Study design: Retrospective cohort study.
Objective: To determine the frequency of injuries missed by initial computed tomography (CT) of the cervical spine in obtunded blunt trauma victims.
Summary of background data: Optimal method for excluding cervical spine injury in obtunded trauma patients remains controversial. Trauma centers show marked variation in spine clearance protocols.
Methods: We reviewed medical records of consecutive obtunded blunt trauma victims admitted over 2 years to a level 1 trauma center and selected patients who had CT imaging of the cervical spine during their initial emergency room evaluation. We excluded patients in whom this study identified an injury and also patients who became examinable before subsequent imaging with upright cervical spine radiographs, as required by institutional protocol. Using composite reference standard of cervical injury diagnosed by subsequent imaging or clinical examinations by the time of discharge from the hospital, we evaluated the frequency and type of injuries missed by the initial CT and the delay in spine clearance due to additional imaging.
Results: Of 590 screened patients, 367 met the inclusion and exclusion criteria. The study cohort had mean age 40.2 years (SD 20.8), 75.5% males, mean Glasgow Coma Scale score 5.9 (SD 3.4), and mean Injury Severity Scale score 24.5 (SD 10). Initial CT imaging failed to identify an injury in 1 patient, for a false negative rate of 0.3% (1/367): a cervical cord contusion identified on subsequent physical examination, confirmed by magnetic resonance imaging, and managed nonoperatively. Upright cervical spine radiographs did not identify any injuries missed by CT, but they delayed spine clearance by a mean of 2.6 days and by more than 48 hours in 42% of the patients.
Conclusion: Initial CT imaging identified all unstable cervical spine injuries in obtunded trauma patients. Subsequent upright radiographs did not identify any additional injuries but significantly delayed spine clearance.