Epidemiology

Spinal cord injury typically occurs in males at the peak of their productive lives. The incidence of traumatic SCI is approximately 11,000 new cases each year in the United States,¹ with a prevalence of 191,000. The prevalence of SCI patients is increasing steadily owing to improved survival in both the acute and chronic stages of the disease. The amount spent on the treatment of spinal cord injuries in the United States is approximately 5.6 billion dollars each year and rising annually.² The cost of caring for the individual spinal cord–injured patient is directly related to the injury level of the spinal cord and to the patient’s age, with the highest costs associated with older quadriplegic patients who are dependent on a ventilator.²

Etiology

Most spinal injuries result from high-speed motor vehicle accidents (Figure 39-1). Falls and work-related injuries are other important contributors. Spinal cord injury that is due to violence is on a dramatic rise secondary to increased incidence of assaults. These injuries include both blunt and penetrating injuries, such as gun and knife wounds. Sports-related injuries, which include football, horseback riding, and hockey injuries, are relatively rare but have received recent media attention.^3–4 Finally, recreational injuries from jet skis, snowmobiles, snow skiing, snowboarding, and parachuting, to name but a few, appear to be on the rise as “extreme sports” become more prevalent.

Figure 39-1 A, Sagittal T2-weighted MRI demonstrates a C6-C7 fracture-dislocation with severe cord compression in a patient who presented with complete C6 quadriplegia-ASIA. B, Patient was treated surgically to realign the spine and gained significant root recovery without any recovery of hand or lower extremity function.

Initial Management

Suspected SCI alters the basics of the “ABCs” of resuscitation in several important ways. With respect to airway management, suspected SCI dictates in-line immobilization of the spine at all times, so hyperextension of the neck is contraindicated. A jaw thrust must be used to open the airway, and required intubation must be done with the head/neck in a neutral position. This is an important point to remember because patients with a high SCI will have diminished or absent respiratory capacity and frequently require emergent intubation.

Aggressive resuscitation of SCI patients proceeds as with all trauma patients. As indicated earlier, however, upper SCI may be associated with neurogenic shock, requiring large-volume fluid replacement. Although pressors are likely to be required in the setting of neurogenic shock, field management is commonly limited to fluid resuscitation. High incidence of associated head injury often requires use of colloid solutions in addition to normal saline/lactated Ringer’s solution in an effort to adequately resuscitate the patient while minimizing exacerbation of cerebral edema.

Immobilization and Diagnostic Evaluation

Rigid immobilization is indicated if there is any doubt about the presence of SCI. Presence of altered mental status in any way dictates the use of “spinal cord precautions.” These include use of in-line immobilization, maintenance of neutral position, cervical immobilization with a rigid collar, and use of backboards for transport.

After initial resuscitative efforts, diagnostic studies are undertaken. Fine-cut helical computed tomography (CT) scan with coronal and sagittal reconstructions have supplanted plain radiographs in most trauma centers as an initial evaluation in detecting spine fractures. Additional spine studies may be obtained after the patient has been stabilized and more emergent diagnostic studies have been undertaken. During this time, rigid cervical collar and backboard immobilization must be continued.

Further diagnostic studies will be dictated by the findings of the initial and secondary surveys as well as findings of initial diagnostic studies. Several points are important to keep in mind. First, important information can be obtained from studies performed for other reasons. For example, routine chest and abdominal radiographs may provide important information regarding the presence of significant thoracic/lumbar spine injury. Although these do not replace subsequent “formal” spine studies, they are often obtained as part of the routine trauma workup and provide early clues to the presence of spine trauma and may help prioritize subsequent imaging studies (Figure 39-2). Radiographs and particularly the CT are the most sensitive tools in detecting a fracture of the spine, but occasionally it is difficult to clear the spine—even in the absence of a fracture—because an unstable ligamentous injury without fracture may exist.

Figure 39-2 This 45-year-old man sustained (A) an L4 fracture-dislocation and presented with a dense footdrop. He underwent (B) anteroposterior reconstruction with instrumentation.

