Brief Reports THE EFFECT OF CRICOID PRESSURE ON THE UNSTABLE CERVICAL SPINE Mark L. Prasarn, MD,* MaryBeth Horodyski, EDD, ATC,† Prism Schneider, MD, PHD,* Adam Wendling, MD,‡ Carin A. Hagberg, MD,§ and Glenn R. Rechtine, MDk *Department of Orthopaedic Surgery, University of Texas, Houston, Texas, †Department of Orthopaedic Surgery, University of Florida, Gainesville, Florida, ‡Department of Anesthesiology, University of Florida, Gainesville, Florida, §Department of Anesthesiology, University of Texas, Houston, Texas, and kDepartment of Orthopaedic Surgery, Veterans Affairs Hospital, Asheville, North Carolina Reprint Address: Mark L. Prasarn, MD, Department of Orthopaedic Surgery, University of Texas, 6400 Fannin Suite 1700, Houston, TX 77030 , Abstract—Background: It has been proposed that cricoid pressure can exacerbate an unstable cervical injury and lead to neurologic deterioration. Objective: We sought to examine the amount of motion cricoid pressure could cause at an unstable subaxial cervical spine injury, and whether posterior manual support is of any benefit. Methods: Five fresh, whole cadavers had complete segmental instability at C5–C6 surgically created by a fellowship-trained spine surgeon. Cricoid pressure was applied to the anterior cricoid by an attending anesthesiolo- gist. In addition, the effect of posterior cervical support was tested during the trials. The amount of angular and linear motion between C5 and C6 was measured using a Fastrak, three-dimensional, electromagnetic motion analysis device (Polhemus Inc., Colchester, VT). Results: When cricoid pressure is applied, the largest angular motion was 3 degrees and occurred in flexion-extension at C5–C6. The largest linear displacement was 1.36 mm and was in anterior- posterior displacement of C5–C6. When manual posterior cervical support was applied, the flexion-extension was improved to less than half this value (1.43 degrees), and this reached statistical significance (p = 0.001). No other dif- ferences were observed to be significant in the other planes of motion with the applications of support. Conclusions: Based on the evidence presented, we believe that the applica- tion of cricoid pressure to a patient with a globally unstable subaxial cervical spine injury causes small displacements. There may be some benefit to the use of manual posterior cervical spine support for reducing motion at such an injured segment. Ó 2016 Elsevier Inc. , Keywords—cricoid pressure; airway; aspiration; cervi- cal spine; injury INTRODUCTION Optimal management of the airway in trauma victims with cervical spine injuries has been debated. Crosby published a review concluding that a variety of airway- management strategies are safe and acceptable (1). In addition, manual in-line stabilization with application of cricoid pressure was recommended to reduce the risk of aspiration by preventing both gastric insufflation dur- ing bag-valve-mask ventilation and passive regurgitation of gastric contents (1). Despite this, there is concern that cricoid pressure can exacerbate an unstable cervical spine injury and lead to permanent neurologic injury or ‘‘harm- ful conversion’’ (2–4). Even though this is a major concern for medical professionals involved with airway management of trauma patients, it is also expected that all measures to prevent aspiration will be taken if the need arises. Aspiration in any patient can result in devastating medical morbidity and possibly mortality. Previous studies of cervical spine movement with application of cricoid pressure in cadaveric models have been radiographic and based solely on anterior- posterior displacement or flexion-extension angulation; essentially examining only one plane of motion and RECEIVED: 9 June 2015; FINAL SUBMISSION RECEIVED: 28 August 2015; ACCEPTED: 4 September 2015 427 The Journal of Emergency Medicine, Vol. 50, No. 3, pp. 427–432, 2016 Copyright Ó 2016 Elsevier Inc. Printed in the USA. All rights reserved 0736-4679/$ - see front matter http://dx.doi.org/10.1016/j.jemermed.2015.09.009