Impact of cervical spine immobilization on clinical outcomes in traumatic brain injury patients according to prehospital mean arterial pressure: A multinational and multicenter observational study.

Cervical spine immobilization (CSI) has been considered an essential part of first aid management after severe trauma; however, the routine use of CSI for traumatic brain injury (TBI) patients is a matter of debate. The purpose of our study was to analyze the effect of CSI on the clinical outcomes of TBI patients and to analyze whether this effect depends on the prehospital mean arterial pressure (MAP) This was a prospective multi-national, multi-center cohort study using Pan-Asian trauma outcome study registry in Asian-Pacific, conducted on adult trauma patients. The main exposure was the implementation of CSI before hospital arrival. The main outcome was poor functional recovery at hospital discharge measured by the modified rankin scale. We performed multilevel logistic regression analysis to estimated the effect size of CSI for study outcomes. Interaction analysis between CSI and MAP on study outcomes were also conducted. CSI for TBI patients is significantly associated with an increased poor functional outcome (adjusted odd ratio, 95% confidence intervals: 1.23 [1.03 - 1.44]). The association of CSI with poor functional outcomes was maintained only in patients with decreased prehospital MAP (1.38 [1.14 - 1.56]), but not in patients with normal MAP (1.12 [0.93 - 1.24]) (P for interaction < .05). Routine use of CSI for patients with TBI, but without cervical spine injury, is associated with poor functional outcomes, but is significant only when the MAP, measured at the scene, was decreased.