The out-of-hospital validation of the Canadian C-Spine Rule by paramedics.

Study objective: We designed the Canadian C-Spine Rule for the clinical clearance of the cervical spine, without need for diagnostic imaging, in alert and stable trauma patients. Emergency physicians previously validated the Canadian C-Spine Rule in 8,283 patients. This study prospectively evaluates the performance characteristics, reliability, and clinical sensibility of the Canadian C-Spine Rule when used by paramedics in the out-of-hospital setting. Methods: We conducted this prospective cohort study in 7 Canadian regions and involved alert (Glasgow Coma Scale score 15) and stable adult trauma patients at risk for neck injury. Advanced and basic care paramedics interpreted the Canadian C-Spine Rule status for all patients, who then underwent immobilization and assessment in the emergency department to determine the outcome, clinically important cervical spine injury. Results: The 1,949 patients enrolled had these characteristics: median age 39.0 years (interquartile range 26 to 52 years), female patients 50.8%, motor vehicle crash 62.5%, fall 19.9%, admitted to the hospital 10.8%, clinically important cervical spine injury 0.6%, unimportant injury 0.3%, and internal fixation 0.3%. The paramedics classified patients for 12 important injuries with sensitivity 100% (95% confidence interval [CI] 74% to 200%) and specificity 37.7% (95% CI 36% to 40%). The K value for paramedic interpretation of the Canadian C-Spine Rule (n = 155) was 0.93 (95% CI 0.87 to 0.99). Paramedics conservatively misinterpreted the rule in 320 (16.4%) patients and were comfortable applying the rule in 1,594 (81.7%). Seven hundred thirty-one (37.7%) out-of-hospital immobilizations could have been avoided with the Canadian C-Spine Rule. Conclusion: This study found that paramedics can apply the Canadian C-Spine Rule reliably, without missing any important cervical spine injuries. The adoption of the Canadian C-Spine Rule by paramedics could significantly reduce the number of out-of-hospital cervical spine immobilizations. [Ann Emerg Med. 2009;54:663-671.]