Prehospital Immobilization

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Chapter 46

Prehospital Immobilization

Anne Klimke and Molly Furin

Modern emergency medical service (EMS) was created in 1966 as a result of the National Highway Safety Act. Since then, provision of medical care in the prehospital setting has undergone considerable change. Today’s EMS providers can start intravenous lines, administer intravenous medications and fluids, and perform lifesaving procedures. Nonetheless, the task of immobilizing the spine, pelvis, and extremities has remained a primary EMS function. This chapter reviews basic prehospital immobilization techniques and equipment, including spinal immobilization, pelvic stabilization, extremity splinting, and removal of protective equipment.

Spine Immobilization

Background

The first recommendations for spinal immobilization following blunt trauma came from the American Academy of Orthopaedic Surgeons in 1971.¹ These guidelines called for spinal immobilization of patients with symptoms or physical findings suggestive of spinal injuries.^1,2 Since then, recommendations for spinal immobilization have evolved considerably. During the 1980s and 1990s, indications for spinal immobilization were based primarily on the mechanism of injury, regardless of the presence or absence of symptoms or physical findings suggestive of a spine injury.^2,3 This resulted in routine prehospital spinal immobilization for all but the most trivial injuries and an abundance of unnecessary radiographs. Such wide-scale prehospital immobilization was initiated despite scant scientific evidence of improved patient outcomes. As a result, efforts were initiated to determine whether historical or clinical data could reasonably identify who had and who did not have serious injuries that would theoretically benefit from prehospital immobilization.

Growing concern over the cost of cervical spine radiographs and excessive radiation exposure led to the development of easily applied low-risk criteria that could identify the vast majority of significant injuries in an attempt to safely reduce the overuse of cervical spine radiography.⁴ In early 2000, two large prospective studies validated the use of clinical criteria to rule out injury to the cervical spine in victims of blunt trauma.^5,6 These studies dramatically reduced the number of unnecessary cervical spine radiographs following blunt trauma and led some investigators to question the prehospital practice of spinal immobilization based solely on mechanism of injury.^2,7–9

In 1998, Hauswald and colleagues ⁷ published the results of a 5-year retrospective review comparing patients from Malaysia, where cervical spine immobilization was nonexistent, to patients from New Mexico, where cervical spine immobilization based on the mechanism of injury was standard practice. Based on their results, the authors concluded that out-of-hospital immobilization has little or no effect on neurologic outcome in patients with blunt spinal injuries.⁷ More recently, researchers sought to determine whether prehospital providers could apply a set of clinical decision rules (Box 46-1) to selectively immobilize patients after blunt trauma.^10,11 A 4-year prospective study in two Michigan counties found that the use of a selective immobilization protocol resulted in spine immobilization for most patients with spinal injury without causing harm to patients in which spine immobilization was withheld.¹⁰ A larger study in New York demonstrated that selective immobilization based on a statewide protocol resulted in only one nonimmobilized unstable cervical spine fracture in more than 32,000 patient encounters.¹¹ Several other trials supported the use of clinical criteria for cervical spine clearance by prehospital care providers and hence supported the safety of avoiding routine immobilization for injuries that are extremely unlikely to be clinically significant.^12,13

Although spinal fracture and spinal cord injury (SCI) can have devastating results, the incidence of such injuries in trauma patients is relatively low, about 2% to 5% in most reviews. Unfortunately, most final neurologic outcomes after spinal cord trauma can be prognosticated by the initial evaluation, and lifelong disability has been set by the primary insult, not by prehospital or emergency department (ED) interventions. Sundheim and Cruz ¹⁴ calculated that only 0.03% to 0.16% of all out-of-hospital trauma patients may be expected to have secondary SCI that may be helped by immobilization. The number needed to immobilize to prevent one secondary injury is between 625 and 3333 trauma patients, but wholesale dismissal of any benefit from immobilization is not justified. It is important to note, however, that despite zealous use of prehospital cervical spine immobilization and countless medical and legal attempts to prove worsening of injury from its absence, there is little scientific evidence quantifying the effect of spinal immobilization in trauma patients or the possible adverse effects of its application (Box 46-2). Simply stated, the effect of spinal immobilization on mortality, neurologic injury, spinal stability, and adverse effects in trauma patients remains uncertain by evidence-based medicine, and no randomized prospective trials have been conducted.

Box 46-2

Spinal Immobilization for Trauma Patients *

Spinal cord damage from injury causes long-term disability and can dramatically affect quality of life. The current practice of immobilizing trauma patients before hospitalization to prevent more damage may not always be necessary because the likelihood of further damage is low. From studies of healthy volunteers it has been suggested that patients who are conscious might reposition themselves to relieve the discomfort caused by immobilization, which could theoretically worsen any existing spinal injuries.

Authors’ Conclusions

We did not find any randomized controlled trials that met the inclusion criteria. The effect of spinal immobilization on mortality, neurologic injury, spinal stability, and adverse effects in trauma patients remains uncertain. Because airway obstruction is a major cause of preventable death in trauma patients and because spinal immobilization, particularly of the cervical spine, can contribute to airway compromise, the possibility that immobilization may increase mortality and morbidity cannot be excluded. Large prospective studies are needed to validate the decision criteria for spinal immobilization in trauma patients at high risk for spinal injury. Randomized controlled trials in trauma patients are required to establish the relative effectiveness of alternative strategies for spinal immobilization.

^*Published online January 21, 2009.

From Kwan I, Bunn F, Roberts IG. Spinal immobilization for trauma patients. Cochrane Database Syst Rev. 2001;2CD002803.

Clinical judgment remains an acceptable and prudent approach, and it is most logical to consider the mechanism of injury and initial complaints or findings of neurologic dysfunction as reasonable indications for spine immobilization in the prehospital setting. However, despite growing questions regarding the efficacy and safety of routine prehospital spinal immobilization and despite a lack of scientific evidence demonstrating improved patient outcomes, it remains common practice for prehospital providers to immobilize most patients with traumatic mechanisms. Consequently, emergency medicine providers should be familiar with the devices and potential complications associated with spinal immobilization.

Epidemiology

According to the National Spinal Cord Injury Statistical Center (NSCISC), an estimated 12,000 new, survivable SCIs occur in the Unites States annually.¹⁵ The NSCISC estimates that 265,000 people were living with SCI in the United States in 2010.¹⁵ Since 2005, the most common cause of SCI is motor vehicle collision, which accounts for just more than 40% of cases, followed by falls and acts of violence, primarily gunshot wounds.¹⁵ Sports such as American football, rugby, swimming and diving, gymnastics, ice hockey, track and field (specifically pole vaulting), cheerleading, and baseball all place participants at increased risk for spinal injuries.¹⁵ The cost of care in both the immediate and extended care setting can be exorbitant, especially among the young. The average lifetime cost of medical care for patients with SCI varies depending on the level of injury but ranges from 500,000 to more than 3 million dollars.¹⁵

Pathophysiology

The direction and strength of the injurious force may help predict the type of injury sustained. Generally speaking, the basic forces that can be exerted on the spine are flexion, extension, rotation, lateral bending, distraction (stretching), and compression (axial loading).16,17 Of course, complex mechanisms may exert multiple forces. For example, high-speed rollover motor vehicle collisions could easily exert all the aforementioned forces.

