Indications for Spinal Immobilization

The most common scenario for prehospital spinal immobilization is an injury sustained during a motor vehicle collision. All-terrain vehicles, automobiles, snowmobiles, motorcycles, and other off-road vehicles are the most common causes of high-force spinal trauma in the wilderness setting. Falls and other high-force mechanisms are also concerning. Worrisome symptoms include spine pain or palpable tenderness, altered mental status, neurologic complaints, head injury, extremes of age, or an unreliable examination that involves a distracting injury, alcohol or drug use, or a communication barrier⁶ (Box 19-2).

Spinal immobilization is intended to prevent worsening of an existing spinal cord injury or the creation of a spinal cord injury in the case of a ligamentous disruption. The medical literature has multiple reports of worsening neurologic deficits after patients with spinal cord injuries are moved.^6,34,35 Extreme settings mandate a different interpretation of “urban” recommendations to fit the survival wilderness scenario. Wilderness data are limited, so prehospital spinal immobilization is prudent when practical.

Spinal immobilization is not performed without reservation. Backboards and collars may increase discomfort. Airway management may be restricted and evacuation times increased with spinal immobilization. However spinal immobilization remains the standard of care when practical in the wilderness setting.¹² Further research is indicated to better classify appropriate indications and to further assess the risk-benefit ratio for spinal immobilization in the wilderness.

Cervical Spine Immobilization

High cervical spine (C-spine) injuries have great potential for morbidity and disability. The goals of C-spine immobilization are to minimize movement and maintain a “neutral” alignment. Standard C-spine immobilization is performed with a hard collar in conjunction with a backboard and lateral support devices. The modern standard cervical collar has five contact points and makes use of the head, C-spine, and thorax. The thorax contact points include the trapezius muscles (posterior), clavicle, and sternum (anterior). Hard collars alone do not adequately limit cervical motion. Backboards and lateral support devices are required in conjunction with a hard collar (Figures 19-3 and 19-4). The patient’s neck requires manual stabilization in a neutral, in-line position until he or she is fully immobilized. Standard emergency medical services equipment includes lateral support devices (foam or plastic). In the wilderness setting, these devices can be improvised by rolling clothes, sheets, or blankets and placing them on both sides of head while securing everything in place with tape¹⁷ (see Figure 19-2).

FIGURE 19-3 Standard hard cervical collars.

(Courtesy Laerdal Medical Corporation.)

FIGURE 19-4 A to C, Different lateral support devices. D, Complete spinal immobilization.

(Courtesy Laerdal Medical Corporation.)

Cervical Spine Application

The application of a C-spine immobilization device depends on the position in which the patient is found and the device that is available. Universal application diagrams are generally helpful with regard to in-line stabilization, neutral neck alignment, chin positioning, and collar placement. Diagrams for application of C-spine collars on both upright and supine patients are easily referenced and generally intuitive (Figure 19-5). Diagrams for application of improvised C-spine collars or C-spine collars on patients who are found in sitting positions are also helpful (Figures 19-6 to 19-9; Figure 19-8, online).

FIGURE 19-5 Full spinal immobilization from a standing position. A, Step 1: Manual stabilization. B, Step 2: Apply a rigid collar. C, Step 3: Insert a long backboard. D, Step 4: Center the backboard. E and F, Step 5: Rescuers grasp the board with the use of a handle that is higher than the patient’s armpit. G, Step 6: Slowly lower the patient. H, Step 7: Fully immobilize the torso and then the head and neck.

(From Elling R, Politis J: Backboarding the standing patient, JEMS 12:9, 1987. Used with permission.)

FIGURE 19-6 Improvisational “horse collar.”

(Courtesy Ferno-Washington, Inc.)

FIGURE 19-7 Improvised cervical spine collar from a SAM splint. A, Fold 36-inch splint 5 inches from the end. B, While bracing the thumbs on either side of the fold, pull the edges to create a V-shaped chin rest. C, Place the chin rest below the patient’s chin, and place the rest of the splint loosely around the patient’s neck. D, Bring the end forward and down in an oblique direction until it touches the chest. E, While supporting the chin, bring the chest portion of the splint around the chin to create a chin post. Squeeze to deepen the chin post. F, Insert the index fingers on either side of the splint and pull. G, Squeeze to create lateral posts to ensure a snug fit. H, Squeeze the back of the splint to create more stability. I, Fold up any excess splint and secure it with wrap or tape.

(Courtesy SAM Medical Products.)

FIGURE 19-9 A, Kendrick Extrication Device (KED). B, Manual in-line stabilization of the cervical spine with the KED slid behind the patient. C, Applied KED with cervical collar in place. D, Patient transferred to long board.

(Courtesy Ferno-Washington, Inc.)

FIGURE 19-8 Improvised cervical spine collar fashioned from a SAM splint.

(Courtesy Alan Gianotti, MD.)

