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Computer tomography and the exclusion of upper cervical spine injury in trauma patients with altered mental state

Three Part Question

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

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.

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 altered mental state.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.tw OR exp diagnosis OR exp pathology OR specificity.tw) 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

572 papers, of which 566 were irrelevant or of insufficient quality for inclusion. The remaining 6 papers are shown in the table.

Relevant Paper(s)

Author, date and country Patient group Study type (level of evidence) Outcomes Key results Study Weaknesses
Kirshenbaum KJ et al,
1990,
USA
50 consecutive patients with significant head trauma CT v radiographyProspective case seriesNumber of patients with significant upper cervical spine fractures4 v 0Sensitivity of CT not assessed
Woodring JH and Lee C,
1993,
USA
216 consecutive patients with acute traumatic fractures, subluxations or dislocations of cervical vertebrae, CT of entire cervical spine and plain films performed on all patients.Retrospective case seriesFractures seen at time on plain film trauma series39%Retrospective nature of study CT sensitivity not assessed
Fractures seen on plain films in retrospect58%
Subluxations and dislocations seen at time on plain films64%
Subluxations and dislocations seen on plain films in retrospect93%
Link TM et al,
1995,
Germany
202 patients with head injuries and GCS<7 37 (18.3% of patients) had fractures of occiptial candyles, C1 or C2Prospective consecutive seriesNumber of fractures of C1 or C2 identified by CT or radiography28 (13.9% of patients)Wide age range (3-86)
Number of fractures of C1 or C2 identified by plain radiographs alone17 (60.7% of those identified by CT)
Mean time to perform (conventional) CT of upper cervical spine8 minutes
Ajani AE et al,
1998,
Australia
91 major trauma patients with injuries to head or neck, or multiple injuries. 12 with abnormal or equivocal radiographs had CT scans. 48 unconscious or unco-operative with normal radiographs had passive flexion-extension views.Prospective consecutive case seriesTotal patients identified with unstable cervical injury6 (6.6%)CT not uniformly performed - possible that significant number of false negative radiographs missed.
Patients identified as having unstable cervical injury with normal initial radiographs by flexion-extension views1 (1.1%)
Berne JD et al,
1999,
USA
58 high-risk blunt trauma patients, with inability to evaluate cervical spine clinically. ICU. All patients underwent plain lateral and AP +/- odontoid view when possible in nonintubated patients, and subsequent complete cervical helical CT (C0 to T1) CT v radiographyProspective consecutive case seriesNumber of patients with stable injuries12 (20.7%)Radiographic protocol violations in 9 patients of original 67 meeting criteria
Number of patients with unstable injuries8 (13.8%)
Sensitivity18/20 (90%) v 12/20 (60%)
Specificity38/38 (100%) v 38/38 (100%)
Schenarts PJ et al,
2001,
USA
1356 blunt trauma patients, aged over 14, with altered mental status (mean GCS 11) requiring CT evaluation of 2 or more body systems. CT of C0-C3, in addition to five-view plain film series. CT v radiographyProspective consecutive case seriesNumber of patients in whom cervical spine injuries identified overall70 (5.2% of all eligible patients)Unblinded radiological review Haemodynamically unstable patients, those dying before plain films, those requiring immediate surgery excluded
Number of patients in whom cervical spine injuries identified67 v 38%

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 Berne et al's study having an incidence of 35%). The sensitivity of plain radiograph 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 radiographs. 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 visualized on plain x-rays. 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 minimize this risk. In addition, CT scans can not 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 polytraumatized patient with reduced level of consciousness.

References

  1. Kirshenbaum, KJ, Nadimpalli SR, Fantus R et al. Unsuspected cervical spine fractures associated with significant head trauma: role of CT. J Emerge Med 1990;8(2):183-198.
  2. Woodring JH, Lee C. Limitations of cervical radiography in the evaluation of acute cervical trauma. J Trauma Injury Infect Crit Care 1993;34(1):32-39.
  3. Link TM, Schuierer G, Hufendiek A, et al. Substantial head trauma: Value of routine CT examination of the cervicocranium. Radiology 1995;196(3):741-745.
  4. Ajani AE, Cooper DJ, Scheinkestel CD, et al. Optimal assessment of cervical spine trauma in critically ill patients: a prospective evaluation. Anaesth Intensive care 1998;26(5):498-491.
  5. Berne JD, Velmahos GC, El-Tawil Q, et al. Value of complete cervical helical computed tomographic scanning in identifying cervical spine injury in the unevaluable blunt trauma patient with multiple injuries: a prospective study. J of Trauma Inj Infect Critical Care 1999;47(5):896-903.
  6. Schenarts PJ, Diaz J, Kaiser C, et al. Prospective comparison of admission computed tomographic scan and plain films of the upper cervical spine in trauma patients with altered mental status. J of Trauma Inj Infect Critical Care 2001;51(4):663-669.