Injuries to the upper cervical spine (C1 and C2) (Fig. 46-1) occur more often in older, osteoporotic patients than in younger patients. The spectrum of injuries in the cervicocranium includes occipital condyle fractures, occipitoatlantal dislocations, dislocations and subluxations of the atlantoaxial joint, fractures of the ring of the atlas, odontoid fractures, fractures of the arch of the axis, and fractures of the lateral mass of the axis (Fig. 46-2). Involvement of the spinal cord at this high level can cause devastating neurologic injury, and it is reasonable to believe that many of these injuries are not reported because they result in death.¹⁸ Subaxial cervical spinal injuries involving C3-7 have a broad spectrum of clinical implications. Approximately two thirds of cervical injuries causing quadriplegia occur within the lower cervical spine, with fractures occurring most often in C6 and C7 and dislocations most commonly occurring between C5-6 and C6-7.¹⁹

Figure 46-1 The human spinal column.

Figure 46-2 Type III odontoid (C2) fracture (arrow). A common scenario for this type of injury is an elderly woman who falls from a standing height.

The orientation of the facets in the thoracic spine allows significantly less flexion and extension than in the cervical or lumbar spine. In addition, the free space between the thoracic spinal cord and the borders of the spinal canal is relatively small, and the blood supply is less robust. These factors increase the susceptibility of the spinal cord to injuries at this level. At the thoracolumbar junction there is an acute transition in stability because of the loss of rib restraint, which increases the risk for flexion-extension and rotational injuries. Disk size and shape also change, thus making this section of the spine particularly susceptible to injury. Approximately half of all vertebral body fractures and 40% of all SCIs occur between T11 and L2.²⁰

The lumbar spine is protected only by the abdominal and paraspinous musculature, which makes it subject to distraction and shear forces, such as seen with lap belt injuries. There is also a higher prevalence of compression and burst fractures in the lumbar spine. These fractures commonly occur when axial loading forces straighten the natural lordosis at the moment of impact.²¹

The sacrum forms both the terminal portion of the spine and the central portion of the pelvis, which gives it added stability and makes isolated sacral fractures uncommon. Such fractures are usually caused by direct trauma or falls from a height or occur as a result of sacral insufficiency secondary to osteopenia, chronic steroid use, or previous pelvic irradiation. More often, sacral fractures occur as a result of high-energy mechanisms and are associated with major pelvic disruption.²²

Indications

The National Association of EMS Physicians recommends spinal immobilization of prehospital trauma patients who sustain an injury with a mechanism that has the potential for causing spinal injury and who have at least one of the following clinical criteria: altered mental status, intoxication, a distracting painful injury (e.g., long-bone fracture), a neurologic deficit, and spinal pain or tenderness.²

Extremes of age and the presence of communication barriers (e.g., language, hearing impairment) may affect the ability to accurately assess the patient’s perception and communication of pain and should lower one’s threshold for spinal immobilization.2,3 It is also important to remember that serious cervical cord injuries can occur in the absence of demonstrable fractures. SCI is common in elderly patients with cervical spondylosis, in whom an arthritic osteophyte may sever a portion of the cord as permanently as a fracture or dislocation. In such cases there may be little subjective pain, and the mechanism of injury may appear seemingly minor.²³

Contraindications

Spinal immobilization is contraindicated (or may require modification) when its use could harm the patient, when it is logistically impossible, or when the scene is unsafe (Box 46-3). Good clinical judgment, not blind application of protocols, is essential. For example, if application of a cervical collar will cause or mask airway compromise secondary to swelling, an expanding hematoma, or other process, it should not be used. Obviously, if a patient requires a surgical airway, the EMS provider will need immediate, unencumbered access to the anterior aspect of the neck. Sometimes preexisting airways (e.g., tracheotomy tube) and associated equipment prohibit proper application of a cervical collar. These situations can often be managed with an improvised cervical immobilizer, such as a collar fashioned from a towel roll or prolonged manual stabilization without traction.

Box 46-3 Contraindications to Prehospital Spine Immobilization *

May be potentially harmful (e.g., prevents identification of airway compromise)

Need for a surgical airway

Presence of a preexisting airway (e.g., tracheostomy tube)

Obesity

Impaled objects

Chronic respiratory diseases (e.g., congestive heart failure) or acute respiratory distress from any cause (e.g., ascites)

Altered mental status (e.g., intoxicated patients)

Cervical dislocation or anatomic limitation because of preexisting conditions (e.g., ankylosing spondylitis)

Logistically impractical (e.g., mass casualty incident)

Unsafe scene:

l. Exposure to hazardous material, fire, or smoke

l. Building explosion or collapse

l. Deep or fast moving water that poses a risk for drowning

l. Risk for injury from assault (e.g., gunshot, stabbing, blunt trauma)

l. Any other circumstance that the emergency medical service provider deems an immediate danger to the life or health of the patient, provider, or both

^*Situations listed in this table can often be managed with an improvised cervical immobilizer (e.g., towel roll or manual in-line stabilization [see text for details].

Other conditions that may prevent spinal immobilization or require modification of standard techniques and equipment (e.g., towel roll and manual in-line stabilization) include obesity, impaled objects, underlying respiratory problems or acute respiratory distress (e.g., from congestive heart failure or ascites), altered mental status (e.g., combative patients because of intoxication or psychiatric illness), and cervical dislocation with fixed angulation or anatomic limitations from preexisting conditions such as ankylosing spondylitis and kyphosis.²⁴

There are also scenarios when spinal immobilization is logistically difficult or impossible. In a mass casualty incident, for instance, spinal immobilization of multiple victims with a low probability of spinal injury is impractical (Fig. 46-3).

Figure 46-3 Though often performed as a reflex for even minor trauma that has little or no chance of associated spinal injury, the true value of formal spinal immobilization in preventing initial, further, or secondary neurologic damage remains uncertain by evidence-based medicine, and no randomized prospective trials have been conducted. It is always prudent to be overly cautious, but during a mass casualty incident such as a train accident, spinal immobilization of multiple victims with a low probability of spinal injury may not be practical and may delay other more pressing interventions if resources are limited.

Finally, spinal immobilization may need to be delayed or modified when the scene poses a significant threat to the patient or providers (see Box 46-3).¹⁶ In these situations, the prehospital provider may opt for rapid extrication of the patient from the scene without immobilization of the spine (Fig. 46-4).

Figure 46-4 Spinal immobilization may need to be delayed or modified when the scene poses a significant threat to the patient or providers, such as evacuating a wounded soldier during a sniper attack. Rescue from a toxic or poisonous environment, such as hydrogen sulfide or carbon monoxide, is a similar situation.

