You are working a busy overnight shift when you see EMS bring in a “trauma packaged” patient – a young, healthy-appearing female, on a hard backboard and with a C-collar in place. Per their report, she was the restrained driver of a vehicle struck from behind at a low rate of speed while stopped at a red light. The patient denies LOC, but is endorsing pain in her neck and all the way down her back. She is complaining that the backboard is uncomfortable and making her back pain worse.
What are the indications for prehospital rigid spine immobilization? Could it have been deferred in this patient?
Despite the dogmatic and traditional use of rigid backboards for extrication and transport of patients with possible blunt traumatic injury of the spine, it is not an altogether benign intervention. The discomfort associated with bumpy ambulance rides while secured to a rigid board may worsen a patient’s initial presentation to the ED providers such that unnecessary spinal imaging is ordered. Prolonged transport times on rigid boards have been associated with pressure sore formation and respiratory compromise.
The use of rigid spine immobilization by prehospital providers has become based largely on mechanism of injury and concern for possible spinal cord compromise, rather than being based on signs or symptoms of spinal injury itself. This is the opposite of how diagnosis of such injuries is handled once the patient arrives to the ED. As the validation studies of the NEXUS and Canadian C-spine rules have shown, the risk of a C-spine fracture in a patient with normal mental status and without clinical signs or symptoms of spinal cord injury or distracting injury is vanishingly small.
With this in mind, the National Association of EMS Physicians (NAEMSP) and the American College of Surgeons Committee on Trauma published a position paper in the journal Prehospital Emergency Care entitled “Indications for Prehospital Spinal Immobilization.” This paper (and the accompanying resource document) outlines who should and should not be immobilized based on best evidence.
To begin, patients must first be assessed for a mechanism of injury capable of causing spinal cord injury. This is somewhat open to interpretation by EMS providers, and can vary for different patient populations (i.e., a fall from standing would be a very low-risk mechanism for healthy young adult male but much higher risk in an elderly, frail female). The document specifically addresses penetrating wounds, based on evidence published in a paper in the Journal of Trauma in 2010. Basically, if a penetrating wound to the head, neck, or torso does not obviously affect the area of the spine and is not associated with evidence of spinal injury (including focal neurologic deficits), there is no need for rigid immobilization.
If the mechanism is determined to be a risk for spinal cord injury, the EMS provider must then perform a spinal assessment, which is largely derived from the NEXUS and Canadian rules for C-spine imaging. The spinal assessment is “positive” if there is any midline tenderness, palpable/visible midline deformity, or a new neurologic deficit. Immobilization must also be considered for those in which a spinal assessment is unreliable. This includes patients with altered mental status, who are intoxicated with alcohol or drugs, who have a painful distracting injury (by NAESMP criteria, a long bone fracture proximal to the wrists or ankles), or who are otherwise unable to fully participate in the exam due to a language barrier or due to age (i.e., pre-verbal pediatric patients).
If this assessment is negative, NAESMP recommends a C-collar should still be placed if the patient is over 65 (due to increased risk of C-spine injury in this population), but the patient does not require further spinal immobilization and can be transported in position of comfort. Obviously, a C-collar should be placed on any patient if there is midline tenderness in the C-spine.
Interestingly, a study from the Journal of Emergency Medicine published in 2013 reported data from a high-speed infrared motion analysis of healthy volunteers that showed those who extricated themselves with a C-collar in place had less spinal motion than those who were told to hold still while EMS crews attempted extrication themselves. Thus, if the patient is able to extricate themselves and able to ambulate, they should be allowed to do so. If their spinal assessment is positive, they can then be secured to the stretcher with seatbelts, which has been shown to be as effective at immobilizing the T- and L-spine as a rigid backboard. If the patient cannot self-extricate, they can be extricated using standard equipment and transported to the stretcher via a hard backboard. However, he or she should be logrolled off the backboard once reaching the stretcher to minimize time spent on the hard board. The safety of this approach is reinforced by data from other studies which have shown an extremely remote risk of significant (i.e., surgical) T- or L-spine injury in restrained persons in low-risk MVCs.
Remember that securing to the stretcher is an effective mode of spinal immobilization. Rigid backboards should probably be reserved for transfer of a nonambulatory patient from the scene to the stretcher, and should be removed as soon as possible.
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Kindly contributed by Sam Smith, PGY-3.