Clinical scenario

A 20 year old man is brought into the emergency department having been hit by a high speed vehicle while crossing the road. He has a large haematoma to the head and is confused and combative. Plain radiographs of his cervical spine are normal, as are radiographs of his chest and pelvis. You request a CT brain scan and a CT of his upper cervical spine, as you have heard that plain radiographs can miss injuries in this area. The radiologist does not agree that this is indicated as the plain radiographs of the cervical spine appear normal. You wonder if there is any evidence to support your request.

Three part question

In [trauma patients with altered mental status] is [plain radiography as good as CT] at [diagnosing significant upper cervical spine injuries]?

Search strategy

Medline 1966–07/02 using the OVID interface. [Exp spinal injuries OR exp spinal fractures OR {(exp odontoid process OR exp axis OR exp atlas OR exp atlanto-axial joint OR exp cervical vertebrae OR odontoid.mp OR cervical.mp OR dens.mp OR cervical spine.mp) AND (exp “wounds and injuries” OR trauma.mp OR exp fractures OR exp fractures, closed OR exp dislocations OR fracture$.mp OR dislocation$.mp)}] AND [exp confusion OR exp coma OR exp coma, post-head injury OR exp craniocerebral trauma OR head trauma.mp OR exp brain injuries OR head inj.mp OR exp intubation, intratracheal OR exp intubation OR exp delirium, dementia, amnestic, cognitive disorders OR altered mental status.mp OR unconscious.mp OR intubated.mp OR rapid sequence induction.mp OR coma.mp OR confusion.mp OR unevaluable.mp] AND [(exp “sensitivity-and-specificity” OR sensitivity.mp OR exp diagnosis OR exp pathology OR specificity.mp) OR exp tomography, x-ray computed OR computed tomography.mp OR exp x-rays OR x-ray$.mp] LIMIT to human AND English.

Search outcome

Altogether 572 papers were found of which 566 were irrelevant or of insufficient quality for inclusion. The remaining six papers are shown in table 2.

Comment(s)

The results of most of the studies outlined above indicate that in high risk patients with reduced level of consciousness there is an incidence of upper cervical spine injury between 5.2% and 13.9% (with the patients in the study by Berne et al having an incidence of 35%). The sensitivity of plain rdiograph has usually been found to be between 39% and 61%. If the incidence of cervical spine injury is estimated as 8%, and the sensitivity of plain films taken to be 50%, this means that 4%, or 1 in 25, of polytrauma patients with a reduced level of consciousness will have an upper cervical spine injury not evident on plain rdiographs. The missed spinal injuries included unstable fractures in all studies where stability was considered. It should be noted that not all studies limited themselves to the upper cervical spine, though the majority of missed injuries occurred either here or in the C7/T1 region, where this could not be adequately visualised on plain radiographs. Further studies involving helical CT scanning of the entire cervical spine are planned.

Possible drawbacks of routine CT imaging of the upper cervical spine include adverse events occurring as a result of spending longer periods in the CT scanner. Such events were not specifically sought in any of the studies described. Spiral CT scanners, with faster scanning times, should minimise this risk. In addition, CT scans cannot be used to reliably exclude ligamentous injuries—other imaging modalities are required for this.

▸ CLINICAL BOTTOM LINE

The upper cervical spine should be scanned during CT scanning of the head in the polytraumatised patient with reduced level of consciousness.