Application of National Emergency X-Ray Utilizations Study low-risk c-spine criteria in high-risk geriatric falls

Abstract

Study objectives

We sought to validate National Emergency X-Radiography Utilizations Study low-risk cervical spine (C spine) criteria in a geriatric trauma population. We sought to determine whether patients' own baseline mental status (MS) could substitute for Glasgow Coma Scale (GCS) to meet the criteria “normal alertness.” We further sought to refine the definition of “distracting injury.”

Methods

This is a retrospective review of geriatric fall patients presenting to a level 1 trauma center and triaged to the trauma bay. We queried our database from 2008 to 2013. Abstractors recorded GCS, deviation from baseline MS, midline neck tenderness, intoxication, focal deficit, signs of trauma, and presence of other injury. Patients were considered at baseline MS if specific documentation was present on the chart, or if their GCS was 15.

Results

Six hundred sixty elderly fall patients were trauma alerts during the study period. Seventeen were excluded for incomplete records/death before imaging, leaving 647. The median age was 81 (interquartile range, 74-87). Fifty patients (8.0%) had C spine or cord injury. Two hundred ninety-four (44.5%) had baseline MS (including GCS 13-15), no spine tenderness, no intoxication, and no focal neurologic deficit. Of these, 18 had C-spine injury. Using physical findings of head trauma as the only “distracting injury,” no injury would have been missed (sensitivity, 100% [confidence interval, 91.1-100]; specificity, 14.2%).

Conclusions

Our study suggests that National Emergency X-Radiography Utilizations Study can be safely applied in elderly fall patients who are at their personal baseline MS. Furthermore, our data support a more narrow definition of distracting injury to include only patients with signs of trauma to the head.

Introduction

The National Emergency X-Radiography Utilizations Study (NEXUS) criteria, developed in the early 90s, is a clinical decision tool emergency medicine physicians use to safely rule out cervical spinal injuries (CSI) in the blunt traumatic patient without radiographic imaging [1]. The NEXUS criteria are met if a patient denies posterior cervical tenderness on palpation, is not intoxicated, has normal alertness, has no focal neurologic deficits, and has no painful distracting injuries. The NEXUS has demonstrated effectiveness at finding cervical spine injuries, with a sensitivity of 99.6% in a large prospective trial [2], [3].

Since the introduction of NEXUS, several studies have questioned its reliability in detecting CSI in elderly (≥ 65 years) patients [4], [5]. Elderly patients often have CSI from lower mechanisms of injury, such as falls, lacking the more obvious, and comorbid distracting injuries that would otherwise make them NEXUS positive [5]. Older age is an independent risk factor for CSI in blunt trauma and is a commonly cited reason for failing to apply NEXUS in clinical care [3], [6].

The application of NEXUS clinically is subject to variability due to the subjective nature of “altered alertness [7].” In fact, some studies on NEXUS include “evaluable patients” with Glasgow Coma Scale (GCS) as low as 13 as NEXUS negative [8], whereas the original criteria describe altered alertness as patients having a GCS of 14 or less [1]. This has direct implications on geriatric trauma care. A large proportion of elderly patients have baseline cognitive impairment, and it is unclear whether NEXUS can be safely applied in the elderly patient with a GCS less than 15 who is at their personal baseline mental status (MS) [9], [10], [11].

The interpretation of distracting injury is also subjective and is intentionally vaguely defined in the original NEXUS criteria [7], [2]. Some studies have attempted to narrow the subjective definition of distracting injuries to limit them to upper torso trauma, but, currently, there is no standard agreement for what denotes distracting injury [8], [12], [13].

Our current study aims to validate NEXUS criteria in geriatric fall patients triaged to the trauma bay at a level 1 trauma center. We sought to identify whether GCS less than 15 in a patient described at their personal baseline MS altered the sensitivity/specificity of the NEXUS criteria. We additionally sought to determine if narrowing the definition of “distracting painful injury” to “any observable trauma to the head or face” had any impact on the sensitivity/specificity of NEXUS in this population.