Session IX - Spine

Cervical Spine Clearance in the Obtunded Patient

John B. Sledge, MD; Scott Dupar, MD; Boston Medical Center, Boston, Massachusetts, USA

Purpose: We developed a protocol for evaluating unexaminable patients with potential cervical spine injuries within 72 hours. We derived this protocol from a critical review of the clinical literature and assessed its sensitivity by performing a feasibility study.

Method: A systematic review was performed of the literature published over the past 15 years, and 42 articles related to cervical spine clearance were reviewed. A master grid was created containing all of the relevant information from the articles. A panel of physicians from emergency medicine, general surgery, critical care, and orthopaedics derived a flow diagram to balance the efficacy and efficiency of the protocol. The protocol was based on several assumptions. We would wait for a clinical examination if the patient were going to become examinable within 72 hours. If the patient were going to the operating room, we would use dynamic fluoroscopic flexion and extension films; if not, we would use either a CT scan or an MRI, depending on both the mechanism of injury and the associated injuries. Thus, patients would have a decision within 72 hours as to the stability of their cervical spine.

Results: We enrolled the first 300 patients who came for treatment to a level I trauma center and whose cervical spine could not be initially assessed and cleared by a physical examination. Of the 300 patients enrolled, complete data sets were obtained for 226 patients. Fifth-seven patients (19%) were lost to follow-up; 51 (89%) of the 57 did not keep outpatient appointments after discharge from the emergency department with negative results on plain radiographs but persistent midline neck tenderness. Eleven patients (3.7%) were treated without following the protocol (8 of these 11 occurred early in the study, and the remaining 3 had emergent CT scans and MRIs because of spinal cord injuries); 6 patients (2%) died during the protocol. Of 212 patients who were cleared and seen in follow-up, 3 patients were later found to have cervical injuries, 2 had facet injuries that were missed on MRI, and 1 had a disk disruption that was missed on CT. Fourteen of the 300 patients (4.7%) were identified as having either an injury to the cervical spine or to the cervical spinal cord that had been missed during the initial evaluation. Two patients who were discharged from the emergency room with hard collars were found to have ligamentous instability on follow-up. Twenty-two patients completed the protocol after 72 hours.

Discussion: A flow diagram was derived after a critical review of the literature to assist in ruling out cervical instability in the obtunded patient within 72 hours. One true case of missed cervical instability occurred when a CT study failed to detect a C7-T1 disk disruption. CT scans missed several neural element injuries, and MRI missed two facet fractures, but in none of these cases was the cervical spine unstable. Evaluating the results is difficult because the primary endpoint was the determination of cervical instability. Most of the central cord syndromes that were treated were missed on CT scan, but most of these occurred in patients with stable spines, which raises the question of whether these spines were really stable if they allowed for injury to the neural elements. We are now in the process of setting up a multicenter study to generate the numbers required to compare different imaging modalities and to assess both cervical instability and neurologic injury.