Original Research
Prospective Performance Assessment of an Out-of-Hospital Protocol for Selective Spine Immobilization Using Clinical Spine Clearance Criteria

https://doi.org/10.1016/j.annemergmed.2005.02.004Get rights and content

Study objective

We determine whether the use of an emergency medical services (EMS) protocol for selective spine immobilization would result in appropriate immobilization without spinal cord injury associated with nonimmobilization.

Methods

A 4-year prospective study examined EMS and hospital records for patients after the implementation of an EMS protocol for selective spine immobilization. EMS personnel were trained to perform and document a spine injury assessment for out-of-hospital trauma patients with a mechanism of injury judged sufficient to cause a spine injury. The assessment included these clinical criteria: altered mental status, evidence of intoxication, neurologic deficit, suspected extremity fracture, and spine pain or tenderness. The protocol required immobilization for patients with a positive assessment on any of those criteria. Outcome characteristics included the presence or absence of spine injury and spine injury management.

Results

The study collected data on 13,483 patients; 126 of the patients were subsequently excluded from the study because of incomplete data, leaving a study sample of 13,357 patients with complete data. Spine injuries were confirmed in the hospital records for 3% (n=415) of patients, including 50 patients with cord injuries and 128 patients with cervical injuries. Sensitivity of the EMS protocol was 92% (95% confidence interval [CI] 89.4 to 94.6%) resulting in nonimmobilization of 8% of the patients with spine injuries (33 of 415). None of the nonimmobilized patients sustained cord injuries. The specificity was 40% (95% CI 38.9 to 40.5%).

Conclusion

The use of our selective immobilization protocol resulted in spine immobilization for most patients with spine injury without causing harm in cases in which spine immobilization was withheld.

Introduction

Spine immobilization as a precaution to prevent worsening of an unstable spine fracture or spinal cord injury has been the standard emergency medical services (EMS) treatment of trauma patients for more than 20 years.1 Historically, the decision to perform spine immobilization has been based on the potential for spine injury as determined by the mechanism of injury.2

Although there is no proven benefit of spine immobilization, there is significant evidence of morbidity caused by the procedure itself. Immobilization has been demonstrated to cause back and head pain, resulting in an increased number of radiographs required to clear the spine in the emergency department (ED).3, 4, 5 Rigid spine immobilization can also cause pressure-related tissue breakdown, restrict respirations, and, if used aggressively, actually cause spinal cord injury.6, 7

ED studies have confirmed the ability of clinical criteria to reliably determine the need for spine radiographs, although the majority of these have addressed only the cervical spine.8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22 Hoffman et al22 reported that only a small number of patients with cervical spine injury escaped capture using clinical clearance criteria in the ED.22 Although the ED use of clinical spine clearance protocols has been reported,23 the validity of using a similar protocol in the EMS setting has not been fully addressed. Relying on the results of studies from our institution, Michigan's Washtenaw/Livingston Medical Control Authority develop an EMS protocol for selective immobilization.24, 25, 26

This study investigated whether the use of an EMS protocol for selective immobilization resulted in appropriate immobilization without spinal cord injury associated with nonimmobilization.

Section snippets

Study Design

This study prospectively examined outcome data on consecutive trauma patients who were evaluated using the southeastern Michigan EMS spine injury assessment protocol.

In October 1997, the Washtenaw/Livingston Medical Control Authority implemented a spine injury assessment protocol for determining which trauma patients had indication for spine immobilization. All EMS personnel received training in the appropriate use of this protocol. The spine injury assessment consists of 5 clinical criteria:

Results

During the study period, 18,594 trauma patients were transported by our ALS services to hospitals within the EMS system. There were documented spine injury assessments for 13,483 of these trauma patients, making them eligible for enrollment in the study. Among this group, 126 patients were excluded from the study because of missing data, including 75 patients who died before radiographic evaluation, which left 13,357 patients with complete data (Figure 2).

Patients ranged in age from younger

Limitations

There were 75 patients who were excluded from the study because of death before spine evaluation. No radiographs were obtained for these patients, and no autopsy reports were collected. All but 1 of these patients had EMS spine immobilization, making moot speculation that perhaps withheld immobilization and resultant spinal cord injury contributed to the deaths.

Not all spine injury assessments were recorded using the documentation table printed on the EMS patient record as instructed. An

Discussion

Our selective immobilization protocol27 asks EMS providers to evaluate patients for the presence of a mechanism of injury sufficient to cause spine injury and perform a spine injury assessment in these patients. The spine injury assessment consists of an evaluation of these 5 clinical criteria:

  • altered mental status

  • evidence of intoxication

  • a suspected extremity fracture proximal to the wrist or ankle

  • neurologic deficit

  • spine pain or tenderness

The first 3 criteria establish that the patient is alert

References (30)

  • J.R. Hoffman et al.

    Low-risk criteria for cervical-spine radiography in blunt trauma: a prospective study

    Ann Emerg Med

    (1992)
  • G. Stroh et al.

    Can an out-of-hospital cervical spine clearance protocol identify all patients with injuries? an argument for selective immobilization

    Ann Emerg Med

    (2001)
  • American Academy of Orthopedic Surgeons

    Committee on injuries. Fractures and dislocations of the spine

  • J.J. Augustine

    Spinal trauma

  • R.N. Barney et al.

    Pain associated with immobilization on rigid spine boards

    Ann Emerg Med

    (1989)
  • Cited by (0)

    Supervising editor: Donald M. Yealy, MD

    Author contributions: RMD and SMF conceived and initiated the study. RMD performed all initial and injury medical record reviews and drafted the manuscript. SMF reviewed all EMS patient records and obtained all patient outcomes and reviewed the data, statistical information, and manuscript. KW was the statistical consultant for the study and reviewed the study design, performed the statistical analysis, and reviewed the manuscript. RMD takes responsibility for the paper as a whole.

    Funding and Support: This work was generously supported by the St. Joseph Mercy Hospital Emergency Department Research Fund and the Clinical Research Fund.

    Presented at the Society of Academic Emergency Annual Meeting, May 2002, St. Louis, MO.

    Reprints not available from the authors.

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