alert and stable, the incidence of clinically significant C-spine injuries is exceedingly low.3 The National Emergency X-Radiography Utilization Study (NEXUS) criteria and Canadian C-spine rules were developed to help physicians determine which patients with possible C-spine injuries from blunt trauma require diagnostic imaging (e.g., CT, X-ray, MRI).4,5
If the patient doesn't require imaging, then they don't require immobilization. This was the basis for the development of the selective spinal immobilization protocols used in EMS.6 The term for this was later changed to spinal motion restriction (SMR) as it was recognized that the spine couldn't be truly immobilized. These protocols were found to be accurate and effective. The initiation of a statewide selective spinal immobilization protocol in Maine reduced spinal immobilization in that state by over 50%. The protocol only missed one patient with an unstable spinal injury out of 32,000 pre-hospital trauma patient encounters.8 The use of SMR protocols has been widely used in EMS for years and has safely reduced the use of spinal immobilization. However, many providers have been reluctant to use it.9
Attention was then turned to patients with penetrating trauma. It was a common practice to immobilize patients with penetrating injuries. However, it was found that spinal injuries from penetrating trauma were quite rare. Furthermore, it was found that immobilization of patients with penetrating injuries actually worsened outcomes.11,12 When present, these injuries are readily apparent on physical examination and generally never get better.13
This resulted in the development of guidelines and protocols to limit spinal immobilization of patients with penetrating trauma by the American College of Surgeons (ACS) and Pre-hospital Trauma Life Support (PHTLS).
Worsening the Damage?
It was always thought and taught that additional movement of the spine in a patient with a spinal injury would actually worsen the condition or result in a secondary injury. There are really no data to support this. There are a couple of reasons for this. First, the initial mechanism of injury causing the spinal injury is usually significant, and simple movements during patient care are unlikely to be as severe.
Also, the natural responses of the body to a serious injury actually provide somewhat of a de facto splint. With C-spine injuries, the muscles of the neck contract and that, along with pain, limits additional severe motion.
Preventing Harmful Movement?
First, as detailed above, there's no evidence that additional simple movements of the C-spine cause additional damage. Even if that's assumed to be true, to stop the C-spine from moving would require the neck be completely immobilized in all axes of movement. This is difficult because the range of motion of the C-spine is rather extensive. (See Figure 1 above.) Placing the patient in a simple C-collar isn't going to stop all axes of movement. Also, one must remember that the neck is attached to the body. Even if the C-spine were firmly immobilized, movement of the body below the neck would also cause movement of the neck.
In other words, it's impossible to immobilize the C-spine without immobilizing the entire patient. There's absolutely no evidence the C-spine can be immobilized to any significant degree. Even the post-operative halo frames used by neurosurgeons still allow 4 degrees of motion when properly placed.17
A 1998 study found that the rigid collars commonly used in hospitals (e.g., Aspen collar) reduce spinal motion somewhat, but don't immobilize the spine. This led the authors to remark, "Cervical spinal immobilization is a myth."18 Common pre-hospital
C-collars allow even more movement than the Aspen collar.19,20
It's repeatedly been argued that spinal immobilization is a relatively harmless procedure and the perceived benefits certainly outweigh any perceived risks. It was often said, "When in doubt, immobilize the spine." Much of this came from the 1984 U.S. Department of Transportation Emergency Medical Technician—Ambulance: National Standard Curriculum.
For reasons that remain enigmatic to this day, the decision was made to "dumb down" the EMT curriculum so more people could obtain the training. It was much easier to teach EMTs to apply spinal immobilization rather than teach them to determine which patients might need spinal immobilization and which may not.
Soon, the indications for prehospital spinal immobilization became simply the presence of a patient. This paralysis of intellect resulted in the current immobilization craze of all patients suffering from seizures to simple falls to minimal-energy motor vehicle collisions (that soon become multiple casualty incidents because the five occupants of the vehicle have a little neck and back pain and therefore must be immobilized).
Initially, that argument to immobilize "just in case" may have had some merit. Now, significant studies have shown that C-spine immobilization, and specifically application of rigid C-collars, is a potentially dangerous practice.21 The reasons include:
C-collars interfere with airway management: There are a considerable number of studies that have shown C-spine immobilization practices can interfere with airway management. Even a properly applied rigid C-collar restricts mouth opening by 25% or more. Interestingly, there has never been a documented case where endotracheal intubation caused or worsened a C-spine injury.23 Yet, how many trauma patients have died because of inability to obtain an airway because of concerns about the C-spine?
C-collars increase intracranial pressure: It's been clearly demonstrated that even proper application of a rigid C-collar can increase intracranial pressure. This is particularly problematic because many patients with spinal injuries also have head injuries where an increase in intracranial pressure can be devastating.
