In summary, for patients who received spinal immobilization:

Benefits in NNT

    No one benefitted
    No one benefitted

Harms in NNT

    10% higher risk of mortality
    1 in 10 were harmed (died)

View As:

Source: Velopulos CG, Shihab HM, Lottenberg L, Feinman M, Raja A, Salomone J, et al. Prehospital spine immobilization/spinal motion restriction in penetrating trauma: A practice management guideline from the Eastern Association for the Surgery of Trauma (EAST). J Trauma Acute Care Surg. 2018;84:736-744.

Study Population: 24 studies comprising 155,089 total patients.

Efficacy Endpoints: Mitigation of neurologic deficit and potentially reversible deficit.

Harm Endpoints: Mortality

Narrative: Spinal precautions are a key component of many emergency medical services (EMS) protocols.1, 2 However, there is limited evidence regarding the ability of spinal immobilization (i.e. cervical collars and/or longboards) to improve patient outcomes among those with penetrating trauma, and spinal immobilization may increase complications.3, 4 These complications include increased intracranial pressure, local pressure injury, missed penetrating injury, and delay in the successful performance of vital procedures (e.g. endotracheal intubation).1, 3, 4 Moreover, even if a cervical spine collar or longboard is properly applied, patients are often not adequately immobilized.1 While prior evidence suggested that few EMS and emergency department (ED) providers were aware of the potential harms with spinal immobilization in penetrating trauma,5 it has not been established that this potentially harmful intervention actually improves patient-relevant outcomes.

Investigators for the Eastern Association for the Surgery of Trauma (EAST) conducted a systematic review and meta-analysis which included randomized controlled trials, prospective observational or retrospective studies, and case-control studies evaluating the effects of spinal immobilization in adults with penetrating trauma (gunshot or stab wounds).1 Patients >13 years were considered to be adults, as these patients are typically treated as adults in many centers. Spinal immobilization was defined as the use of a cervical collar and/or longboard. The primary outcomes were mortality, neurologic deficits, and potentially reversible neurologic deficits (defined as deficit that could be either improved or reversed with definitive spinal immobilization). Secondary outcomes included missed injury and failed intubation. If pooling of data was inappropriate (moderate to high heterogeneity), the authors conducted a qualitative instead of quantitative analysis.

The systematic review included studies (n=155,089) that met the inclusion criteria for qualitative analysis and five studies (n=46,092) were suitable for quantitative analysis.1 All included studies were retrospective. No study demonstrated a benefit of spinal immobilization for mortality and neurologic injury. The incidence of neurologic injury was low, ranging from 2 to 76 per 1,000 patients. Studies focusing on patients with head and neck injuries found a higher incidence of neurologic injury, with 136 to 204 per 1,000 patients. Rates of potentially reversible neurologic injury were consistently very low, as well. Quantitative analysis (meta-analysis) of the five appropriate studies found an increased risk of harm with regard to mortality (Relative Risk [RR]: 2.4, 95% confidence interval [CI], 1.07 to 5.4; absolute risk difference [ARD]: 10.1%, 95% CI, 0.5% to 31.7%; and number needed to harm [NNH]: 10). There was no statistically significant difference for neurologic deficit (RR: 4.16, 95% CI, 0.56 to 30.89) or potentially reversible deficit (RR: 1.19, 95% CI, 0.83 to 1.70), although the point estimates favored no immobilization. There were insufficient data to perform quantitative analysis regarding failed intubation or missed injury.

Caveats: While this meta-analysis suggests that spinal immobilization in penetrating trauma is associated with increased mortality and does not reduce the risk of neurologic injuries, several limitations should be noted. All the included studies were retrospective and thus subject to the limitations inherent in this study design. The majority of studies assumed that spinal immobilization was performed based on protocol, but few studies described the type or extent of immobilization. Many studies evaluated only the projected risk versus benefit through assessment of the presence of true injury. The studies varied in their definition of the “potential benefit” of spinal immobilization, especially in regard to potentially preventable neurologic deficits. Additionally, the meta-analysis did not analyze penetrating head injury and penetrating neck injury separately. Some studies utilized surgical fixation as a surrogate outcome for reversible neurologic deficit, but these studies found that fixation may have prevented worsening of injury that had already occurred, rather than reversing it.

Only five studies were designated for quantitative analysis. For mortality, the pooled estimate relied heavily on two studies,6, 7 one of which (n=45,284 patients) contributed most of the events.7 Moreover, a disproportionate number of patients were in the no-immobilization group versus the immobilization group. While the data suggest a number-needed-to-harm of 10, this may be related to bias in the single large retrospective study comprising the majority of the included patients.7 For mortality, the risk of bias was judged to below, and the quality of evidence moderate. For potentially reversible neurologic deficit, the risk of bias was low but the included studies varied widely in the definition of “potentially reversible”, which, given the rarity of injury, resulted in imprecision and wide CI’s.

Nevertheless, this analysis suggests that spinal immobilization in adults with penetrating trauma is associated with an increase in mortality and not only no benefit, but apparent actual harm in terms of neurologic deficit or potentially reversible neurologic deficits. We have thus assigned a color recommendation of Red (Harm > Benefits). Spinal immobilization is not recommended for routine use in penetrating trauma.

The original manuscript was published in Academic Emergency Medicine as part of the partnership between TheNNT.com and AEM.

Author: Brit Long, MD; Alex Koyfman, MD; Michael Gottlieb, MD, RDMS
Supervising Editors: Joshua Quaas, MD; Allan Wolfson, MD

Published/Updated: October 1, 2019

  1. The Title Bar

    The title bar is color-coded with our overall recommendation.

    • Green: Benefits outweigh risks.
    • Yellow: Unclear risk/benefit profile.
    • Red: Benefits do not outweigh risks.
    • Black: Obvious harms, no clear benefits.
  2. Tip content...