Clearing the cervical spine in unconscious adult trauma patients: A survey of practice in specialist centres in the UK

‘Clearing’ the cervical spine in the unconscious trauma patient

This is a systemic review of the published evidence regarding cervical spine management in unconscious trauma patients. We examine the literature in the following sections: use of plain radiography; use of flexion/extenson views; use of computed tomography; use of magnetic resonance imaging. We also review surveys of practice and current guidelines.

In contrast to the conscious trauma patient there have been no large prospective multicentre studies to derive a clinical decision rule for the exclusion of cervical spine injury. This review therefore assesses currently available evidence to reach a logical conclusion regarding the most appropriate imaging strategy to exclude significant injury in the cervical spine, whilst minimising the time that a patient needs to remain immobilised.

Risks associated with magnetic resonance imaging and cervical collar in comatose, blunt trauma patients with negative comprehensive cervical spine computed tomography and no apparent spinal deficit

INTRODUCTION

In blunt trauma, comatose patients (Glasgow Coma Scale score 3 to 8) with a negative comprehensive cervical spine (CS) computed tomography assessment and no apparent spinal deficit, CS clearance strategies (magnetic resonance imaging [MRI] and prolonged cervical collar use) are controversial.

METHODS

We conducted a literature review to delineate risks for coma, CS instability, prolonged cervical collar use, and CS MRI.

RESULTS

Based on our search of the literature, the numbers of functional survivor patients among those who had sustained blunt trauma were as follows: 350 per 1,000 comatose unstable patients (increased intracranial pressure [ICP], hypotension, hypoxia, or early ventilator-associated pneumonia); 150 per 1,000 comatose high-risk patients (age > 45 years or Glasgow Coma Scale score 3 to 5); and 600 per 1,000 comatose stable patients (not unstable or high risk). Risk probabilities for adverse events among unstable, high-risk, and stable patients were as follows: 2.5% for CS instability; 26.2% for increased intensive care unit complications with prolonged cervical collar use; 9.3% to 14.6% for secondary brain injury with MRI transportation; and 20.6% for aspiration during MRI scanning (supine position). Additional risk probabilities for adverse events among unstable patients were as follows: 35.8% for increased ICP with cervical collar; and 72.1% for increased ICP during MRI scan (supine position).

CONCLUSION

Blunt trauma coma functional survivor (independent living) rates are alarming. When a comprehensive CS computed tomography evaluation is negative and there is no apparent spinal deficit, CS instability is unlikely (2.5%). Secondary brain injury from the cervical collar or MRI is more probable than CS instability and jeopardizes cerebral recovery. Brain injury severity, probability of CS instability, cervical collar risk, and MRI risk assessments are essential when deciding whether CS MRI is appropriate and for determining the timing of cervical collar removal.

Clearing the cervical spine in obtunded patients

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To determine the frequency of injuries missed by initial computed tomography (CT) of the cervical spine in obtunded blunt trauma victims.

SUMMARY OF BACKGROUND DATA

Optimal method for excluding cervical spine injury in obtunded trauma patients remains controversial. Trauma centers show marked variation in spine clearance protocols.

METHODS

We reviewed medical records of consecutive obtunded blunt trauma victims admitted over 2 years to a level 1 trauma center and selected patients who had CT imaging of the cervical spine during their initial emergency room evaluation. We excluded patients in whom this study identified an injury and also patients who became examinable before subsequent imaging with upright cervical spine radiographs, as required by institutional protocol. Using composite reference standard of cervical injury diagnosed by subsequent imaging or clinical examinations by the time of discharge from the hospital, we evaluated the frequency and type of injuries missed by the initial CT and the delay in spine clearance due to additional imaging.

RESULTS

Of 590 screened patients, 367 met the inclusion and exclusion criteria. The study cohort had mean age 40.2 years (SD 20.8), 75.5% males, mean Glasgow Coma Scale score 5.9 (SD 3.4), and mean Injury Severity Scale score 24.5 (SD 10). Initial CT imaging failed to identify an injury in 1 patient, for a false negative rate of 0.3% (1/367): a cervical cord contusion identified on subsequent physical examination, confirmed by magnetic resonance imaging, and managed nonoperatively. Upright cervical spine radiographs did not identify any injuries missed by CT, but they delayed spine clearance by a mean of 2.6 days and by more than 48 hours in 42% of the patients.

CONCLUSION

Initial CT imaging identified all unstable cervical spine injuries in obtunded trauma patients. Subsequent upright radiographs did not identify any additional injuries but significantly delayed spine clearance.