To Immobilize or Not Immobilize: That Is the Question
You and your partner arrive at the scene of a motor vehicle accident and find a lone vehicle with moderate front-end damage crashed into a tree. The air bag has deployed and there is no one in the car. You find the sole occupant standing on the sidewalk talking with a bystander. Your partner secures the man's neck with manual stabilization.
During your assessment, the patient complains of left knee pain, but he is bearing weight on it with a symmetrical gait. He denies having had anything to drink. You palpate his cervical spine, and he denies any pain or tenderness. He has symmetrical grip strength and is able to feel his fingers when questioned. You ask him to rotate his neck, and he is able to do so without pain. The patient agrees to go to the hospital and is transported sitting upright on the gurney without spinal precautions.
New Criteria Developed
Immobilizing a patient used to be such a simple decision. No matter how trivial the mechanism of injury, you strapped the patient down on the backboard and transported him to the emergency department, where he lay flat on his back--unable to move--until an x-ray technician took a picture of his neck. Since a lot of patients have some sort of blunt trauma mechanism, that means we used a lot of backboards and shot a lot of x-rays.
A few years ago, emergency departments in the United States and Canada began looking for ways to reduce the resources used for patients with little chance of actual injury.1 Reduced imaging served to decrease unnecessary costs and patient exposure to radiation. A set of criteria was created to measure the potential for cervical spine injury in patients with blunt force trauma.
The National Emergency X-Radiology Utilization Study (NEXUS) group's low-risk criteria were developed as the tool used to determine the need for patients to receive x-rays.2 This tool was specifically proposed to reduce the use of x-ray to rule out cervical spine injury and was not originally intended for prehospital providers to make decisions about immobilization in the field. As a tool to decrease unnecessary x-rays, it was shown to be an effective device.3
There are potential risks associated with prolonged spinal immobilization, particularly regarding pain and discomfort for the patient.4 With a similar aim to decrease unnecessary use of resources and patient discomfort, some EMS systems in the United States and elsewhere have developed protocols allowing prehospital providers discretion in applying spinal precautions to patients with blunt trauma mechanisms of injury. Many of these algorithms use the NEXUS low-risk criteria as their basis, and some have added elements of another clinical c-spine clearance process--the Canadian C-Spine Rule.5
There has been some trepidation about providing these protocols to nonphysician caregivers outside the hospital; however, evidence shows that prehospital personnel can adequately determine which patients require cervical spine immobilization.6 The majority of emergency physicians believe adequately trained prehospital personnel should be able to clinically determine the need for spinal precautions.7 Despite that confidence, comparing the ability of prehospital personnel to emergency department physicians has shown mixed success.8,9 The best correlation between physicians and paramedics was accomplished using simulated patients in a standard setting.10 Indeed, a similar study using only simulated patients revealed that EMT-Basics and lay college students could adequately choose which patients to immobilize.11 These types of studies may not accurately reflect the tendencies of field providers when determining the need for immobilization. The reality is that prehospital personnel perform in a dynamic environment distinctly different from that of the emergency department.
In a perfect world, the personal effort riding on the prehospital provider's decision (and the effort of the rest of the prehospital team) would have no bearing on the provider's decision, but the reality may be more pragmatic. Regardless of a physician's decision about the patient's need for x-rays, he will not have to actually shoot the films. If, on the other hand, a paramedic decides a 300-lb. patient needs to be immobilized, he will have to slide that patient onto the backboard and lift it into the ambulance. When comparing real-world field clearance to that of simulated patients, prehospital personnel almost always choose to immobilize fewer patients than their physician counterparts would have.8,9
Ruling Out Immobilization
While almost every EMS system using some sort of discretion process has developed its own decision tool, taking a look at the criteria developed by the NEXUS group will help prehospital providers to better apply their local method. The NEXUS tool uses five criteria to determine if the patient needs x-rays to rule out cervical spine injury:2
- normal level of alertness
- no evidence of intoxication
- absence of painful distracting injury
- absence of midline cervical tenderness
- absence of focal neurologic deficit.
Normal level of alertness
Assessing the cervical spine is entirely subjective, and the patient must be a full participant in the evaluation process. If the patient is unable to focus on his own cervical spine, the provider will have an inaccurate evaluation. Caregivers must take an all-or-nothing approach to this assessment criterion; patients presenting with any decrease in responsiveness should be fully immobilized.
It is hard to define decreased level of alertness. Prehospital providers can often restrict assessment of mental status to a patient's ability to identify name, location and the day or time. In clearing the cervical spine, consider any Glasgow Coma score of 14 or less, difficulty with recall, or delayed response to verbal stimuli as decreased alertness.2 It goes without saying that patients requiring pain to stimulate a response would have a decreased level of alertness.
