Introduction
Spinal cord injury (SCI) is defined as an acute traumatic lesion of the neural elements of spinal canal, including spinal cord and cauda equina, that results in temporary or permanent sensory deficit, motor deficit, or bowel or bladder dysfunction.Reference Marr and Coronado 1 , Reference O'Connor 2 Spinal cord injury can occur at different levels, including cervical, thoracolumbar, and lumbosacral.Reference Sekhon and Fehlings 3 The severity of injury is classified as incomplete or complete, and the symptoms may vary from pain to complete paralysis.Reference O'Connor 2 , Reference Del Rossi, Heffernan, Horodyski and Rechtine 4 Spinal cord injuries can be devastating for both patients and their families. Severe injuries can adversely affect the patient's independence, quality of life, and socioeconomic circumstances.Reference Pickett, Campos-Benitez, Keller and Duggal 5 , Reference Kattail, Furlan and Fehlings 6 Prehospital care is considered integral to enhancing patients’ recovery and quality of life after such an injury.Reference Tator 7 , Reference Celani, Spizzichino, Ricci, Zampolini, Franceschini and Retrospective Study Group on 8
Generally, prehospital spinal immobilization is the accepted standard of care.Reference Del Rossi, Heffernan, Horodyski and Rechtine 4 , Reference Bulger and Maier 9 , Reference Kwan, Bunn and Roberts 10 This practice includes cervical and full body immobilization in cases of suspected cervical spine or SCI patients.Reference Vanderlan, Tew and Seguin 11 Spinal immobilization is based on the premise that minimizing the movement of the spineReference Miglietta, Levins and Robb 12 , Reference Vickery 13 will reduce risk of secondary injuriesReference Vickery 13 , Reference Geisler, Coleman, Grieco, Poonian and Sygen Study 14 and facilitate extrication as well as transport.Reference Vickery 13
The purpose of this paper is to review the literature on the reported causes of traumatic SCIs, patient demographics, benefits and harm of prehospital spinal immobilization, as well as the evidence on the relationship between prehospital spinal immobilization and neurological outcomes.
Methodology
The search was conducted using the online databases Ovid Medline (Ovid Technologies, New York, New York USA), PubMed (National Center for Biotechnology Information, Bethesda, Maryland USA), CINAHL (EBSCO Information Services, Ipswich, Massachusetts USA), and the Cochrane Library (Cochrane Collaboration, Oxford UK) from January 2000 through November 2012. The search included combinations of the keywords in the prehospital search filterReference Smith, Archer and Burgess 15 with medical subject headings (MeSH) terms and keywords relevant to the epidemiology and outcomes of SCI. The titles of the articles were initially screened for relevancy, and the abstracts were reviewed where relevancy was not clear from the title. The first author manually searched the reference lists of the included articles to identify relevant literature that may have been overlooked in the search.
Results and Discussion
Epidemiology
Incidence and Mortality Rates—Chiu et al have compared the reported incidence rates of traumatic SCI in developed and developing countries. In developed countries, incidence rates ranged from 13.7 per 1 million in Finland to 52.2 per 1 million in Alberta, Canada. Among the developing countries, incidence rates ranged from 12.7 per 1 million in Turkey to 29.7 per 1 million in Russia. This variation between developed and developing countries may be influenced by underreporting and/or under diagnosis of cases of SCI, or increased numbers of patients who died on scene or during transport because of inappropriate handling or transportation.Reference Chiu, Lin, Lam, Chu, Chiang and Tsai 16
The reported mortality rates range from 3.1 per 1 million people in China to 17.5 per 1 million people in Nigeria.Reference Chiu, Lin, Lam, Chu, Chiang and Tsai 16 The variation in these rates may relate to different reporting and sampling methods; for example, in China, the reported deaths included those who stayed in the hospital for acute care only. A low mortality rate of 6.6% has been reported in Taiwan, but this report excluded patients who died prior reaching the hospital.Reference Chiu, Lin, Lam, Chu, Chiang and Tsai 16
Etiologies—The major cause of traumatic SCIs has been documented to be transport related, mainly motor vehicle collisions (MVCs),Reference O'Connor 2 , Reference Sekhon and Fehlings 3 , Reference Pickett, Campos-Benitez, Keller and Duggal 5 , Reference Akmal, Trivedi and Sutcliffe 17 , Reference Burton, Harmon, Dunn and Bradshaw 18 although other studies in several countries have found falls to be the leading cause.Reference Kattail, Furlan and Fehlings 6 , Reference Celani, Spizzichino, Ricci, Zampolini, Franceschini and Retrospective Study Group on 8 , Reference Pickett, Simpson, Walker and Brison 19 Other etiologies include water-related injuries,Reference Geisler, Coleman, Grieco, Poonian and Sygen Study 14 violence,Reference Sekhon and Fehlings 3 gunshot wounds,Reference Geisler, Coleman, Grieco, Poonian and Sygen Study 14 work accidents,Reference Sekhon and Fehlings 3 and sport-related injuries.Reference Sekhon and Fehlings 3
