This is the sub-section of the Digital Research Library containing all material on the topic of spinal immobilization, C-spine injury, spinal clearance, acute care for traumatic spine injuries, and related matters.
Overview
The practice of prehospital spinal immobilization is based on physiological grounds. Since traumatic injury involving the spine often produces neurological sequelae (such as paralysis) by compromising the spinal cord, and initial hospital care for such injuries typically involves stabilization (via surgery, traction devices, or various forms of collars), it is hypothesized that some damage to the cord can be avoided if early spinal immobilization is provided by EMS.
It is agreed that many spinal cord injuries occur instantaneously at the time of initial trauma, in which case immobilization provides no benefit. It is also agreed that many spinal injuries (clinically insignificant fractures or dislocations) will never threaten the cord at any time. Prehospital immobilization is therefore meant to address middle cases: injuries which create instability in the spine that could damage the cord with the wrong movement, but have not yet done so (or at least not yet completely).
The practice has became widespread, yet has never been tested in any controlled trials. Now that it is considered standard of care, it has become nearly impossible to conduct controlled studies, since omitting immobilization is considered unethical. Only a single poorly-controlled study [Hauswald 1998] attempted to compare neurological outcomes between cohorts with and without immobilization; it showed a slight harm and no benefit associated with immobilization. There is an epidemiological argument that the incidence of complete spinal cord injuries (versus incomplete) decreased during the 1970s, when professional EMS — and hence C-spine care — became widespread in the US; some experts attribute this decrease to prehospital immobilization. Support for this claim is sparse.
Nearly all of the literature consists of observational studies (chart reviews, analyses of trauma registries, etc). Most focus on these areas:
Spinal clearance: Since spinal injury (particularly cervical spine injury) may be non-obvious, yet missing its presence is theoretically disastrous, most at-risk patients receive radiological examination in the ED. Several algorithms, particularly NEXUS and the Canadian C-spine Rule, have been developed establishing criteria to omit radiography in some low-risk patients; these have been repurposed for selective immobilization in the prehospital setting, since a patient who does not need radiography clearly does not need to be immobilized. [Search for NEXUS or Canadian.] A related body of research investigates the cause, and resulting morbidity, of missed diagnoses of spinal fracture. A sub-set of this examines the existence of “occult” C-spine fractures, which present without pain or neurological deficit; a number of case reports exist, but most have been questioned. [Search for missed, delayed, occult, or deterioration.]
Prevalence: It is useful for both prehospital and ED personnel to understand the likelihood that a given trauma patient may have a C-spine injury. A large body of work has therefore been done to determine the frequency of spinal injury among patients with head trauma, loss of consciousness, facial trauma, penetrating trauma, and various mechanisms of injury (search for desired terms). In most populations of adult blunt trauma patients, the incidence of non-trivial C-spine injury is reliably around 2%; this increases with injury severity or decreased GCS. A related group of studies examines complications of fracture other than cord damage [search for artery], and risk factors for fracture [search for ankylosing or DISH].
Effectiveness of stabilizing devices: Current standard of care for immobilization involves a combination of rigid cervical collar, blocks and tape or a head-bed device, and a hard longboard with straps. (Sandbags were often used in the past, but are now considered harmful.) Validating the effectiveness of these and other devices (scoop stretchers, vacuum splints, foam mattresses, KED, etc.) is the focus of a number of studies, often using cadavers, although some recent studies have used motion capture and live participants. As a rule, these studies are never done in vivo using true injuries. [Search for collar, extrication, board, or movement.]
Adverse effects of immobilization: Various studies, mostly small-scale trials, have demonstrated significant (although usually non-lethal) harmful effects from board-and-collar immobilization. These include pain and discomfort, development of pressure ulcers, pulmonary restriction, challenges to airway management, and most significantly, delay of transport for time-critical trauma patients. [Search for the desired terms.]
When considering research, it is important to understand that the endpoint for these studies is usually the presence of a radiologically-defined C-spine injury which experts feel could potentially damage the cord. Whether said injury has a non-trivial potential of damaging the cord prior to hospital arrival (i.e. the EMS phase) is usually not addressed. Although anecdotal reports of sudden neurological deterioration in patients with unstable C-spine fracture are widespread (“he turned his head and suddenly became paralyzed”), this has never been reported in the literature during the EMS interval; a small number of similar reports exist after hospital admission [see Harrop, Bohlman, and Davis for examples], but never before. One study [Toscano 1988] directly asserts that such injuries are common, but is terse and difficult to extrapolate from.
The following points are generally accepted, including by authorities such as the NAEMSP, PHTLS, American Association of Neurological Surgeons (AANS), and Cochrane Review:
- There is little to no evidence for the benefit of prehospital spinal immobilization.
- Despite this, its theoretical benefit, coupled with the potentially catastrophic harm — and catastrophic liability — of its absence supports its use on precautionary grounds.
- Penetrating trauma patients generally should not be immobilized; this has been shown to clearly increase their mortality [search for penetrating, but see especially Haut].
Updates
To view newly added material, search for the triple asterisk (***)
[5-13-13] 2 papers added
[4-18-13] 1 paper added
[4-2-13] 1 paper added
[3-26-13] Shelf created. 6 papers added.
Index
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