Patients with a suspected spinal column injury who are unconscious, uncooperative, or intoxicated or who have associated traumatic injuries that distract from their assessment will often require further radiographic study of the cervical spine before the discontinuation of cervical spine immobilization. Several options exist and include (1) maintenance of the collar and/or spine precautions until the patient becomes coherent and responsive, (2) dynamic imaging of the spine with physician monitoring, and (3) magnetic resonance imaging (MRI) of the spine to rule out a purely ligamentous injury. Of the three options, we frequently use MRI to clear the spine because a completely negative MR image in the setting of trauma indicates that there is no instability of the cervical spine (Figure 39-3). Malalignment and evidence of spine trauma on these imaging studies frequently determines subsequent management and diagnostic decision making. Cervical subluxations often require the use of traction and/or manual reduction of the fracture-dislocation. Diazepam (Valium) or lorazepam (Ativan), along with careful neurologic monitoring, often in the intensive care unit (ICU) setting, is required because application of traction can realign the spine but can also result in neurologic deterioration.

Figure 39-3 A, Admission lateral radiograph of a 31-year-old man who was “cleared” in the emergency department after cervical spine series and CT failed to demonstrate a fracture. Patient had a Glasgow Coma Scale score of 11 on admission and significant facial fractures. B, He presented 1 year post admission with increasing neck pain and was diagnosed with a severe cervical kyphotic deformity with bilateral perched facets at C5-C6. MRI (gradient-echo sequence) done on admission in this obtunded patient would have easily demonstrated the posterior ligamentous injury between the C5 and C6 spinous process, which is relatively subtle on the admission lateral cervical spine radiograph seen in A.

Pediatric Spinal Cord Injury

Pediatric spine trauma is relatively uncommon, representing approximately 5% of all spinal cord injuries.⁵ For a specific discussion of pediatric SCI, please see Chapter 210. In addition, guidelines have been published on this topic.⁶

Pharmacotherapy

The concepts of primary and secondary SCI are important principles in understanding the pathophysiology and the role of pharmacotherapeutic agents in emergent treatment. The primary injury mechanism results from a mechanical insult that occurs at the time of impact and includes acute compression, impaction, distraction, laceration, and shear.⁷ Secondary injuries occur after the initial injury and account for some of the progressive pathologic changes associated with SCI.⁷ A number of drugs have been tested in the laboratory, but only a few of these agents have progressed to clinical trials to evaluate their efficacy. Five randomized controlled trials of pharmacotherapy for acute SCI have been conducted, focusing on the therapeutic effect of either corticosteroids or gangliosides.

Hypothermia

Two recent studies were published on the safety and feasibility of mild to moderate intravascular cooling for SCI. Levi et al. reported on a series of 14 patients with American Spinal Injury Association (ASIA) classification A complete cervical cord injuries who underwent a protocol to achieve temperatures of 33.5°C via a closed-loop delivery system. Researchers found good correlation between intravascular and intrathecal cerebrospinal fluid temperature.²⁵ Average time between inductions of hypothermia was 9.17 ± 2.24 hours (mean ± SEM); time to target temperature was 2.72 ± 0.42 hours; duration of cooling at target was 47.6 ± 3.1 hours; and average total length of time of cooling was 93.6 ± 4 hours. A subsequent paper summarized the complications and neurologic outcomes seen in the SCI patients treated with hypothermia and compared them to age- and injury-matched controls. The hypothermia group ASIA conversion rate to a higher grade was approximately 42%, with a similar frequency of complications to institutional controls.²⁶ This pilot study suggested that systemic intravascular cooling can be accomplished with minimal variations in temperature and few adverse events, and may pave the way for larger multicenter SCI trials to test the efficacy of mild to moderate hypothermia in SCI.²⁷

Intensive Care Unit Management

Spinal cord injury is associated with profound effects on all vital systemic functions. Through primarily class III medical evidence, numerous reports indicate lower morbidity and mortality rates in patients with SCI managed with ICU monitoring and aggressive medical management of these changes.^28–36 At the least, these studies taken together indicate that a systematic approach must be taken to evaluate and treat each of the potential complications. Early and late complications will be seen, and the degree of involvement of each system is usually correlated with the level and severity of injury.