ORIGINAL ARTICLE Cervical Spine Clearance in Obtunded Blunt Trauma Patients: A Prospective Study Deirdre Hennessy, MSc, Sandy Widder, MD, FRCSC, David Zygun, MD, MSc, FRCPC, R. John Hurlbert, MD, FRSCS, Paul Burrowes, MD, FRCPC, and John B. Kortbeek, MD, FRCSC Background: An acceptable algorithm for clearance of the cervical spine (C-spine) in the obtunded trauma patient remains controversial. Undetected C-spine injuries of an unstable nature can have devastating consequences. This has led to reluctance toward C-spine clearance in these patients. Objective: To objectify the accuracy of computed tomography (CT) scan- ning compared with dynamic radiographs within a well established C-spine clearance protocol in obtunded trauma patients at a level I trauma center. Methods: This was a prospective study of consecutive blunt trauma patients (18 years or older) admitted to a single institution between December 2004 and April 2008. To be eligible for study inclusion, patients must have undergone both a CT scan and dynamic plain radiographs of their C-spine as a part of their clearance process. Results: Among 402 patients, there was one injury missed on CT but detected by dynamic radiographs. This resulted in a percentage of missed injury of 0.25%. Subsequent independent review of the CT scan revealed that in fact pathologic changes were present on the scan indicative of the injury. Conclusions: Our results indicate that CT of the C-spine is highly sensitive in detecting the vast majority (99.75%) of clinically significant C-spine injuries. We recommend that CT be used as the sole modality to radiograph- ically clear the C-spine in obtunded trauma patients and do not support the use of flexion-extension radiographs as an ancillary diagnostic method. Key Words: Cervical spine injury, Cervical spine clearance, CT scanning, Dynamic radiographs, Obtunded patients. (J Trauma. 2010;68: 576 –582) D espite marked improvements in patient care, advances in technology, and numerous studies performed during the past decades, an algorithm for clearance of the cervical spine (C-spine) in obtunded trauma patients remains controversial. Awake, alert trauma patients without a distracting injury can be cleared in the presence of a normal neurologic examina- tion and the absence of any pain or tenderness on full range of motion of the neck. Patients with an altered mental status, however, cannot be cleared by clinical examination alone. Missing an unstable C-spine injury can have devastating consequences for the patient and their families. As a result, there has been a defensible reluctance to clear the C-spine in obtunded trauma patients. Multiple studies have focused on the various modalities including plain films, computed to- mography (CT) scanning, flexion-extension (F-E) views, and magnetic resonance imaging (MRI). 1–4 To date, there is no gold standard for C-spine clearance in this patient population. Unfortunately, delays in C-spine clearance contribute to increased patient morbidity by way of prolonged immobi- lization. These morbidities include decubitus ulcers, deep vein thrombosis, and respiratory complications. In addition, patients can be jeopardized by challenges and complications caused by maintaining cervical immobilization in a collar including skin breakdown, difficult airway, obstructed central venous access, and aspiration risks. 5 Furthermore, there is an economical burden related to these complications and addi- tional costs related to postponed surgical procedures, sus- pended treatments, and longer lengths of intensive care unit (ICU) and hospital stay. 6 In 2004, the University of Calgary Trauma Service performed a prospective study of consecutive intubated blunt trauma patients admitted to ICU looking at the utility of CT versus plain radiographs in C-spine clearance in the obtunded trauma patient. 1 The study demonstrated that CT was superior to plain films alone, because plain films tended to be fre- quently inadequate and unable to visualize the entire C-spine. Based on these results and the Eastern Association for the Surgery of Trauma recommendations at the time, 7 the C- spine clearance algorithm for obtunded blunt trauma patients was redesigned to reflect current best practice by including a CT scan of the entire C-spine and F-E views to rule out ligamentous injury in the absence of any bony pathology. More recent evidence has suggested that CT scanning alone may be adequate to safely discontinue C-spine precautions and that ancillary imaging may substantially delay spinal clearance and increase costs. 2,3,6,8 –10 However, these studies have been relatively small, 2,3,10 many of them have been retrospective in design, 8,9 and they did not necessarily com- pare a protocol including dynamic radiographs with CT scanning. 2,9 This study was unique in two respects; first, it was an effectiveness study that assessed the accuracy of CT scanning within a well-established C-spine clearance protocol in a real practice setting, where radiology reports were not rereviewed, except in the case of a missed injury; second, the study team a priori decided on a rate of missed injury, above Submitted for publication September 11, 2009. Accepted for publication December 14, 2009. Copyright © 2010 by Lippincott Williams & Wilkins From the Departments of Critical Care Medicine (D.H., S.W., D.Z., J.B.K.), Clinical Neurosciences (D.Z., R.J.H.), Radiology (P.B.), and Surgery (J.B.K.), University of Calgary, Calgary, Alberta. Presented at the Annual Scientific Meeting of the Trauma Association of Canada, March 5–7, 2009, Auckland, New Zealand. Address for reprints: J. B. Kortbeek, Department of Surgery, Faculty of Medicine, University of Calgary, 10 th Floor, North Tower, 1403-29 th St. NW, Calgary, AB, T2N 2T9; email: john.kortbeek@albertahealthservices.ca. DOI: 10.1097/TA.0b013e3181cf7e55 576 The Journal of TRAUMA ® Injury, Infection, and Critical Care • Volume 68, Number 3, March 2010