The Out-of-Hospital Validation of the Canadian C-Spine Rule by Paramedics

Abstract

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. 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. 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 100%) and specificity 37.7% (95% CI 36% to 40%). The kappa 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. 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.