Equipment

Cervical Collars

Traditionally, cervical collars have used a four-point support structure at the bottom of the collar—at the two trapezius muscles posteriorly and at the two clavicles anteriorly. Most modern collars are modified rigid head-cervical-thoracic devices that use the sternum as a fifth support structure. Current collar designs support the head with winglike flaps on the collar’s upper posterior edges. Anteriorly, the collar supports the mandible. The collar’s flaring design generally prevents compression of the thyroid cartilage and cervical vessels, even when applied firmly. Some collars come as single units that conform to the neck once a chin support has been assembled, whereas others come in two parts, with a front and a back that are secured with Velcro (Fig. 46-5). Some manufacturers have developed collars that have adjustable heights to account for different neck lengths. Soft collars, though comfortable, have no role in spinal immobilization because they provide minimal support and do not reduce cervical motion to any significant degree.^25,26

Figure 46-5 Cervical collars. A, Philadelphia collar. This two-piece, high-type collar comes in four sizes. The collar supports the head in a dish-shaped contour that is formed when the front and rear halves are joined by Velcro fasteners. When properly sized for a patient, this collar provides excellent support. When applied too tightly, it tends to force the mandible backward and can cause compression of the thyroid in some patients. B, Stifneck collar. This collar is made of high-density polyethylene (a hard material) and padded with semiflexible foam margins. Note the low-reaching anterior panel, which contacts the sternum for additional support.

Investigators have attempted to evaluate cervical collars in an objective fashion. The accepted “gold standard” for comparison is the halo brace, which restricts motion to 4% flexion-extension, 1% rotation, and 4% lateral bending.²⁷ Unfortunately, even the best cervical collars (when used independently) restrict flexion and extension by only 70% to 75% and overall neck movement by 50% or less.²⁸ A number of studies have evaluated neck motion in volunteers immobilized supine on a backboard with various collars in place.^{25,26,29–32} Although these studies demonstrated small differences among some of the collars, overall they merely confirm the fact that cervical collars alone are inadequate to immobilize the cervical spine completely. Thus, it is important to keep in mind that for effective cervical spine immobilization, differences among the various types of cervical collars are less important than proper application, a snug but comfortable fit, and most importantly, use of adjunctive equipment.

Cervical Extrication Splints

A large variety of short spine boards (Fig. 46-6) and intermediate-stage extrication devices are available for prehospital use. Generally, these devices are manufactured from rigid lightweight material. They have a narrow board design that permits easy application in automobiles or confined spaces and are constructed with multiple openings along the edges to allow a variety of strapping options. Ideally, these devices should also be translucent so that radiographs can be readily obtained in the ED, and they should allow repeated use and easy clean up. When not in use, store extrication splints with their straps secured in their individual retainers to reduce the likelihood of becoming entangled during application.

Fig. 46-6 Cervical extrication splints. A, Rigid short boards. B, Kendrick Extrication Device. (Courtesy of Ferno-Washington, Inc., Wilmington, OH.)

Application of a cervical extrication splint should not produce unnecessary movement or change the position of the head, neck, shoulders, or torso. In conjunction with a good cervical collar, a properly applied cervical extrication splint should effectively limit flexion, extension, and lateral and rotational motion of the head, neck, and torso.

One commonly used device that meets all these criteria is the Kendrick Extrication Device (KED) (see Fig. 46-6B). This device consists of two layers of nylon mesh impregnated with plastic and sewn over plywood slats to provide rigidity. It has a nylon loop behind the patient’s head that is continuous with the pelvic support straps for additional strength. Part of its anterior thoracic panels can be folded backward to fit obese, pregnant, or pediatric patients.³³ When properly applied, the KED is a snug-fitting, highly adaptable immobilizer that can be used in even the most adverse circumstances.

When patients require immobilization or extrication (or both) in more difficult or treacherous environments, many EMS providers prefer the LSP half-back, which resembles a KED but is more rugged and durable. In addition to providing spinal immobilization, it also acts as a harness and can be used for hauling patients over flat surfaces, as well as vertical lifts (Fig. 46-7).³⁴

Figure 46-7 The LSP half-back. This cervical extrication splint resembles a Kendrick Extrication Device but is more rugged and durable. In addition to providing spinal immobilization, it also acts as a harness that can be used for hauling patients over flat surfaces and vertical lifts.

Mosesso and coworkers ³⁵ compared six prehospital cervical immobilization devices and concluded that the devices were similar in their ability to immobilize the cervical spine.

Full-Body Spine Immobilizers

Full-Body Spine Boards (Backboards): Backboards are made of wood or plastic composites and can be either rectangular or tapered in shape (Fig. 46-8A). Most rescuers prefer the tapered type because it takes up less horizontal room when angled into a narrow opening or doorway. In addition, the slight narrowing of these boards on either end enhances the effectiveness of strapping.

Figure 46-8 Full-body spine boards (backboards.)

Most backboards have strategically placed openings along the edges that can be used to secure head-stabilizing devices, strap the patient to the board, or lift the patient. Many also feature runners, usually about 2.5 cm thick, on their undersides that serve both as stiffeners and as spacers. They raise the board slightly off the ground so that rescuers can get their fingers under the board during lifting. The runners, however, may make it more difficult to slide a patient onto the board.

Advantages of boards over full-body splints include their ease of storage, low cost, and extreme versatility. The backboard can be used to slide a victim out of an automobile or to protect a victim during removal of a windshield.

The biggest drawback of using backboards as immobilizers is lack of patient comfort. Board splints, as a class, are the least comfortable of all immobilizers. Studies have demonstrated that spinal immobilization on a hard backboard causes head, back, and jaw pain.36,37 Pain in these areas may become severe if patients are left immobilized on these boards for extended periods.^38–40 In addition, the pain caused by application of a backboard may be difficult to separate from other sources of pain in a trauma patient and might lead to unnecessary and costly radiographs.² Discomfort may be minimized by using padding at points of contact between a bony prominence and the board. This concept was reaffirmed by Hauswald and colleagues,⁴¹ who found that increasing the amount of padding on a backboard decreases the amount of ischemic pain caused by immobilization.

Scoop Stretchers: If an injured person has to be extricated from a tight location, a smooth backboard is probably the best device to immobilize and move the victim. If the victim is not in a tight location, the scoop stretcher is an ideal field immobilizer (see Fig. 46-8B). In fact, one recent study found that using the Sterno scoop stretcher caused less spinal motion than did a traditional long backboard and logroll technique.⁴²

The scoop stretcher is designed to split into two or four pieces. It is comfortable, rigid, and adaptable to patients of various lengths and provides unobstructed radiographic transparency of the entire spine. If necessary, it can be applied almost instantly or removed without disturbing the position of the victim. The scoop stretcher also provides good lateral stability because of the troughlike shape of its top surface, and it is stable enough to be used for carrying. For optimal protection of a potential spinal injury, the spine should be completely immobilized (e.g., cervical collar, lateral supports, and secure strapping) and the scoop stretcher should be placed on a backboard before moving the patient. In addition, the scoop stretcher should be carefully reassembled to avoid trapping clothes, skin, or other objects between interlocking parts.

The scoop interferes slightly with the ischial section of a half-ring traction splint but works well with Sager-type devices. The Ferno-Washington model 65 scoop (Ferno-Washington, Inc., Wilmington, OH) is the most widely used stretcher of this type. Other devices such as the Combi-Carrier (Hartwell Medical, Carlsbad, CA) and the Scoop EXL (Ferno-Washington, Inc., Wilmington, OH) offer lightweight polymer construction and additional spine support (see Fig. 46-8C and D).

