This article is for education purposes
This is not an approved practice in our region 

You’re called to a two vehicle 10-50 in which a trucked T-boned a car. First responders are attending to the driver of the truck and are stabilizing his cervical spine. He states he was restrained and complains only of mild pain in his left arm. He is awake and oriented and agrees to be transported. What do you do now? If you were to follow the DOT curriculum to the letter, you would immediately apply a cervical collar and possibly a KED board and extricate him from the vehicle onto a long backboard for transport. However, is that the most appropriate treatment? Are there circumstances when spinal immobilization can be waived following trauma? Do you do it because of how you were taught or is it simply protocol to immobilize everyone?

Until recently the general practice of EMS has been to place all trauma victims into cervical collars and onto longboards despite their presentation and complaint. But now, research and review of our practice has shown that there are safe and effective means to determine who does and does not require immobilization. In this article we will review the anatomy and physiology of the spine and spinal injuries and discuss the implications of recent research which has promoted the development of new immobilization protocols. We will examine these protocols and determine how we might implement them in our service.

Before we go any further, it should be noted that I have not titled this topic cervical spine clearance but instead selective spinal immobilization. As we will discover, the process of determining whether or not someone has a spinal cord injury requires diagnostic tools unavailable to the pre-hospital provider. These tools are utilized on the patient felt to be at a higher risk for injury and would by default arrive immobilized. Instead, we are talking about the critical thinking process which must be undertaken to determine who does and does not require spinal immobilization during transport. This we will term "selective immobilization."

Anatomy of the Spine
To better understand the implications of this discussion, it important that we first review the anatomy of the spine and the types of injuries that can occur. The spinal cord exits the base of the skull through an opening called the Foramen Magnum and extends down the length of the spinal column running through the spinal canal formed by the vertebra. It terminates in the mid lumbar region with a tail of nerve fibers which extend downward and exit the sacrum. While we are primarily concerned with the spinal cord itself, it is injury to the bony skeleton of the spinal column and/or the associated soft tissue structures which results in the potential for spinal injury. The bony skeleton consists of seven cervical, twelve thoracic, and five lumbar vertebrae which can move when the body is in motion. The five sacral and four coccygeal bones are fused and are part of the pelvis. The movable vertebrae are supported by ligaments and muscles to help maintain their alignment. These disks are separated by a cushion-like structure called the intervertebral disk.

Various types of injuries can occur to the spinal column from a host of different mechanisms and a full discussion of all of them is beyond the scope of this article. But suffice it to say, it is disruption of the integrity of the bony spinal column which results in the injury to the spinal cord. This disruption occurs from either tearing of the ligamentous support structures or the compression or fracture of the bony elements. In fact, the ligamentous support is the most crucial as their disruption determines how "unstable" the likelihood of further injury occurring to the spine after the initial injury. The end result is either the compression of the cord by bone fragments or stretching of the cord from excessive forces.

When energy is applied to the cervical spinal column as a result of trauma, it can come in multiple directions. The cervical spine is best protected from compression and to some extent extension of the neck but poorly from flexion, distraction, (hanging) and rotation. While it seems we are most often concerned with the cervical spine, it is important to realize that the thoracic and lumbar spine can be injured to the same degree and by the same mechanisms.

The next issue we must consider is that of primary and secondary injury. The primary spinal cord injury occurs at the time of trauma with direct injury to the spinal cord. This presents immediately with neurological deficits. Secondary injury occurs following the traumatic event and results from swelling of the cord, swelling of the surrounding soft tissues, protrusion or herniation of the intervertebral disk or the formation of a hematoma next to the cord. These injuries present slowly and progressively and may not be noticeable for hours, days and even months after the injury. Spinal immobilization is theoretically based on the premise that further injury to the injured spine will be reduced by keeping the spinal column in the natural and anatomic position.

How big is the problem?
To determine just how common these injuries are and how to discover them a multi-center study has been underway since 1998. The National Emergency X-Radiography Utilization Study (NEXUS) is a large, multi-center, nationally funded prospective study designed to define just how well the presence of certain physical findings can be used to determine who does and does not have a significant spinal injury. In their initial report of 34,069 blunt trauma patients, they found that 2.4% sustained a cervical spinal injury. The second cervical vertebra (axis) was the most common level of injury representing 24% of the injuries. The combined injuries to the two lowest cervical vertebrae (C6 and C7) represented 39% of the injuries. A fracture of the vertebral body was the most frequent site of fracture. More importantly, nearly one third of the injuries were considered to be clinically insignificant.