Patient Demographics—Males have a higher incidence of SCI than females.Reference Pickett, Campos-Benitez, Keller and Duggal 5 , Reference Kattail, Furlan and Fehlings 6 The male to female ratio was reported to range from 1.6:1 in an Irish studyReference Roche, Sloane and McCabe 20 to as high as 6:1 in a study in New South Wales, Australia.Reference Middleton, Davies, Anand, Reinten-Reynolds, Marial and Middleton 21
Cervical Injuries—Cervical SCIs contribute to approximately 55% of all SCIsReference Pickett, Simpson, Walker and Brison 19 ranging from 41% to 75% in developed countries, and from 4.8% to 47.2% in developing countries.Reference Chiu, Lin, Lam, Chu, Chiang and Tsai 16 This wide range, once again, may be explained by underreporting of cases of SCIs in the developing countries, increased numbers of patients who died prior to reaching hospital, or as a result of improper management or triage.Reference Chiu, Lin, Lam, Chu, Chiang and Tsai 16
Prehospital Care
Prehospital Spinal Immobilization—Full spinal immobilization includes immobilizing the head, neck, and body in neutral alignment.Reference Vickery 13 This is achieved through the use of appropriate transfer techniques, cervical spine collars (c-collars),Reference Miglietta, Levins and Robb 12 , Reference Kang and Lehman 22 lateral support,Reference Kang and Lehman 22 and spine boards and straps.Reference Miglietta, Levins and Robb 12 , Reference Kang and Lehman 22 Other devices used include a scoop stretcher with a rigid cervical collar and straps,Reference Krell, McCoy, Sparto, Fisher, Stoy and Hostler 23 a vacuum mattress in combination with a rigid cervical collar,Reference Bernhard, Gries, Kremer and Bottiger 24 and a Kendrick Extrication Device (KED, also known as a short board) to assist with extrication following a motor vehicle crash or other confined space rescue.Reference Bernhard, Gries, Kremer and Bottiger 24
Despite the lack of evidence, prehospital spinal immobilization is a widely-accepted practice for patients with suspected SCIs.Reference Del Rossi, Heffernan, Horodyski and Rechtine 4 , Reference Bulger and Maier 9 , Reference Kwan, Bunn and Roberts 10 It aims to minimize further movement of the spine,Reference Miglietta, Levins and Robb 12 , Reference Vickery 13 reduce the risk of secondary injury,Reference Vickery 13 , Reference Geisler, Coleman, Grieco, Poonian and Sygen Study 14 and facilitate extrication as well as transport.Reference Vickery 13 However, it has several disadvantages, including increased risk of respiratory compromise,Reference Vickery 13 , Reference Stroh and Braude 25 , Reference Hankins, Rivera-Rivera and Ornato 26 back and neck pain,Reference Kang and Lehman 22 , Reference Stroh and Braude 25 – Reference Domeier, Frederiksen and Welch 28 risk of pressure sores,Reference Jonathan and Julian 29 and raised intracranial pressure associated with cervical collar application.Reference Jonathan and Julian 29 – Reference Deasy and Cameron 31 Immobilization is also time consuming and expensive.Reference Stroh and Braude 25 It also does not appear to prevent neurologic injury progression.Reference Vanderlan, Tew and Seguin 11 , Reference Hauswald, Ong, Tandberg and Omar 32 Moreover, it may increase the risk of dropping the patientReference Stroh and Braude 25 , Reference Hankins, Rivera-Rivera and Ornato 26 or injuring Emergency Medical Services (EMS) personnel carrying the patient, especially when traversing unstable paths.Reference Hankins, Rivera-Rivera and Ornato 26 Huswald argued that the damage to the spinal cord is primarily due to the initial impact, and that a subsequence movement, without a significant force, is very unlikely to exacerbate that damage.Reference Hauswald, Ong, Tandberg and Omar 32
A 2001 Cochrane systematic review reported a lack of randomized controlled trials that compare different spinal immobilization techniques or evaluate the effects of spinal immobilization on mortality, neurological injury, and spinal stability in trauma patients. However, the search strategy identified 17 randomized controlled trials that compared different spinal immobilization strategies in healthy volunteers. The authors recommended large prospective studies to validate the decision criteria in patients with high risk of SCI, as well as randomized controlled trials to compare different immobilization techniques. This systematic review was updated in 2009, and did not identify any new randomized controlled trials.Reference Kwan, Bunn and Roberts 10