Full-Body Splints: Various devices take the concept of full-body immobilization one step further than the spine board. One popular device is the Miller body splint, which consists of a polyethylene shell injected with closed-cell foam that is radiographically translucent and provides buoyancy in water (see Fig. 46-8E). This full-body splint features a removable head harness and a thoracic harness, as well as pelvic and lower extremity belts. The space between the lower extremities facilitates wrapping with bandage material in the event of fractures. In addition, it is shaped so that it can easily fit into a basket-type rescue stretcher. Similar spine immobilization systems are available for pediatric patients (e.g., Pedi-Pac, Ferno-Washington, Inc., Wilmington, OH).

An important innovation in the area of spine immobilization in the United States has been the vacuum mattress splint (e.g., EVAC-U-SPLINT, Hartwell Medical, Carlsbad, CA, and Immobile-Vac, MDI, Gurnee, IL) (see Fig. 46-8F). It consists of a vinyl-coated polyester envelope filled with thousands of 1.1-mm-diameter polyester foam spheres. A manual or electric vacuum pump is used to evacuate the interior to a pressure of about 0.25 atm. This reduction in internal pressure causes the mattress to conform to the contours of the patient’s body. Vacuum splints have been shown to produce lower sacral interface pressure and lower mean pain scores than traditional hard backboards^37,43 and may provide better immobilization in patients with known SCI.^44,45 It should also be pointed out, however, that vacuum splints are larger and more cumbersome than backboards, thus making ambulance storage more difficult.

Lateral Neck Stabilizers: Lightweight objects such as blocks (10 × 10 × 15 cm) made of medium-density foam rubber are commonly used to provide additional lateral stabilization of the head and neck. Foam blocks are inexpensive and disposable and do not slip on the backboard. Disposable cardboard devices that have the same advantages as foam blocks are also available (Fig. 46-9A).

Figure 46-9 Lateral neck stabilizers. A, The HeadBed, a cervical immobilization device made of a water-resistant corrugated board. B, Universal Head Immobilizer. (A, Courtesy of Laerdal Medical Corporation, Wappingers Falls, NY; B, courtesy of Ferno-Washington, Inc., Wilmington, OH.)

Another commercial device is the Universal Head Immobilizer. It is a lateral neck stabilizer designed to quickly and easily fasten the patient’s head to a scoop stretcher or spine board (see Fig. 46-9B). The Universal Head Immobilizer is made of a Herculite nylon and polyethylene foam platform fastened to the stretcher with Velcro straps. The lateral pillows are then attached to the nylon platform by means of large Velcro interfaces.

It should be noted that although sandbags are effective devices for lateral immobilization, they may cause significant movement of the neck if the board is suddenly tilted (e.g., to decrease the risk for aspiration in a vomiting patient). Therefore, their use is no longer recommended.

Foam Padding: Padding increases comfort and can help prevent further injury. It can also help support an injured extremity or impaled object or allow an obese or kyphotic patient to lie supine on a long backboard (Fig. 46-10).²⁹ Pregnant women may benefit from padding under the right hip to help shift the gravid uterus off the inferior vena cava and increase venous return.⁴⁶ Padding applied under the neck and shoulders prevents hyperflexion in children with large occiputs (Fig. 46-11) or in individuals wearing certain types of helmets (e.g., bicycle, motorcycle, rock climbing) that cannot be removed in the field.

Figure 46-10 Padding. Padding increases comfort and theoretically may prevent further injury. It can also help support an injured extremity or impaled object or allow an obese or kyphotic patient to lie supine on a long backboard.

Figure 46-11 A, Young child immobilized on a standard backboard. Note how the large head forces the neck into flexion. Backboards can be modified by an occiput cutout (B) or a double mattress pad (C) to raise the chest, the actual clinical consequences of which are unknown. (A-C, Adapted 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. 1989;71:15.)

Procedure

Cervical Spine Immobilization

It is important to remember that the continuous nature of the spinal column means that movement of one part of the column is transmitted to the other areas, so to protect the injured area the entire spine must be immobilized. This requires the head, neck, and torso to be fastened into a single common plane. Hence, in addition to a rigid cervical collar, the patient must also be secured to an intermediate spine-immobilizing device (e.g., short spine board, KED), a full-length spine board (e.g., backboard, scoop stretcher, full-body splint), or both (see later) to ensure complete cervical spine immobilization.

The first priority in cervical spine immobilization is providing manual in-line stabilization in the neutral position. This can be done with the patient standing, seated, supine, or prone and consists simply of placing both hands on the sides of the patient’s head to prevent flexion, rotation, or bending. Do not apply cervical traction because it can increase the risk for SCI, and be sure to maintain manual in-line stabilization during application of the cervical collar and until the patient can be fully immobilized in an intermediate-stage corset-type device or on a long backboard (see later in this section). Once the cervical spine has been manually stabilized in the neutral position, examine the neck for swelling, ecchymosis, deformity, bony tenderness, or penetrating wounds. Application of a cervical collar follows and is generally a straightforward procedure (Fig. 46-12). The rescuer’s intentions should be thoroughly explained to the patient throughout the procedure.

Figure 46-12 Cervical collar application.

Once the collar is in place, conscious patients should be cautioned repeatedly against movement of the head. Investigate any persistent complaints of pain or dyspnea by removal and possible replacement of the device while manual stabilization is maintained. The size of collar should be determined from the manufacturer’s suggested guidelines. For example, the Stifneck collar (Laerdal Medical Corp., Wappingers Falls, NY) is available in various sizes and uses the distance from the top of the shoulder to the chin to determine the appropriate size. Use the tallest collar that does not cause hyperextension. For extremely short necks, a special cervical collar such as the No-Neck (Laerdal Medical Corp., Wappingers Falls, NY) is recommended. In cases in which a cervical collar of the proper size is not available, an improvised device should be made from available material (Fig. 46-13).

Figure 46-13 Horse collar. Most extrication collars are available in three to five factory sizes. If a collar is not sized properly to fit a particular patient, it performs no function. Patients with extremely long necks or especially short ones can be immobilized by means of a horse collar fashioned from a blanket or towel. The blanket (or towel) is rolled to the thickness desired and slid under the patient’s neck while a bystander applies manual stabilization; the ends of the blanket (or towel) are then brought across the anterior aspect of the patient’s chest. (Courtesy of AtlantiCare Regional Medical Center, Emergency Medical Services, Atlantic City, NJ.)

It should also be remembered that application of a cervical collar should not be attempted until the patient’s head has been brought into a neutral position and manual in-line stabilization has been applied.²⁸ If the patient experiences cervical muscle spasm, increased pain, neurologic complaints (e.g., paresthesias, weakness), or airway compromise, immediately halt any further movement of the head and neck. In these situations, immobilize in the position that the patient was found by using an alternative technique (e.g., blanket, towel roll, manual in-line stabilization).

Thoracolumbar Spine Immobilization

Despite the presence of a field cervical collar, manual in-line cervical stabilization should be continued until the patient is fully immobilized with either a cervical extrication splint or a full-body splint (e.g., a backboard or vacuum stretcher). The immobilization technique used will depend on the patient’s position of origin.