Thoracolumbar spine injures occur in about 6% of blunt trauma or about twice as often as cervical spine injuries. They are fairly evenly distributed between the 12th thoracic and the 3rd lumbar vertebrae accounting for 52% of the injuries. This is easy to understand since this region is the most flexible of the lower spine.

The NEXUS and other studies examined the presence of abnormal x-ray studies which would identify the patients with primary injuries. But what about the patient with a secondary injury who’s x-rays are normal? This condition is called spinal cord injury without radiographic abnormality (SCIWORA) and is determined through the use of magnetic resonance imaging (MRI). NEXUS informs us that this occurred in only 0.08% of their patients. That’s only eight out of every 10,000 trauma patients!

More from NEXUS
The primary focus of the NEXUS research was to determine whether or not the presence and absence of certain physical findings could be used to decide which blunt trauma patients can safely be excluded from having x-rays taken to "clear" their cervical spine. These criteria were defined as 1) midline cervical tenderness, 2) altered level of consciousness, 3) evidence of intoxication, 4) neurologic abnormality, and 5) presence of painful distracting injury. Of the 34,069 patients, 818 patients were found to have a cervical spine injury (CSI). Utilizing these criteria they found that all but 8 of those with CSI and all but two of the 578 with significant CSI were identified by using these criteria. More importantly, 29% of those with CSI and 30% of those with significant CSI met only one of the five criteria. Therefore, neglecting to utilize ALL five criteria during the examination significantly reduced the ability of this process to identify the patient with CSI. To put it another way, by using the criteria, 99.8% of the patients with cervical spine injuries were identified. That value rivals the predictive value of a pregnancy test, an EKG, and most of the other tools we routinely use to screen patients. Moreover, using these criteria appropriately would reduce the unnecessary use of x-rays by more than 30% resulting in significant cost savings to the patient and healthcare in general.

Once this study was completed, the natural question was asked, "Can these criteria be safely used in the pre-hospital arena to selectively determine which patients warrant spinal immobilization?" The reason for this question is that it has already been determined that patients presenting to the hospital in spinal immobilization are significantly more likely to get x-rays merely because they have been immobilized regardless of the presence or absence of these criteria and because the mere process of placing a blunt trauma victim in immobilization increases their complaints of pain and therefore increases the likelihood that they would receive x-ray tests. The preliminary results are in and the answer is yes, if the criteria are appropriately utilized.

Applying these criteria in the street
The primary reservation of applying the NEXUS criteria by EMS is the concern that EMTs may not be as proficient as physicians in assessing the presence of the five criteria. Current studies are underway to determine whether or not this is in fact true and therefore, organizations such as the American College of Surgeons has suggested that they be modified to reflect the impact of mechanism of injury and other factors in their pre-hospital application. For example, a deeper examination of the data indicates that CSI occurred twice as often in the elderly and in particular that 20% of their fractures were of the second cervical vertebrae compared to only 5% or the non-geriatric group. Further, the prevalence of CSI in children is not well documented and the ability to apply the criteria to both age extremes appears to be difficult. Also, we know that certain mechanisms of injury just seem too great not to put the patient in spinal immobilization regardless of how good they look. This is not a bad recommendation and gives you more leeway in applying the criteria in the field. So let’s look at the criteria and determine how you would apply them. We will take them in reverse order as their presence would negate the need to perform any of the others.

A painful distracting injury is any injury which is causing the patient so much pain that they don’t recognize that their neck hurts or that they have numbness or weakness. The most common distracting injuries are obvious fractures and severe soft tissue injuries such as large lacerations, crush injuries, burns and contusions. If you are unable to keep the patient from concentrating on these injuries, you will be unable to proceed and should immobilize the patient.

The most common neurological abnormality is weakness. This weakness can be bilateral or only one sided. Numbness is rare and is more commonly perceived as a "funny" feeling in the extremities such as tingling or burning in the extremities. By asking the patient to grip your fingers with both hands and wiggle their feet you should sufficiently exclude gross weakness. However, don’t be afraid to test individual extremities for more subtle findings. You must ask them about numbness and attempt to determine its presence by touching or pinching the patient in all four extremities. Any abnormality should lead to immobilization.

The presence of intoxication becomes very subjective. Merely smelling alcohol on their breath does not mean they are intoxicated, but the most conservative approach would be to assume that any alcohol or drug use could interfere with the patients’ ability to answer your questions accurately and therefore prompt selective immobilization.

