There are five commonly used protocols for ruling out possible spine injuries in the field: the Canadian C-spine Rule (CCR), the National Emergency X-Radiography Utilization Study (NEXUS) low-risk criteria (NEXUS), the modified Nexus criteria, the State of Maine criteria (also based on the NEXUS criteria), and the Wilderness Medical Society (WMS) algorithm (a combination of the CCR and NEXUS). All are backed by solid research, in common use, and summarized below; click on an image to enlarge it.
Here's a quick summary of the differences: The CCR primarily focuses on ruling out the potential for a cervical spine injury by looking closely at the mechanism of injury. The NEXUS, modified NEXUS, State of Maine protocols, and the WMS guidelines assume a spine injury and focus on ruling it out via signs and symptoms. The difference between the NEXUS and modified NEXUS is the NEXUS study focuses on the cervical spine while the modified NEXUS has been adapted for the entire spine. The original NEXUS criteria does not include assessing the patient's spine pain, the modified NEXUS does and, as such, is more conservative than the NEXUS. The State of Maine criteria adds paraspinal tenderness to the mix, while the WMS guideline is a combination of the CCR and modified NEXUS. The term focused spine assessment (FSA) is somewhat generic and may refer to any of the above protocols.
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