Sitting Position: To immobilize patients who are in a sitting position, use a short backboard or commercially available cervical extrication device (e.g., KED). At least two rescuers should be present to apply an extrication splint to a sitting patient. Interestingly, a recent study by Shafer and Naunheim found that healthy volunteers who were allowed to extricate themselves from the front seat of a car and lie down on a long spine board while wearing a cervical collar had less spinal movement than did those who were placed in cervical collars and moved onto the board directly or after application of a KED.⁴⁷ Nevertheless, use of KEDs or short boards remains the most common method for vehicle extrication.

Open the device butterfly style and gently slide it behind the victim via a rocking motion (Fig. 46-14, step 1). If necessary, carefully rock the patient forward a few degrees to facilitate placement of the splint. Once behind the victim, free the splint’s pelvic support straps from their retainers and allow them to dangle at the patient’s sides. Next, bring the lateral thoracic panels around the chest just beneath the patient’s shoulders. Grasp these panels and slide the splint upward until the top edges of the panels firmly engage the patient’s axillae. Now use the thoracic straps to secure the splint, beginning with the middle strap, then the bottom strap, and finally the top strap (see Fig. 46-14, step 2).

Figure 46-14 Kendrick Extrication Device. Use of other short boards follows the same principles as depicted here.

This procedure may need to be modified depending on injuries and preexisting conditions. For example, patients with pelvic fractures may not tolerate placement of the pelvic support and bottom straps, and the gravid abdomen of a pregnant patient may prevent placement of the middle strap. The straps should be snug, but not so tight that they interfere with respiration.

Fasten the pelvic support straps next. They can be slipped one at a time beneath the patient’s lower extremities and brought directly beneath the pelvis with a back-and-forth motion. If the pelvic straps are not applied properly, considerable slippage may occur when the patient is lifted. Connect the free end of each pelvic strap to buckles located at the patient’s hip on the outside of the splint. Once a strap is ready to be buckled, it can be either attached to the buckle on its own side or moved across the patient’s lap and engaged with the opposite buckle. Most prehospital care providers prefer the latter method because it allows the patient’s knees to remain together without discomfort. It is also a good idea to pad the groin area when placing the pelvic support straps because these straps may cause the patient considerable discomfort.

Next, secure the head to the device (see Fig. 46-14, step 3). When using the KED, wrap the head panels snugly around the head and neck while another rescuer applies the diagonal head straps. It may be necessary to place padding behind the head to maintain a neutral position. Use the forehead as a point of engagement for one strap and the cervical collar for the other.

As a final step, tighten all buckles until the entire splint is firmly in place. The patient can now be moved. If the patient is to be lifted from a vehicle, bring the ambulance cot with a spine board on it as close to the patient as possible (see Fig. 46-14, step 4). While one rescuer supports the patient’s knees, the other rescuer uses the handholds on the splint to lift the patient. The patient should be rotated and laid in a supine position onto a backboard. Loosen the pelvic straps to allow the legs to be lowered onto the backboard. The legs can then be extended and secured to the backboard or left in the flexed position with a pillow placed under the knees for support.

Apply a lateral immobilizer to help prevent movement of the head and neck, and strap the body into place on the backboard. Once the patient is on the board, the thoracic straps of the cervical extrication splint may need to be readjusted.

Recumbent Position: A patient who is found in a recumbent position should be placed in a supine position, if not already in one. If repositioning is necessary, examine the back during the process. Physical examination, spinal immobilization, airway management, and transport are easier to accomplish with the patient in the supine position.

Patients who are found supine do not require the use of a cervical extrication splint. They should, however, receive initial manual in-line cervical stabilization and a cervical collar. The patient should then be fastened to a full-body spinal immobilizer, such as a scoop stretcher, backboard, or full-body splint.

Scoop Stretcher.: A patient who is in a supine position can be moved by means of a scoop stretcher. In a conscious patient, rescuers should explain that they are about to apply a scoop-type stretcher, which may be cold to the touch, beneath the patient’s body. Apply a cervical collar and maintain manual in-line cervical stabilization until the patient is completely secured to the stretcher.

Place the scoop on the ground next to the patient and open the latches that regulate its length. Adjust the length to fit the full length of the patient’s body and reengage (lock) the latches. Next, release the latches at each end and separate the stretcher into two halves. Place each half next to the patient. One rescuer then gently pushes half the stretcher under one side of the patient. In some cases it may be necessary to have another rescuer rock the patient to allow proper positioning. Repeat the procedure with the opposite half of the scoop until both halves are aligned beneath the patient. Engage the latch at the head of the device first. Then bring the lower ends together and engage the foot latch to complete the integrity of the stretcher. Strap the patient’s torso into place and immobilize the head with a suitable lateral neck stabilizer. The patient can then be lifted onto another device for transport (e.g., Stokes stretcher or backboard). After placement on another device, the scoop stretcher can be removed without disturbing the patient’s position, if necessary.

Full-Body Spine Boards (Backboards).: There are several ways of placing a patient onto a spine board. The precise technique used will depend on the space available and the position of the patient within that space. For lengthwise extrication, as from an automobile seat, the patient can be slid, either feet first or head first, onto the backboard. It is important that the patient be moved as a unit during this process. Place one end of the backboard on the seat or doorsill of the automobile. One rescuer stabilizes the opposite end of the board while at least two other rescuers lift and slide the patient’s body onto the board. Once the patient is secured to the board, slide the board out of the vehicle and onto a waiting stretcher. Maintain manual cervical in-line stabilization throughout the procedure and avoid spinal compression or traction.

When space permits, lateral extraction is preferred. If the patient is in the recumbent position, logroll or slide the patient onto the board. The logroll maneuver requires the presence of at least three rescuers. Position one rescuer at the patient’s head to apply manual in-line cervical stabilization (Fig. 46-15, step 1). It is this person’s responsibility to oversee and direct body movement throughout the procedure. Next, position the backboard next to the patient’s body (see Fig. 46-15, step 2). To minimize thoracolumbar movement, extend the patient’s arms at the sides with the palms resting on the lateral aspect of the thighs.⁴⁸ To keep the patient from reaching for a rescuer or object during transfer, some rescuers prefer to have patients cross their arms across the thorax. However, this maneuver has not been shown to prevent or minimize thoracolumbar movement. If one arm is injured, place the backboard against this side so that the patient can be rolled onto the uninjured extremity. Position the other rescuers on the side that the patient will be rolled toward, with one rescuer at the midchest level and the other at the legs. The rescuer at the chest should reach across the victim and take hold of the shoulder and hips while the other rescuer grasps the hips and lower part of the legs. When everyone is ready, the rescuer at the head gives the command to roll the patient onto the side (see Fig. 46-15, step 3). If possible, examine the patient’s back at this point. Slide the backboard under the patient, and when everyone is ready, the rescuer at the head gives the command to roll the patient back onto the board (see Fig. 46-15, step 4). Before applying straps, it is often necessary to center the patient on the board.

Figure 46-15 Full-body spine board (backboard): the logroll maneuver.