Special Considerations

Special populations require accurately sized equipment. This includes people with extra long or short necks for which a standard cervical hard collar is not effective. Children who are less than 8 years old are at risk for further injury when immobilized on a standard backboard because of a proportionately large head, which may cause increased flexion during a collision.³⁶ Modifications to counter this anatomic feature include raising the shoulders to the level of the head by placing a pad underneath the shoulders (Figure 19-10). This should be considered for all children who are on backboards.^28,29

FIGURE 19-10 Backboard considerations and increased cervical flexion for children who are younger than 8 years old. A, A young child immobilized on a standard backboard. Note how the large head forces the neck into flexion. Backboards can be modified by B, an occiput cutout or C, a double mattress pad to raise the chest. The actual clinical consequences of this observation are unknown.

(Modified from Herzenberg JE, Hensinger RN, Dedrick DK, et al: Emergency transport and positioning of young children who have an injury of the cervical spine, J Bone Joint Surg Am 71:15, 1989.)

Improvisational techniques

The key ingredients to an improvisational C-spine device include maximizing stability and fit while limiting airway compromise and allowing access for mouth opening, thus limiting aspiration risk.¹⁴ A “horse collar” technique involves a towel, blanket, or other available and malleable material rolled to the desired thickness and placed underneath the patient’s neck. The ends are then crossed over the patient’s chest and secured. As with the cervical hard collar, the patient’s C-spine is maintained in a neutral position during application and for as long as possible afterward by manual in-line stabilization^2,6 (see Figure 19-6).

A structural aluminum malleable (SAM) splint can also be molded into a C-spine collar. Studies have shown it to be as effective as a Philadelphia collar, with the advantage of being small, lightweight, versatile, and portable. These characteristics are advantageous in the wilderness setting²⁶ (see Figure 19-7).

Complications of Cervical spine stabilization

Studies have shown that C-spine collars cause increased intracranial pressure, which may be clinically significant for patients with head injuries. Therefore hard cervical collars should be removed immediately after exclusion of a C-spine injury, especially among patients with head injuries. C-spine collars may also be contraindicated in patients with penetrating neck injuries, because they may interfere with management of neck wounds or even conceal these wounds. Penetrating wounds to the spinal cord are rare. Cervical immobilization creates the real possibility of causing greater morbidity than protection.^18,19

Thoracolumbar Immobilization

A full-length backboard best accomplishes immobilization of the thoracolumbar spine. In addition, a cervical collar, lateral neck stabilizers, and backboard straps are essential for full spinal immobilization. If the patient is already upright, standing, or lying supine, application of a full-body backboard is straightforward, as described later in this chapter. However, with the suspected cervical injury of a seated patient, an intermediate device is required. There are many forms of this short board, such as a Kendrick Extrication Device (see Figure 19-9). Short boards are applied only after manual in-line stabilization and cervical collar placement. When the short board is in place, the patient can be safely transferred to a full backboard device.⁶

Strict contraindications for spinal immobilization are few but include emergency evacuation from an unsafe environment. Examples of such environments, with the risk of impending danger, include toxic spills, fire hazards, congested traffic areas, and other situations in which the application of an immobilization device would delay immediate evacuation to safety. In these dangerous situations, expedited removal with manual cervical stabilization is advised.²¹ When the patient is in a safe location, full spinal immobilization should be applied.

Choices for full-body splints include hard backboards, scoop stretchers, and full-body vacuum splints (Figures 19-11 to 19-13). Full-body hard backboards are used for their ease of application, availability, and effectiveness. Unfortunately, their size and weight make them undesirable for backcountry use, so they are often improvised in the field. Secured straps minimize spinal movement during transport. These are especially important with vomiting patients, when the airway is potentially compromised and a quick change of position is required to allow for removal and drainage of emesis.⁶ Hard backboards are uncomfortable. Spinal pain that is induced by a backboard may be misinterpreted, and this can complicate and delay therapy.¹⁶

FIGURE 19-11 Standard rigid splint.

(Courtesy Laerdal Medical Corporation.)

FIGURE 19-12 Example of a full-body vacuum splint used for wilderness rescue.

(Courtesy Sheri Trbovich and the Weber County Sheriff Department, Utah.)

FIGURE 19-13 A, Scoop stretcher. B, Stretcher placed beside the patient. C, Stretcher slid under the patient. D, Stretcher locked in place with straps secured.

(Courtesy Ferno-Washington, Inc.)

Vacuum splint devices offer certain advantages over rigid hard backboards. They can be applied more quickly, and are significantly more comfortable. They also offer a similar degree of spinal immobilization.²⁰ During mountain rescue, vacuum splints are the preferred device for total spinal immobilization (see Figure 19-12).

Full Spine Immobilization

From a supine (lying) position and after the placement of a cervical collar, the patient is logrolled and placed onto a board or vacuum splint. Three people are required to transfer a patient onto a board. The first person is positioned at the head and applies in-line stabilization, the second is at chest level, and the third is at pelvis level. On the command of the person at the head, the patient is rolled onto his or her least-injured side. The board is then slid underneath the patient while the back is evaluated for injuries. Body straps and lateral neck stabilizers are then placed.⁶ Logrolling is not required with scoop stretchers, thereby minimizing spinal movement (see Figure 19-13). Full spinal immobilization can also be applied to a standing patient (see Figure 19-5). Complications of full spinal immobilization are listed in Box 19-3.