7 Prehospital Management of Spinal Injuries

Spinal cord injury (SCI) is a devastating event. In addition to the significant morbidity associated with SCI, there is a high mortality rate. The most common causes of mortality are respiratory and cardiac-related illnesses, accounting for 28 and 23% of deaths, respectively.1,2 Mortality is highest during the first year following injury and tends to decrease after the first year of survival. Young adults are most commonly afflicted with SCI. In the United States, the average age at injury was 28.7 years in the 1970s; however, the average age since the year 2000 has been 38.0 years, likely due to an aging population.³ By far the most common cause of SCI is motor vehicle accidents.^3–6 Other causes include pedestrian trauma, falls, penetrating wounds, sports injuries, and industrial and agricultural accidents.⁷ Recent data suggest that violence-related injuries have increased significantly, and violence is now the second most common cause after motor vehicle accidents. Cervical injuries represent 54% of all SCIs, and complete injuries are more common in the young (Fig. 7.1 ).⁸ Men are also four times more likely to suffer SCI than women (Table 7.1).

Fig. 7.1 Sagittal view of a reformatted computed tomography scan from a 15-year-old boy who sustained a C5-C6 fracture and a partial spinal cord injury in a diving accident.

Table 7.1 Spinal Cord Injury (SCI) Overview

In the individual with a spinal column injury without SCI or with partial SCI, the primary goal is to prevent development or progression of neurologic injury. In 1971, the emergency medical service (EMS) and the Spinal Cord Injury Model Systems (SCIMS) (Table 7.2) were established.⁹ In relation to spinal injury, EMS was designed to save lives and prevent further neurologic injury after the initial traumatic event. The goal of the federally sponsored SCIMS was to provide comprehensive care for patients with SCI. Five components comprise the SCIMS: prevention, prehospital care, acute care, rehabilitation, and follow-up. Prehospital care consists of emergency care, including evaluation, resuscitation, immobilization, retrieval (extrication), and transport.^9,10 Since the 1970s, there has been a decrease in the number of patients with spinal injuries who present to the emergency department with complete SCI. This decrease has been attributed to EMS and the principles of prehospital care.^7,11

Prehospital Management

In contrast to many European countries, emergency medical technician-ambulances (EMT-As), -paramedics (EMT-Ps), and, in certain instances, nurses, not physicians, provide the majority of prehospital medical care in the United States.10,12 EMT-As are trained in basic life support, immobilization, and extrication techniques, whereas EMT-Ps are skilled in advanced cardiac life support, including neurologic assessment, intubation, defibrillation, and administration of intravenous medication.⁷ These specially trained personnel are responsible for the five phases of prehospital management of SCI: (1) evaluation, (2) resuscitation, (3) immobilization, (4) extrication, and (5) transport.

Table 7.2 Spinal Cord Injury Model Systems (SCIMS)

In accordance with advanced trauma life support/advanced cardiac life support guidelines, the initial evaluation consists of a primary and then more thorough secondary survey.11 The primary survey assesses the “ABCDEs”: airway, breathing, circulation, disability (neurologic status), and exposure/environmental control.¹³ Although ordered in sequence of importance, the ABCDEs of trauma are typically assessed and treated simultaneously. Initial evaluation should confirm airway patency. In the patient with an obstructed airway, the establishment of an airway should be made while protecting the cervical spine. It is important to note that a conscious patient with SCI may or may not convey neck or back pain, and the unconscious patient is always assumed to have SCI. The assessment of breathing should include visual inspection, palpation, percussion, and auscultation of the chest for potential injuries (e.g., tension pneumothorax) that can impact ventilation. In evaluating the circulation, the level of consciousness, skin color, and pulse can assist in determining if the patient is hypovolemic. External bleeding is controlled with manual pressure. After the ABC of the ABCDEs have been assessed, a rapid neurologic assessment is performed (the D of ABCDE). Potential signs and symptoms of SCI include motor weakness/paralysis, sensory alterations, bowel/bladder incontinence, and tenderness to palpation along the spine.⁷ Deformities of the spine or abrasions/lacerations over the spine are also associated with SCI. Typically performed in the emergency department, exposure and environmental control (the E of ABCDE) entail completely undressing the patient for a more thorough examination and prevention of hypothermia¹³ (Table 7.3).

Table 7.3 Prehospital Management: Evaluation

Supplemental oxygen should be provided for any patient with suspected or confirmed SCI.10 In the conscious patient with a patent airway, a cut-off standard airway or a tongue blade wrapped in tape can be used as a “bite-stick” to prevent gagging.⁷ When an obstruction is present, establishment of a patent airway is critical. Any obvious foreign body should be removed. The chin lift and jaw thrust maneuver can help to open an airway, and a standard oral or nasopharyngeal airway can be used to maintain patency.^13,14 Because aggressive use of the chin lift and jaw thrust can exacerbate cervical instability, in-line stabilization should always be used in conjunction with these maneuvers. In addition, the nasopharyngeal airway appears to minimize the risk of exacerbating spinal instability as compared with the esophageal obturator or standard oral airway¹⁴ (Table 7.4).

