GLass intact Assures Safe cervical Spine protocol.

Background: Selective cervical spine immobilization performed by Emergency Medical Services (EMS) is being utilized with increasing frequency. These protocols, although very sensitive, still include subjective data such as "mild cervical discomfort." The aim of this study is to create an objective clinical decision rule that would enhance the selective approach for cervical spine immobilization in patients aged 16-60 years.

Study Objective: It is hypothesized that, in a motor vehicle crash, the integrity of the involved vehicle's glass window and airbag status is an excellent objective measure for the amount of energy a vehicle occupant has experienced during the crash. GLass intact Assures Safe Spine (GLASS) is an easy and objective method for evaluation of the need for prehospital cervical spine immobilization.

Methods: A retrospective cohort study was performed with sample motor vehicle crash cases to evaluate the performance of the GLASS rule. The National Accident Sampling System-Crashworthiness Data System (NASS-CDS) was utilized to investigate tow-away motor vehicle crashes, including their glass damage characteristics and occupant injury outcomes, over an 11-year period (1998-2008). Sample occupant cases selected for this study were patients aged 16-60 years, who were belt-restrained front seat occupants involved in a crash with no airbag deployment, and no glass damage before the crash.

Results: A total of 14,191 occupants involved in motor vehicle crashes were evaluated in this analysis. The results showed that the sensitivity of the GLASS rule was 95.20% (95% confidence interval [CI] 91.45-98.95%), the specificity was 54.27% (95% CI 53.44-55.09%), and the negative predictive value was 99.92% (95% CI 99.86-99.98%).

Conclusion: The GLASS rule presents the possibility of a novel, more objective tool for cervical spine clearance. Prospective evaluation is required to further evaluate the validity of this clinical decision rule.