To safely center the patient on the long spine board, support the cervical spine, shoulders, and hips and slide the patient first caudally, then cephalad, in a zigzag pattern to avoid applying uneven lateral or rotational force onto the spine. Alternatively, during lateral extraction, a recumbent patient can be slid sideways onto the spine board. This improvised technique also requires the presence of three or four rescuers, one of whom can maintain control of the patient’s head and neck.

Various techniques can be used to secure a patient to the backboard. In addition to the standard thoracic, pelvic, and lower extremity straps, use of an abdominal strap significantly reduces lateral motion without compromising respiration.⁴⁹ Proper strap placement and firm contact between the straps and the patient are also important in limiting lateral motion (see Fig. 46-15, step 5).⁵⁰

After the body has been strapped to the board, the head can be secured. If necessary, padding can be placed under the occiput to maintain the head in the neutral position. Apply a lateral neck stabilizer (e.g., foam blocks, HeadBed device) and secure the head in place with tape or straps (see Fig. 46-15, step 6). Most taping techniques involve the use of one piece across the forehead and one piece across the cervical collar. Note that this method of securing a patient to a backboard is designed for horizontal lifting only.

Standing Position: A standing patient with a potential spine injury must be immobilized and placed in the supine position. One technique for placing these patients on a backboard that is quick, safe, and effective is presented here.⁵¹ Position the tallest rescuer behind the patient to manually stabilize the head while a second rescuer applies a cervical collar (Fig. 46-16, step 1). The first rescuer must maintain manual in-line cervical stabilization until the patient is completely secured to the board. Center the backboard behind the patient between the arms of the rescuer who is stabilizing the head and neck (see Fig. 46-16, step 2). Facing the patient, a rescuer on each side reaches under the patient’s arms and grabs the backboard by a handhold at or above the patient’s axillae (see Fig. 46-16, step 3). The patient’s elbows are then brought closer to the body. If additional personnel are available, position a rescuer at the feet to prevent the board from sliding out. Slowly tilt the patient back by lowering the head of the backboard (see Fig. 46-16, step 4). The rescuer at the head should step back during this process while maintaining the patient’s head and neck in neutral alignment. When the backboard is completely horizontal, secure the patient to the backboard in the usual fashion.

Figure 46-16 Full-body spine board: securing the patient from a standing position.

Pediatric Patients

Little information is available on the proper selection and application of spinal immobilization devices for children. Most of the data available were derived from studies of adults and might not be applicable to children. Half of the total growth in head circumference is achieved by the age of 18 months, thus giving children a disproportionately large head in comparison to the rest of the body. Before 8 years of age, these anatomic and developmental differences result in a higher incidence of upper cervical spine injuries (C1-2). Because injuries in this area are frequently unstable, proper cervical immobilization in the neutral position is critically important.

In the neutral position, the pediatric cervical spine is normally lordotic or extended.⁵² However, because the occiput is large, positioning the child’s body on a standard backboard may force the neck into flexion or a relative kyphosis. The clinical significance of this is currently unclear, but theoretically it may be hazardous for young children. Therefore, the standard backboard should be modified to adapt to the child’s larger head size. As a rough guide, the external auditory meatus should be on the same level as the midpoint of the shoulder. Suggested modifications include a cutout in the backboard that accommodates the occiput or a pad under the back at the level of the chest (see Fig. 46-11). If not modified, the standard backboard in conjunction with the disproportionately large head of a child may force the neck into hyperflexion and potentially aggravate an underlying cervical spine injury. Nypaver and Treloar⁵³ showed that all children required elevation of the back (mean height, 25.4 ± 6.7 mm) for correct neutral position on a spine board. Children younger than 4 years required more elevation than did those 4 years or older. It must be pointed out, however, that there have been no published reports of a cord lesion resulting from the use of standard immobilization techniques and equipment in children.⁵²

Complications

Cervical Immobilization

Improper application of a cervical collar can occur if the wrong size is used or too little care is exercised during placement. The best means of preventing either error is strong clinician involvement in training and continuing education of EMS crews together with vigorous feedback regarding correct and incorrect application. In addition, adherence to the manufacturer’s collar-specific recommendations for size and application should be emphasized.

A collar that is too small for a patient may be either too tight for the girth of the neck (with obvious complications) or too short to provide adequate immobilization. Too large a collar commonly results in hyperextension, which can exacerbate a preexisting spinal injury. Underlying spinal abnormalities from conditions such as ankylosing spondylitis, rheumatoid arthritis, or kyphosis can also contribute to exacerbation of injuries with cervical collar application.²⁴

Improper or prolonged application of an extrication collar may impede venous return and raise intracranial pressure (ICP).⁵⁴ Although the clinical significance of increased ICP produced by cervical immobilization is still unknown, two studies have confirmed that application of a rigid cervical collar causes a statistically significant and sustained rise in ICP.^55,56 Kolb and colleagues⁵⁵ reported a 24.8–cm H₂O increase in cerebrospinal fluid pressure in 20 adult patients undergoing lumbar puncture. Hunt and associates⁵⁶ reported a 4.6–mm Hg mean rise in ICP in 30 patients with severe traumatic brain injury. The largest rise in ICP was noted in patients with a baseline ICP higher than 15 mm Hg. The authors of these studies concluded that the elevation in ICP produced by cervical immobilization might have deleterious effects in patients with acute or sustained intracranial hypertension.^55,56

Long-term use of the Philadelphia extrication collar (Philadelphia Cervical Collar Co., Westville, NJ) as part of the treatment plan for an underlying cervical spine injury has been associated with pressure ulcers of the scalp.⁵⁷ Because some collars (e.g., Philadelphia and Stifneck) have been shown to exert higher capillary closing pressure at contact points, it is suggested that collars with favorable skin pressure patterns and superior patient comfort (e.g., Nec-Loc, Jerome Medical, Moorestown, NJ) be used for long-term application.

One final complication should be mentioned. A patient who, for whatever reason, actively resists placement of a cervical collar or other splint should not be forced to wear it (Fig. 46-17). Postictal and intoxicated patients may present such a dilemma. Immobilization of a combative patient cannot be accomplished without considerable muscular exertion, not only by rescuers but also by the patient. If fractures do exist, it is possible that struggling can cause further damage. If the patient permits manual stabilization, this should be used as an alternative. Sedation may be used judiciously to enhance compliance.

Figure 46-17 This seizure patient was initially postictal and combative and did not allow prehospital cervical spine immobilization. Although this is a dilemma for all involved, it is best to avoid forcing such immobilization (see Box 46-1). Sedation may be an alternative if injury is suspected and immobilization is deemed clinically necessary. Despite a now clear mental status and no neck pain (and National Emergency X-radiology Utilization Study rules negative), an unneeded collar was subsequently applied in the emergency department, to the annoyance of the patient, who then became very agitated and tried to leave. Note that the patient is now physically restrained and is incorrectly still upright.

Thoracolumbar Immobilization

In general, complications are more likely to occur from failure to immobilize spinal injuries before movement than from the technique of immobilization. When complications do arise, they may be related to improper choice or use of equipment or prolonged immobilization.