An altered level of consciousness is defined as any deviation from being fully awake and alert. Emotions such as anxiety and apprehension must also be taken into consideration when examining the patient. A report of a loss of consciousness, no matter how brief, should be considered an alteration even if the patient is not fully awake and alert. In the elderly or mentally challenged patient, the presence of dementia or impaired thought process limits your ability to perform an accurate exam.

Midline cervical tenderness is either a complaint by the patient that their neck hurts or a finding of pain on examining the neck. The examination is performed by palpating the entire cervical spine. While maintaining manual immobilization, run your finger down the posterior cervical spine along the spinous process from the base of the skull to the level of the shoulder blades. In this way you can be sure you have felt the entire cervical spine. Once that is complete, ask the patient to gently turn their head from side to side, stopping if they experience pain. Have them look up, then down, repeating the same instructions. Once all of these criteria has been met, you may safely decide not to immobilize the patient and can address any other injury or complaint.

Putting this all together into a protocol would look like this chart which is adapted from the 5th edition of Mosby’s Pre Hospital Trauma Life Support .   This protocol  incorporates the NEXUS criteria and the potential influence of mechanism of injury and extremes of age. Most important is the caveat "Use clinical judgment, if in doubt, immobilize."

Why not just immobilize everyone?
Certainly the safest thing to do, at least from a liability perspective, would be to immobilize everyone. But is that the best care? Immobilization is uncomfortable. It takes time and will increase your scene time. It increases the likelihood that the patient will be subjected to unnecessary x-rays and it can interfere with your ability to treat the patient’s other complaints. Further, if the patient vomits, it is difficult to maintain their airway and for the elderly and obese, it can compromise their breathing. Like everything in medicine we must weigh the good with the bad.

So where do you go from here?
If you think this is something your service should consider, I suggest you first meet with your medical director to discuss the issue. Provide him (or her) with the literature and give him time to research it for himself. If he still has reservations, suggest implementing it with a strong quality improvement program such as having the ED physicians determine whether they would or would not have immobilized the patient. For this to work they must make that assessment based on the same criteria you did and not after getting a bunch of x-rays and CAT scans. You could also prepare a worksheet to use in the field to record your findings and the criteria that you used in making your decision. Once your medical director agrees, it is vital that training be developed covering spinal cord injury in general and the specifics of how to assess each and every criteria. As stated earlier, it is critical that all five criteria be assessed before deciding not to immobilize the patient since any one of the five may be the only indicator of an underlying problem.

Summary
As medicine moves further along towards science, it is important that we make changes to our practice based on sound research. NEXUS and other similar projects is one of the best examples of how to apply that principle. Examine the problem, suggest a solution, and measure the effect. As more data is collected, I believe that we will learn that EMTs can safely apply the same assessment principles in the field that are used in the hospital and ultimately our patients will benefit from both.

Suggested Reading

1. Domeier RM: "Position Paper, National Association of EMS Physicians: Indications for prehospital spinal immobilization," Prehospital Emergency Care. 3(3):251-253, 1999

2. Domeier RM, Evans RW, Swor RA, et al: "Prehospital clinical findings associated with spinal injury," Prehospital Emergency Care. 111-15, 1997

3. Goldber W, et al: "Distribution and patterns of blunt traumatic cervical spine injury." Annals of Emergency Medicine. 38:17-21, 2001

4. Hendey GW, et al: "Spinal Cord Injury without Radiographic Abnormality: Results of the National Emergency X-Radiography Utilization Study in Blunt Cervical Trauma." Journal of Trauma. 53(1):1-4, 2002

5. Hoffman JR, Wolfson AB, Todd K, Mower WR: "Selective cervical spine radiography in blunt trauma: methodology of the National Emergency X-Radiography Utilization Study (NEXUS)." Annals of Emergency Medicine. 32(4):461-9, 1998

6. Holmes JF, et al: "Epidemiology of thoracolumbar spine injury in blunt trauma." Academic Emergency Medicine. 8(9):866-72, 2001

7. Panacek EA, et al: "Test performance of the individual NEXUS low-risk clinical screening criteria for cervical spine injury." Annals of Emergency Medicine. 38(1):22-5, 2001

8. Stroh G, Braude D: "Can an out-of-hospital cervical spine clearance protocol identify all patients with injuries? An argument for selective immobilization." Annals of Emergency Medicine. 37(6)6098-615, 2001

9. Ullrich A, et al: "Distracting painful injuries associated with cervical spinal injuries in blunt trauma." Academic Emergency Medicine. 8(1):25-9, 2001

10. Viccellio P, et al: "A prospective multicenter study of cervical spine injury in children." Pediatrics. 108(2):E20, 2001