NEXUS Criteria (C-spine)

The NEXUS Criteria (National Emergency X-Radiography Utilization Study) is one of the two major clinical decision rules used to evaluate patients for potential cervical spine injury after blunt trauma. Developed through a landmark multicenter prospective study involving 34,069 patients across 21 US emergency departments, the NEXUS criteria were published in 2000 in the New England Journal of Medicine.

The NEXUS study was one of the largest prospective clinical decision rule validation studies ever conducted in emergency medicine. Among the 34,069 enrolled patients, 818 (2.4%) had cervical spine injuries, including 578 with clinically significant injuries. The study demonstrated that the five NEXUS low-risk criteria could identify patients who did not need cervical spine imaging with a sensitivity of 99.0% for clinically significant injuries.

The NEXUS criteria are elegantly simple, consisting of five clinical findings. If ALL five criteria are absent, the patient is considered low-risk and cervical spine imaging can be safely omitted. The five criteria are: midline cervical spine tenderness, focal neurological deficit, altered level of alertness, intoxication, and clinically apparent distracting injury. The absence of all five criteria indicates a very low probability of clinically significant cervical spine fracture.

One of the advantages of the NEXUS criteria over the competing Canadian C-Spine Rule is their simplicity and ease of application. The five criteria can be assessed quickly at the bedside without complex algorithmic thinking. This makes NEXUS particularly useful in busy emergency departments and by less experienced clinicians. However, the Canadian C-Spine Rule has been shown to be more specific (fewer unnecessary imaging studies) while maintaining similar sensitivity.

The concept of distracting injury in NEXUS has been a subject of debate. The original study did not provide a strict definition, instead relying on physician judgment. Generally, a distracting injury is one that is sufficiently painful that it may distract the patient from recognizing cervical spine pain. Examples include long bone fractures, large lacerations, crush injuries, visceral injuries, and large burns. This ambiguity has been both criticized and defended in the literature.

The NEXUS criteria have been adopted worldwide and are particularly popular in the United States. They are endorsed by the American College of Surgeons Committee on Trauma and included in the Advanced Trauma Life Support (ATLS) curriculum. While the Canadian C-Spine Rule may be technically superior in comparative studies, NEXUS remains widely used due to its simplicity and extensive validation.