Victims are generally strapped in place on a spine board to prevent sliding during transport. If too few straps are used or if the straps are loosely applied, motion during transport can occur. Moreover, even when applied correctly, spinal immobilization on a hard board may be extremely uncomfortable for patients and may induce pressure-related tissue damage. In one study, 100% of healthy volunteers reported significant pain after only 30 minutes on a long spine board.³⁶ Occipital headaches, as well as mandibular, lumbar, and sacral pain, developed in these subjects. Other studies have demonstrated elevated tissue interface pressure in patients on spine boards without air mattress padding.^38,58,59 These studies underscore the need to use adequate padding and remove patients from the board as soon as possible.

Excessive strapping can interfere with respiratory function in both children ⁶⁰ and adults.^61–63 In healthy children 6 to 15 years old, forced vital capacity (FVC) has been shown to decrease from 4% to 59% during spinal immobilization.⁶⁰ Totten and Sugarman⁶³ evaluated the effect of two spinal immobilization methods (wooden backboard and vacuum mattress) on eight respiratory function measurements in healthy volunteers. In comparing baselines for each method, six of the eight measures (FVC, FVC%, forced expiratory volume in 1 second [FEV₁], FEV₁%, peak expiratory flow [PEF], and forced expiratory flow [FEF_25-75%]) were reduced an average of 15%. Although this may not be a problem in healthy volunteers, the effects on patients with chest trauma or preexisting respiratory disease may be significant.⁶³

Patients immobilized on a backboard are also at risk for aspiration if they vomit. If this does occur, the patient and board should be logrolled as a unit to the side. Although this procedure may be associated with some spinal movement, airway protection takes precedent.

Conclusion

Even though spinal immobilization has not been shown to decrease the likelihood of spinal injury and may actually increase morbidity because of complications, it remains a mainstay of prehospital trauma treatment. Prehospital providers will continue its practice until further evidence leads to a widespread paradigm shift and modification of trauma protocols. In the meantime, emergency medicine practitioners should know when its continued use is indicated, recognize properly and improperly applied devices, and minimize unnecessary immobilization time.

Extremity Immobilization

Upper Extremity

Rigid Splints: Rigid and semirigid splints are the mainstays of EMS fracture care (Fig. 46-18A-C). These splints are made of many different material, including cardboard, plastic, aluminum, wire, and wood. They are fastened to the injured extremity with tape, gauze, cravats, or Velcro straps. Rigid splints are generally nonflexible (some commercially available splints may have some flexibility in their design) and, when applied properly, immobilize the limb in a rigid fashion to maintain stability. Although most commercial rigid splints are prepadded, many will still benefit from additional soft padding to cushion the splint and increase comfort. This is particularly true over bony prominences. When applying rigid splints, leave the fingertips exposed so that the distal circulation can be continuously monitored.

Figure 46-18 Upper extremity splints. A-C, Padded rigid splints. D, SAM Splint. E, Evac-U-Splint vacuum splint. F, Soft towel splint. (A pillow can be used in a similar manner.) G, Sling and swath. (D, Courtesy of SAM Medical Products, Portland, OR; E, courtesy of Hartwell Medical, Carlsbad, CA.)

Cardboard splints are excellent for long-bone fractures in the upper part of the arm. They can be formed into many shapes and are easy to apply, inexpensive, lightweight, radiolucent, and compatible with magnetic resonance imaging. Splints made from wax-impregnated cardboard are also water resistant. Plastic, aluminum, wire, and wood splints, though less malleable, are also good choices. An inexpensive aluminum splint that is popular with emergency care providers and can be found in many wilderness medical kits is the SAM Splint (Sam Medical Products, Portland, OR) (see Fig. 46-18D). The SAM Splint is built from a thin core of soft aluminum alloy sandwiched between two layers of closed-cell foam. The SAM Splint is extremely pliable. Bent into any of three simple curves, it is extremely strong and provides support for any fractured or injured extremity. In addition, it is water resistant, lightweight, radiolucent, reusable, and not affected by extreme temperatures or altitudes. These characteristics make it an ideal tool for emergency care providers and outdoor enthusiasts.

Vacuum splints (see Fig. 46-18E) are a special type of rigid splint in which the air is evacuated from a closed bag containing tiny foam beads. This compresses the contents into a solid mass and results in a rigid splint. Injuries can be encased and immobilized in the position in which they are found, thereby reducing patient discomfort. Flexibility of the splint before removal of the air allows molding of the splint to conform to the patient’s position. Vacuum splints are radiolucent and do not apply external pressure, thus ensuring maximum circulation to the injured extremity.

Soft Splints: Soft splints include air splints, pillows, slings, and swaths. Depending on the type of injury being treated, immobilization with pillows, slings, or swaths alone may be inadequate because they allow significant flexibility and motion. Therefore, when treating fractures and dislocations, these splints are most effective when used with some form of a rigid device. However, even when used alone, pillows, slings, or swaths provide cushioning and some limitation of motion that may be adequate for less severe injuries such as sprains and contusions.

Air splints are soft splints that become rigid when inflated. Besides providing immobilization, they help compress the underlying soft tissue to reduce local hemorrhage. These devices are sensitive to differences in atmospheric pressure and temperature. Therefore, constantly monitor their inflation to ensure that the underlying tissue is not being subjected to pressure-induced ischemia and the development of a compartment syndrome. One study suggested a maximum splint pressure of 15 mm Hg to reduce the risk for ischemia.⁶⁷ With long ambulance transport times, deflate the splint for 5 minutes every 1.5 hours.⁶⁸

Disadvantages include an inability (with most air splints) to continuously monitor pulses once the air splint is in place and susceptibility of the air splint chambers to puncture. Air splints are designed to conform to a specific shape when inflated and should not be used on angulated fractures. In addition to being radiolucent, some types can be inflated with a refrigerant to provide concurrent cooling.

Pillow splints (see Fig. 46-18F) can be fashioned from any soft bulky material and are excellent choices for hand or wrist injuries. These splints are extremely comfortable and can be applied easily.

Slings and swaths are generally used in combination with a rigid or a soft splint. When used alone, they can effectively immobilize injuries to the shoulder, clavicle, or humerus (see Fig. 46-18G).

Procedures

To properly apply a splint to an injured extremity, several guidelines should be followed. Communication is important to ensure that the patient understands what is being done at all times. When possible, administer an appropriate analgesic to make splint application less painful. Remove any unnecessary clothing to adequately visualize the injured extremity. Stabilize the fracture site manually to help limit unnecessary movement and prevent further injury. Check the patient’s neurovascular status (i.e., pulse, motor, and sensation) before and after the application of a splint. For a severely angulated extremity with neurovascular compromise, reduce the deformity with gentle longitudinal traction (but not exceeding 10 lb of pressure) before splinting. Make only one attempt at fracture reduction. If resistance or pain is encountered, splint the extremity in the position found. Cover open wounds with a dry sterile dressing before applying the splint. Apply the splint (Table 46-1) by using the orthopedic principle of immobilizing the joint above and below a suspected fracture site. Cool and elevate the injured area to help reduce local swelling and pain. Once the splint has been applied, assess distal neurovascular status frequently. Any deterioration requires immediate evaluation of the splint to determine whether excessive pressure is being applied. In addition, frequently assess and treat pain.