Table 7.4 Prehospital Management: Resuscitation

If breathing is impaired with a patent airway, the patient should be intubated. Options include nasotracheal or orotracheal intubation. Nasotracheal intubation is absolutely contraindicated in the apneic patient and is relatively contraindicated in the patient with significant facial or skull-base fractures.13 Cadaveric studies have shown that nasotracheal intubation can cause less motion to the unstable subaxial cervical spine than orotracheal intubation.^14,15 For C1-C2 injuries, however, both nasotracheal and orotracheal techniques can result in narrowing of the spinal canal during intubation.¹⁶ As an alternative to blind nasotracheal intubation, which can be unreliable, studies have shown that orotracheal intubation with in-line cervical stabilization also limits motion to the unstable cervical spine and appears to be a safe alternative.^17,18

Cardiovascular stabilization not only is crucial to the overall health of the patient but also helps to prevent progression of neurologic injury.¹¹ Ischemia related to vascular alterations ranging from systemic hypotension to changes in local autoregulation and spinal cord blood flow have been postulated to be secondary mechanisms of SCI after the primary insult.¹⁹ In one clinical study, early volume resuscitation and elevation of the mean arterial blood pressure to greater than 85 mm Hg resulted in improvement in neurologic outcome after SCI.²⁰

In the prehospital setting, active hemorrhage should be treated with direct manual pressure and placement of a pressure dressing.^7,10 Intravenous (IV) access is usually obtained, but if rapid transport to a definitive care facility is available, prolonged delay for placement of an IV may not be warranted.¹¹ Typically, however, at least one IV is placed, and Ringer lactated solution is infused. Hypertonic saline has also been advocated as an alternative solution for volume resuscitation. However, a recent randomized trial of hypertonic saline versus Ringer lactate in patients with hypotension and traumatic brain injury found no difference in neurologic outcome.²¹ If indicated, measures including defibrillation and administration of cardiogenic medication are instituted to reestablish a normal cardiac rate and rhythm.

Patients with SCI may develop hemorrhagic shock. In those with injury above T4, neurogenic shock as well as hemorrhagic shock or a combination of the two may occur. Low blood pressure and body temperature are present in either hemorrhagic or neurogenic shock. The distinguishing characteristic is the heart rate, which is typically bradycardic with neurogenic shock and tachycardic and irregular with hemorrhagic shock. In neurogenic shock, the loss of the sympathetic nervous system causes decreased peripheral vascular tone and ultimately results in decreased cardiac return of blood from the periphery. Bradycardia occurs due to the lack of sympathetic tone to the heart, which results in increased parasympathetic activity. Placement of the patient in the Trendelenburg position is helpful in either type of shock.^7,11 Fluid resuscitation is used to treat hemorrhagic shock, but care must be taken in the patient with neurogenic shock because the problem is not volume loss. Excessive volume resuscitation in cases of neurogenic shock can cause congestive heart failure.¹¹ Although their efficacy is unclear in neurogenic shock, military antishock trousers may also be used.¹⁰ As a temporizing measure, 0.4 mg of atropine or dopamine may be administered in cases of neurogenic shock until the patient is transported for definitive care7 (Table 7.5).

Table 7.5 Spinal Cord Injury Shock

In the patient with a suspected or known SCI, the chief concern is to prevent further neurologic impairment from an unstable spine. Because as many as 20% of SCIs involve multiple levels, the entire spine requires immobilization.11 The best method for immobilization is the rigid, straight board in conjunction with a cervical stabilization device.⁷ The use of a semirigid cervical collar and bilateral sandbags joined with tape across the forehead attached to a board has been shown to be most effective in limiting motion compared with the soft collar, hard collar, extrication collar, semirigid (Philadelphia) collar, or bilateral sandbags and tape alone.²² Sandbags, however, are difficult and impractical to use. Therefore, the use of a rigid cervical collar with some type of bilateral bolstering device alongside the head and neck with the patient secured to a rigid board appears to be the best alternative.^13,23

Although it has become standard practice to immobilize all patients having a potential mechanism for SCI, immobilization in a cervical collar while strapped to a rigid board is not without adverse effects. Patient discomfort can be significant, and pressure sores can develop.²⁴ Pulmonary function can also be significantly restricted.^25,26 Selective spinal immobilization, as a consequence, has been advocated. Specifically, it has been proposed that immobilization should be reserved for those patients having a potential mechanism for SCI and with specific prehospital findings of altered mental status, neurologic deficit, spinal pain, intoxication, or distracting injury (e.g., extremity fracture).²⁷ In a retrospective study of 331 patients, each of these prehospital findings was associated with a significant cervical spinal injury.²⁸ A subsequent prospective study using these criteria found 94.9% sensitivity and 35.0% specificity for a finding of spinal injury. The positive predictive value was only 4.7%; however, the negative predictive value was 99.5%.²⁹ Although these findings suggest that a patient can be cleared clinically in the prehospital setting, further research is needed prior to universal acceptance of this practice (Table 7.6).

Table 7.6 Prehospital Management: Immobilization

Multiple factors can impact extrication, including accessibility to the patient, the local environment, and the condition of the patient.10 In general, EMT-As, EMT-Ps, and firefighters are specially trained in extrication techniques. Given the variability of the trauma scene, a commonsense approach has been advocated. Manual stabilization of the head and neck in the neutral position is recommended during extrication rather than use of a cervical collar. Movement of the patient to a neutral supine position rapidly and safely achieves the goal of a successful extrication7 (Table 7.7).

Table 7.7 Prehospital Management: Extrication

Once the SCI patient is stabilized, early transfer to a specialized SCI center results in decreased complications and better neurologic outcomes.9,30,31 Modes of transportation include ambulance, helicopter, or fixed wing aircraft. Selection of the most appropriate transport is dependent on the patient’s condition, availability, geography, and distance.^30,31

Conclusion

Prehospital management of SCI consists of five phases, each designed to prevent neurologic progression of SCI and optimize recovery. The recent decline in the number of emergency department patients presenting with complete SCI is likely the result of the establishment of EMS combined with implementation of the principles of prehospital management for SCI.

References

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