No evidence of intoxication
Sedation, whether by alcohol or another substance, impairs the patient's ability to feel pain or tenderness and negates any assessment. There is some redundancy here, in that intoxicated patients will often respond more slowly to stimuli. Note that the standard is simply evidence of intoxication. It is impossible in the field to determine ingested levels of intoxicants; therefore, prehospital personnel must be careful and choose immobilization if there is any question of impairment.
Absence of painful distracting injury
The theme of the first three criteria is concentration. The last determinant of a patient's ability to concentrate on his cervical spine is to establish that no other injuries exist that will distract the patient. Defining distracting injury is probably the most difficult of all the criteria. Examples of common distractions may include fractures in any location and significant injury to the upper torso.12,13
Medical complaints may also complicate assessment of the cervical spine. While the unlikely coincidence of significant medical complaint and major mechanism of injury presenting simultaneously is remote, it is undoubtedly possible. It is important to weigh medical complaints with the same consideration given to distracting injury. Ischemic cardiac chest pain or severe shortness of breath will distract patients with the same ferocity as significant injury.
Keep in mind that applying this decision tool takes time, as does spinal immobilization. Patients presenting with non-spinal trauma significant enough to make the caregiver concerned should be immobilized as a matter of course rather than delaying transport. Also, patients with significant multi-trauma presentation will undoubtedly have distracting injury. A patient with non-life-threatening, isolated injury may not need immobilization if the injury does not interfere with c-spine assessment. If, however, the patient repeatedly tries to draw your attention to another area of more significant pain each time his neck is touched, consider that evidence of a distracting injury and immobilize him.
In the interest of a subjective assessment that requires patient participation, clear communication is essential. Patients with developmental disabilities, language barriers, hearing disabilities or dysphasia cannot adequately communicate with caregivers, and older or young patients may have communication difficulties. Elderly patients may also have decreased pain perception. Spinal precautions should be taken with any patient having difficulty adequately communicating to the caregiver. Indeed, there is evidence that age can affect the efficacy of selective immobilization and clinical clearance.14,15
Another area not addressed by the NEXUS low-risk criteria is environmental distraction. Patients cleared by clinical evaluation in the emergency room are cleared in an indoor environment. By contrast, patients evaluated in the field are surrounded by sound and commotion that may overwhelm them. The purpose of an immobilization decision tool is to evaluate a patient who is able to concentrate and participate in the process. If the patient is unable to focus on the assessment and nothing can be done to reduce distractions from the environment, he should be fully immobilized.
Absence of midline cervical tenderness
Once you determine that the patient is capable of giving his undivided attention to the c-spine, palpate the midline cervical spine from the base of the skull to the thoracic vertebrae. Any midline tenderness is assumed to be a cervical spine injury and warrants immobilization. There is some debate about the significance of lateral tenderness, which may create a distracting injury that necessitates immobilization. Lateral tenderness may also impede further evaluation of the cervical spine and therefore necessitates spinal precautions.
Absence of focal neurologic deficit
There is a basic rule in spinal immobilization that has been around since Johnny and Roy: If there is numbness or paralysis after blunt trauma, strap 'em down. There should be symmetry in the patient's grip strength and feeling in all extremities. This is one criterion that could be easily overlooked in ambulatory patients.
The Canadian C-Spine Rule, a more recent clinical clearance device, evaluates patients with a three-step process. Even though this rule requires clinicians to answer only three questions, it is a complicated protocol to apply in the prehospital setting. The evaluation is remarkably similar to the NEXUS low-risk criteria; however, the Canadian C-Spine Rule measures two additional items.16 Based on this, many EMS systems include two additional criteria in their decision trees:
- ability to rotate the neck (or full range of motion)
- absence of a significant mechanism of injury.
Ability to rotate the neck
Certain clinically significant injuries may be detectable through pain precipitated by moving the head. Some systems use a full range of motion assessment that not only has the patient rotate his neck 45 degrees to the left and right, but also flex and extend it. Regardless of which type, in systems that use a range-of-motion standard, patients with lateral neck pain may not be able to rotate their necks and will therefore need to be immobilized.
Absence of a significant mechanism of injury
The Canadian C-Spine Rule, as well as several local protocols, considers the mechanism of injury to determine the patient's potential for injury. Much like distracting injury, significant mechanism of injury is difficult to define. Many systems have a list of criteria that require a patient to be immobilized. Nevertheless, it is difficult to identify all possible major mechanisms of injury, and prehospital providers must consider the goal of spinal assessment as they apply the decision tool.
For EMS systems that do not measure mechanism of injury, consideration is at the discretion of the prehospital provider's individual comfort level. However, there is evidence that mechanism has no bearing on the ability of these decision tools to exclude cervical spine injury.17
In the emergency department, the benefit of clinical clearance--besides cost savings--is largely related to the patient spending less time strapped to a backboard or waiting in an emergency bed and receiving less exposure to ionizing radiation. The consequence of a missed cervical spine fracture, on the other hand, can mean permanent loss of function or feeling. Potential litigation plays a major role in clinical clearance, especially for physicians, and will continue to do so in the foreseeable future.