Prehospital Immobilization in Blunt and Penetrating Trauma—Despite limited large-scale interventional studies examining the utility of spinal cord immobilization, there is a general acceptance by EMS providers of immobilization as the standard of care following blunt trauma. However, there is debate on its indications, risks, and benefits in penetrating trauma to the neck.Reference Barkana, Stein and Scope 33
Penetrating Trauma—It has been reported that penetrating trauma is very unlikely to cause instability, and therefore, immobilization may be not necessary. It also has been suggested that in the absence of instability in penetrating trauma, immobilization will be of a minimal benefit for the patient,Reference Barkana, Stein and Scope 33 , Reference Haut, Kalish and Efron 34 may be associated with higher mortality,Reference Barkana, Stein and Scope 33 , Reference Haut, Kalish and Efron 34 and may increase the risk of deterioration.Reference Vanderlan, Tew and Seguin 11 Furthermore, application of c-collars in penetrating trauma may hide underlying injuries,Reference Barkana, Stein and Scope 33 , Reference Ramasamy, Midwinter, Mahoney and Clasper 35 complicate the assessment of tracheal deviation,Reference Stuke, Pons, Guy, Chapleau, Butler and McSwain 36 increase the risk of hematoma development or expansion,Reference Stuke, Pons, Guy, Chapleau, Butler and McSwain 36 increase intubation difficulty, and put the patient at risk of prolonged hypoxia.Reference Barkana, Stein and Scope 33
Trauma Life Support Guidelines—Advanced Trauma Life Support (ATLS) guidelines recommend cervical spine immobilization in cases of suspected cervical or SCI until excluded by radiology. Although these guidelines have been developed to protect the unstable cervical spinal column,Reference Vanderlan, Tew and Seguin 11 the guidelines have not been shown to benefit patients with penetrating injury.Reference Vanderlan, Tew and Seguin 11 , Reference Ramasamy, Midwinter, Mahoney and Clasper 35 Therefore, the guidelines should distinguish between spinal immobilization for blunt and penetrating trauma.
Prehospital Selective Spinal Immobilization—Prehospital selective immobilization protocols (also known as spinal clearance protocols) aim to identify trauma patients who are at very low risk of sustaining a SCI, and therefore could be transported without spinal immobilization.Reference Burton, Harmon, Dunn and Bradshaw 18 , Reference Vaillancourt, Charette, Kasaboski, Maloney, Wells and Stiell 37 Hoffman et al have validated five criteria (known as the Nexus criteria) where patients’ cervical spine can be cleared without imaging;Reference Hoffman, Mower, Wolfson, Todd and Zucker 38 these include:
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1. no midline cervical tenderness;
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2. no altered mental status;
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3. no evidence of intoxication;
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4. no painful distracting injuries; and
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5. no focal neurological deficits.
Another tool, the Canadian C-spine Rule (CCR), originally was designed to standardize the cervical clearance protocol in alert stable patients in Canadian emergency departments, where radiography is required in patients who fulfil the criteria.Reference Vaillancourt, Charette, Kasaboski, Maloney, Wells and Stiell 37
Vaillancourt et al undertook a prospective study designed to evaluate the safety of the application of the CCR by paramedics in prehospital settings. This study revealed that about 40% of trauma patients could be transported without c-spine immobilization. The study protocol included the following three CCR criteria:Reference Vaillancourt, Charette, Kasaboski, Maloney, Wells and Stiell 37
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1. High-risk patient, including age ≥65, dangerous mechanism of injury, or numbness or tingling in extremities. Positive findings mandated c-spine immobilization, whereas absence of these conditions leads to further assessment in criterion 2 (low risk).
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2. Low risk, including simple rear-end MVC, ambulatory any time at scene, no neck pain at scene when asked, or no pain during midline palpation. Presence of any these condition leads to further assessment in criterion 3.
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3. Patient ability to voluntarily rotate the neck 45 degrees left and right when requested. Inability to rotate the neck mandates spinal immobilization.