The principle behind this is simple. C-collars are often tight enough on the neck to restrict venous drainage of the head through the jugular veins. They're not tight enough to restrict arterial inflow through the carotid and the vertebral arteries.
Thus, arterial blood flowing into the cranial vault continues unimpeded while venous outflow is restricted. Since the cranial vault is a closed space, this causes increased intracranial pressure. The amount of the increase varies but the phenomenon has been well documented.24–26
C-collars increase spinal motion in high C-spine injuries: Injuries of the high C-spine are among the most catastrophic spinal injuries that occur and involve the first (C1) through the fourth (C4) cervical vertebra as well as the joint between the skull and the first cervical vertebra (atlantooccipital joint). Application of a rigid C-collar causes the separation of C1 from C2, thus stretching the high spinal cord.
This was first reported in a patient undergoing diagnostic imaging and was later studied using embalmed cadavers where rigid C-collar application resulted in a 7.3 mm ± 4.0 mm of separation between C1 and C2.27 In high C-spine injuries, rigid collars can actually worsen the patient's condition.
C-collars cause pressure sores: Although not commonly seen in the pre-hospital setting, rigid C-collars cause increased tissue pressure and subsequent pressure sores. This can cause pain for the patient and increases the chances of secondary infection. C-collars are uncomfortable: It's no secret that rigid C-collars are uncomfortable. Because of this, a major goal in the ED and trauma center is to get the patient off of a backboard and out of a C-collar as fast as possible. C-collars can cause increased diagnostic imaging: EMS and hospital-based care are becoming more integrated. It's essential pre-hospital personnel consider what occurs after the patient has been delivered to the hospital. This is especially true for patients with potential spinal injuries.
The application of a rigid C-collar causes discomfort. Being placed on a hard backboard also causes discomfort. Even over a short period of time, patients in spinal immobilization will develop pain and tenderness in their C-spine.
When the patient is subsequently examined in the ED or trauma center, the treating physician will look for mid line tenderness, among other things, to determine whether diagnostic imaging is necessary.
Both the NEXUS criteria and Canadian C-spine rules are partially based upon the presence or absence of mid line C-spine tenderness.
Oftentimes, patients who didn't have mid line point tenderness when placed in a C-collar and/or on a backboard are found to have tenderness after being on the backboard for a short time.
The presence of tenderness can mandate diagnostic imaging. In a study of pediatric patients, it was found that children who were immobilized in the pre-hospital setting were more likely to be imaged, more likely to be admitted to the hospital, more likely to be admitted to the ICU, and were found to have more pain than their counterparts who weren't immobilized. C-collars can foster a false sense of security: Once a patient has been placed in spinal mobilization, healthcare personnel often assume they're safe and can be easily moved. This was based on the idea that their spine was securely immobilized. Now, we know this isn't the case.
2015 & Beyond
Changes in pre-hospital spinal immobilization protocols are rapidly occurring across the country. Because these were such stark changes when compared to prior practices, many EMS systems have decided to make these changes in measured steps. Some simply tried to reduce the use of backboards. Others eliminated sandbags, head supports and tape.
Some elected only to use rigid C-collars and place the patient onto a soft bed as soon as possible. Some have now replaced the rigid C-collars with a soft foam C-collar as the only device for spinal immobilization. It's now known that current devices don't allow for true immobilization of the spine. It's also known that rigid C-collars cause the numerous problems as detailed in this article. The soft C-collar doesn't immobilize the C-spine, but it serves as a reminder to the patient to limit movement of their neck.
This is just as effective as the limitations in movement afforded by rigid cervical collars—but is much more comfortable for the patient. This was the concept when soft C-collars were used in EMS 30 to 40 years ago and also makes sense today.
Although not an EMS study, a 2010 research paper compared rigid C-collars to soft foam C-collars during flexion, extension, lateral bending and rotation of the head and neck. Although the subjects exhibited a more limited range of motion of the C-spine when immobilized in a rigid collar than when placed in a soft collar, the motion recorded during the various functional tasks wasn't significantly different regardless of which cervical device was applied.34
It's taken over 20 years to develop the necessary body of scientific evidence to change our practices of spinal immobilization. Fears of worsening a spinal injury, fears of missing a spinal injury and fears of litigation have long driven this process instead of scientific evidence.
In the course of this we've made our patients uncomfortable, sometimes hurt them, and made their healthcare more complicated and more expensive. This is one of the best customer satisfaction practices that EMS can adopt. It's important to point out that we shouldn't abandon our various tools for moving patients. There's a limited role for backboards in extrication. Scoop-type stretchers and basket stretchers are excellent devices for moving patients, especially over uneven or rough terrain.
The vacuum mattress is also an excellent device for moving patients and actually provides probably the best stabilization of the spine of any device out there.
We don't want to throw the baby out with the bathwater; we just want to provide the best possible evidence-based care for our patients. Overall, our patient care will improve and our patients will remain more comfortable.