Despite its growing presence, selective spinal immobilization in the prehospital setting is still a delicate issue. Advocates for both sides debate whether prehospital providers should be able to clear patients or immobilize every blunt force trauma patient. There is little empirical data to suggest significant negative patient impact from spinal immobilization on a long backboard. Some data suggest that spinal immobilization in the field has no benefit to patients with cervical spine injury.18
Prehospital providers have been largely insulated from the effects of litigation in most areas of clinical practice, with the exception of omission of care issues like refusal of service. In deciding to omit spinal immobilization in a patient population determined to have only a slight chance of spinal injury, there exists a potential for litigation that prehospital providers have not yet experienced.
Reducing the use of spinal immobilization for patients deemed at low risk for injury may be a good idea. There is anecdotal evidence that some patients, especially the elderly, are negatively affected by prolonged immobilization.19 But without empirical evidence to substantiate that assertion, withholding cervical spine immobilization will continue to be a liability for responders outside the hospital.
For those practicing selective immobilization, the strongest protection from liability is to avoid aggravating or causing injury by withholding c-spine immobilization from a patient who needs it. That means applying c-spine decision tools as objectively and carefully as possible. Prehospital providers in areas that use those tools should be trained to adequately assess the cervical spine and receive regular continuing education to maintain adequate performance. Applied correctly, selective spinal immobilization can be a great tool for decreasing patient discomfort, encouraging reluctant patients to seek medical care and reducing patient-provider conflicts. Any system that chooses to selectively apply cervical spine immobilization to trauma patients must regularly review cases in which spinal immobilization is withheld to determine effectiveness of, and ensure adherence to, decision criteria. Patients deserve the best care we can give them, with or without immobilization. References
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2. Panacek EA, Mower WR, Holmes JF, et al. NEXUS Group. Test performance of the individual NEXUS low-risk clinical screening criteria for cervical spine injury. Ann Emerg Med 38(1):22-25, Jul 2001.
3. Hoffman JR, Mower WR, Wolfson AB, et al. National Emergency X-Radiography Utilization Study Group. Validity of a set of clinical criteria to rule out injury to the cervical spine in patients with blunt trauma. N Engl J Med 343(2):94-99, Jul 13, 2000.
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6. 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 46(2):123-131, Aug 2005.
7. Cone DC, Wydro GC, Mininger CM. Current practice in clinical cervical spinal clearance: Implication for EMS. Prehosp Emerg Care 3(1):42-46, Jan-Mar 1999.
8. Meldon SW, Brant TA, Cydulka RK, et al. Out-of-hospital cervical spine clearance: Agreement between emergency medical technicians and emergency physicians. J Trauma 45(6):1058-1061, Dec 1998.
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10. Sahni R, Menegazzi JJ, Mosesso VN Jr. Paramedic evaluation of clinical indicators of cervical spinal injury. Prehosp Emerg Care 1(1):16-18, Jan-Mar 1997.
11. Dunn TM, Dalton A, Dorfman T, Dunn WW. Are emergency medical technician-basics able to use a selective immobilization of the cervical spine protocol? A preliminary report. Prehosp Emerg Care 8(2):207-211, Apr-Jun 2004.
12. Heffernan DS, Schermer CR, Lu SW. What defines a distracting injury in cervical spine assessment? J Trauma 59(6):1396-1399, Dec 2005.
13. Chang CH, Holmes JF, Mower WR, Panacek EA. Distracting injuries in patients with vertebral injuries. J Emerg Med 28(2):147-152, 2005.
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 37(6):609-615, 2001.
15. Barry TB, McNamara RM. Clinical decision rules and cervical spine injury in an elderly patient: A word of caution. J Emerg Med 29(4):433-436, Nov 2005.
16. Stiell IG, Clement CM, McKnight RD, et al. The Canadian c-spine rule versus the NEXUS low-risk criteria in patients with trauma. N Engl J Med 349(26):2510-2518, Dec 25, 2003.
17. Domeier RM, Evans RW, Swor RA, et al. The reliability of prehospital clinical evaluation for potential spinal injury is not affected by the mechanism of injury. Prehosp Emerg Care 3(4):332-337, Oct-Dec 1999.
18. Hauswald M, Ong G, Tandberg D, Omar Z. Out-of-hospital spinal immobilization: Its effect on neurologic injury. Acad Emerg Med 5(3):214-219, 1998.
19. Vickery D. The use of the spinal board after the prehospital phase of trauma management. Emerg Med J 18(1):51-54, 2001.
Rod Brouhard is a paramedic for American Medical Response in Modesto, CA, and former director of the EMS program at Modesto Junior College.