TABLE 46-1

Management of Specific Upper Extremity Orthopedic Injuries

SITE	SUGGESTED IMMOBILIZATION TECHNIQUES
Clavicle	Sling and swath
Shoulder	Sling and swath as it lies
Humerus	Cardboard or vacuum splint with a sling and swath
Elbow	Cardboard or vacuum splint as it lies
Forearm	Cardboard, malleable metal, air, or vacuum splint with a sling and swath
Wrist	Pillow, cardboard, malleable metal, or vacuum splint applied in the position found
Hand	Pillow, cardboard, or malleable metal splint in the position of function
Finger	Tongue depressor or small malleable metal splint

Rigid Splints: To apply a rigid splint, have an assistant provide support and gentle traction above and below the injury. Apply the splint on the side of the extremity away from any open wounds. The splint should be large enough to immobilize the joint above and below a suspected fracture or the bone above and below a dislocation and be well padded to reduce the risk for pressure necrosis. Secure the splint to the extremity with gauze, tape, cravats, or Velcro straps (see Fig. 46-18A-C).

Apply vacuum splints in much the same manner as other rigid splints. While an assistant stabilizes the injured site and applies traction, wrap the splint around the extremity and secure it in place with the attached straps. Evacuate the air from the splint with a hand pump until the splint becomes rigid.

Soft Splints: The application procedure for an air splint depends on whether the splint is equipped with a zipper. If the splint does not have a zipper, first place the splint over the rescuer’s arm until the bottom edge lies above the wrist. Use this hand to grasp the hand of the patient’s injured extremity and use the free hand to provide support and gentle traction above the injury (Fig. 46-19A). An assistant then slides the splint onto the patient’s arm (see Fig. 46-19B). Smooth out any wrinkles and inflate the splint until finger pressure makes a slight dent (see Fig. 46-19C). Open a zippered air splint and place it around the injured area. Close the zipper and inflate the splint as described previously. With air splints that completely enclose the hand, continuously assess the distal circulation by checking fingertip color, temperature, and capillary refill.

Figure 46-19 Air splint application.

Apply pillow splints by encasing the injury in the pillow and securing it with tape, cravats, or gauze (see Fig. 46-18F). If possible, keep the nail beds exposed to allow frequent neurovascular checks.

To apply a sling, have an assistant support the injured arm in a flexed position across the patient’s chest (Fig. 46-20). Place the long edge of the triangular bandage lengthwise along the patient’s side opposite the injury with its tip over the uninjured shoulder. Bring the other tip over the injured shoulder to enclose the arm in the sling. Adjust the sling so that the arm rests comfortably with the hand higher than the elbow. Tie the ends of the sling together at the side of the neck and pad the knot for comfort. Finally, wrap the point of the sling at the elbow around the front of the forearm and pin. With the sling properly applied, rest the patient’s arm comfortably against the chest with the fingertips exposed.

Figure 46-20 Sling application. Note that the wrist is supported by the sling (arrow) since the tendency is to flex the wrist with any upper extremity injury.

To apply a swath, place a cravat of sufficient length under the uninjured arm and over the injured arm at the level of the midhumerus. Tie the ends circumferentially around the thorax so that the injured extremity is secured snugly to the chest (see Fig. 46-18G). In adults, two cravats may have to be tied together in an end-to-end fashion to produce a swath of sufficient length.

Complications

Potential complications of upper extremity splinting include pressure necrosis, conversion of a closed injury to an open one, and loss of neurovascular function. With the use of air splints, there is the additional risk of pressure-induced tissue ischemia and compartment syndrome.⁶⁷

Conclusion

Injuries to the upper extremities, though not life-threatening, may be limb-threatening and can have significant immediate or long-term effects. Maintain a high index of suspicion for underlying neurovascular injury; check neurovascular status before and after applying a splint and frequently during transport. When possible, administration of appropriate analgesia will be greatly appreciated by the patient.

Lower Extremity

Background

Injuries to the lower extremities, including sprains, fractures, and dislocations, are also commonly encountered by prehospital care providers. As with upper extremity injuries, application of a splint is an essential part of the prehospital management of lower extremity injuries. Many of the principles, techniques, and complications discussed for upper extremity splinting also apply to injuries to the lower extremity; the SAM Splint (see Fig. 46-18D) and pillow splint (Fig. 46-18F) are just two examples (Fig. 46-21; also see Fig. 46-18). Table 46-2 provides recommendations for immobilizing a variety of lower extremity injuries. One fundamental difference between splinting upper and lower extremity injuries is use of a traction splint in the management of femoral fractures. The remainder of this section focuses on the use of traction splints.

TABLE 46-2

Management of Specific Lower Extremity Orthopedic Injuries

SITE	SUGGESTED IMMOBILIZATION TECHNIQUES
Hip	Traction splint and long backboard or secure the injured leg to the uninjured leg Long backboard with the limb supported by pillows
Femur	Traction splint or pneumatic antishock garment
Knee	Cardboard or vacuum splint in the position found
Tibia/fibula	Cardboard, air, or vacuum splint
Ankle	Pillow or air splint
Foot	Pillow or air splint
Toe	Tape to the adjacent toe

Figure 46-21 Prefabricated padded leg splint. Similar to the arm splints described earlier, many prefabricated leg splints are commercially available. Their application and use mirror the general principles of splinting described in Figure 46-18.

The use of traction and countertraction for alignment and reduction of fractures dates from the time of Hippocrates.⁶⁹ In the late 1800s, Sir Hugh Owen Thomas developed the first full-ring traction splint for the definitive management of fractured femurs.^64,69 However, because the Thomas full-ring splint was difficult to apply on the battlefield, it was later modified by his nephew, Sir Robert Jones, and other surgeons to a half-ring design that made it easier to apply during battle. During World War I, the modified splint was credited with reducing the mortality rate associated with fractured femurs from 80% to 15%.⁶⁹ Since then, several additional modifications that carry the name of their inventors (e.g., Glenn Hare, Joseph Sager, Allen Klippel) have furthered the development of lower extremity traction splints. Today, traction splints are a nearly universal piece of equipment found on most ambulances, and their application is an integral part of the prehospital care provider’s skill set. The main purpose of the traction splint is to immobilize a fractured femur.^70,71

In the setting of a fractured femur, muscle spasm and overlap of fragments may cause the thigh to lose its cylindrical shape and adopt a more spherical appearance (Fig. 46-22).⁶⁹ The resultant decreased tissue pressure and increased volume may allow 1 to 2 L of blood to accumulate at the fracture site. Traction splints are designed to align fracture segments and restore the cylindrical shape of the thigh (Fig. 46-23). This in turn increases tissue pressure, decreases the potential space for blood loss, and inhibits further hemorrhage. In addition, traction splints help reduce pain, prevent further damage to neurovascular structures, and lower the incidence of fat embolism.^70,71

Figure 46-22 Femur fracture. Anteroposterior and lateral views of the right femur demonstrate a displaced, angulated, and foreshortened femoral fracture. Such injuries may result in substantial hemorrhage into the thigh, even to the point of hemorrhagic shock.

Figure 46-23 Use of a traction splint helps restore femoral fractures to a more natural anatomic alignment, which may reduce hemorrhage, pain, and damage to surrounding neurovascular structures.