Some EMS, such as Ambulance Victoria in Australia, have developed a modified clearance criteria that combine Nexus and CCR in an attempt to increase the selective criteria's specificity and sensitivity. 39
The safety of the application of selective protocols has been questioned; however, Stroh et al and Armstrong et al have concluded that trained prehospital personnel can safely apply the selective guidelines and transport these patients without spinal immobilization,Reference Stroh and Braude 25 , Reference Armstrong, Simpson, Crouch and Deakin 40 but should do so with caution when managing patients at extreme ages.Reference Stroh and Braude 25 In addition, two prospective studies published in 2005 found that selective immobilization has safely decreased the application of spinal immobilization for 40% of trauma patients.Reference Burton, Harmon, Dunn and Bradshaw 18 , Reference Domeier, Frederiksen and Welch 28
Paramedics’ Role in Improving the Neurological Outcome
Paramedics play an important role in the patient's journey through effective prehospital management and through decreasing the time to spinal care units.
Prehospital Management—Improved recovery and reduced mortality are associated with effective resuscitation efforts,Reference Tator 7 , Reference Celani, Spizzichino, Ricci, Zampolini, Franceschini and Retrospective Study Group on 8 prevention of hypoxia,Reference Tator 7 and management of hypotension.Reference Tator 7 In an epidemiological study in Turkey, it was concluded that inadequately trained paramedics and the lack of first aid care led to higher death rates following traumatic SCI.Reference Karacan, Koyuncu and Pekel 41 Ahidjo et al also reported that a well-established prehospital system would decrease the mortality rate after spinal cord injuries in Nigeria.Reference Ahidjo, Olayinka, Ayokunle, Mustapha, Sulaiman and Gbolahan 42
Timing to Spinal Care Units and Neurological Recovery—Several experimental studies have concluded that better neurological outcomes and decreased complications are associated with early spinal decompression.Reference Belanger and Levi 27 , Reference Ahidjo, Olayinka, Ayokunle, Mustapha, Sulaiman and Gbolahan 42 – Reference Furlan, Noonan, Cadotte and Fehlings 44 Although there is no definite timeline for early transfer to surgery for isolated cervical SCIs, it is recommended that patients reach spinal units in 8-24 hours following injury,Reference Furlan, Noonan, Cadotte and Fehlings 44 assuming that the patient is hemodynamically stable.Reference Furlan, Noonan, Cadotte and Fehlings 44
It has been reported that shorter times to spinal units lead to shorter lengths of hospital stay,Reference Ploumis, Kolli, Patrick, Owens, Beris and Marino 43 decreased health care costs,Reference Ploumis, Kolli, Patrick, Owens, Beris and Marino 43 decreased in-hospital mortality rates,Reference Kattail, Furlan and Fehlings 6 and decreased dependence on mechanical ventilation.Reference Carreon and Dimar 45 A cohort study in New South Wales, Australia, found that patients who reached a spinal unit after 24 hours, compared to patients who reached the unit in less than 24 hours, were 2.5 times more likely to develop one or more secondary complications, including pulmonary embolism, deep vein thrombosis, and pressure ulcers.Reference Middleton, Davies, Anand, Reinten-Reynolds, Marial and Middleton 21
Paramedics may shorten the patient's journey by avoiding time delays through decreasing time spent on spinal immobilization at scene, giving priority to dealing with life-threatening emergencies. Moreover, shorter times to spinal units may be achieved by directly transferring the patient to spinal units. However, making such a decision should be based on specific criteria that are integrated into EMS's local clinical practice guidelines (CPGs) and scope of practice.
Limitations
This review has several potential limitations. First, studies published in languages other than English were excluded, and therefore, important studies relevant to topic may have been missed. Second, the search was limited to publications between January 2000 and November 2012. Finally, this review identified few reports of high-level, randomized, controlled trials; therefore, the review relies on the best available evidence identified in the literature. A strength of this review was that the search was supplemented by extensive manual reference list searches of the identified studies.
Conclusion and Recommendations
Spinal cord injury occurs throughout the world with an annual incidence ranging from 12.7 to 52.2 per 1 million, with causes including traffic crashes, falls, physical violence, and work, water, and sport-related injuries. Males have a higher incidence than females. Typically, prehospital immobilization is thought to be the best procedure to prevent neurological deterioration of patients with suspected SCIs; however, this is not based on solid scientific evidence and may be overly conservative unless applied to a discrete group of patients.
There is a paucity of evidence on the relationship between prehospital immobilization and its effect on patient neurological outcomes. However, applying selective immobilization criteria may safely reduce the number of prehospital immobilizations, thus reducing the time to spinal units, which is associated with better neurological outcomes.
This review supports the call for large prospective studies and randomized controlled trials to validate the use, benefits, and adverse effects of spinal immobilization on patients’ neurological outcomes.
