The Canadian CT Head Rule

Clinical indicators for traumatic intracranial findings in mild traumatic brain injury patients

Background

Mild traumatic brain injury (MTBI), accounting for 80% of traumatic brain injury, is one of the most common conditions seen in emergency departments. Clinical parameters to predict intracranial lesions vary among guidelines. This study intended to find clinical parameters that can predict traumatic intracranial lesions in the setting of a middle-income country.

Methods

Data from mild head injury patients admitted to the emergency department from two large hospitals in Chiang Mai, Thailand, were prospectively collected from 2013 to 2014. The primary outcome was identifying clinically-important traumatic brain injury (ciTBI), and the secondary outcome was the neurosurgical procedure performed. Ten clinical findings and six predicting factors were analyzed using univariable and multivariable analysis.

Results

Among 1164 patients, ciTBI was identified in 244 cases (21.0%). The neurosurgical operation was performed in 57 cases (4.9%). Multivariable analysis showed factors for ciTBI were a diffuse headache, neurological deficits, signs of skull base fracture, Glasgow Coma Scale Score <13-14 after 2 h of observation, wound at the scalp, palpable skull fracture, dangerous mechanism, and vomiting 2 times or more. Loss of consciousness, amnesia, intoxication, and age were not predictors for ciTBI.

Conclusion

We found eight indicators to associate with ciTBI after MTBI which can be used to develop further clinical guidelines for computed tomography scans.

A critical comparison of clinical decision instruments for computed tomographic scanning in mild closed traumatic brain injury in adolescents and adults

STUDY OBJECTIVE

A number of clinical decision aids have been introduced to limit unnecessary computed tomographic scans in patients with mild traumatic brain injury. These aids differ in the risk factors they use to recommend a scan. We compare the instruments according to their sensitivity and specificity and recommend ones based on incremental benefit of correctly classifying patients as having surgical, nonsurgical, or no intracranial lesions.

METHODS

We performed a secondary analysis of prospectively collected database from 7,955 patients aged 10 years or older with mild traumatic brain injury to compare sensitivity and specificity of 6 common clinical decision strategies: the Canadian CT Head Rule, the Neurotraumatology Committee of the World Federation of Neurosurgical Societies, the New Orleans, the National Emergency X-Radiography Utilization Study II (NEXUS-II), the National Institute of Clinical Excellence guideline, and the Scandinavian Neurotrauma Committee guideline. Excluded from the database were patients for whom the history of trauma was unclear, the initial Glasgow Coma Scale score was less than 14, the injury was penetrating, vital signs were unstable, or who refused diagnostic tests. Patients revisiting the emergency department within 7 days were counted only once.

RESULTS

The percentage of scans that would have been required by applying each of the 6 aids were Canadian CT head rule (high risk only) 53%, Canadian (medium & high risk) 56%, the Neurotraumatology Committee of the World Federation of Neurosurgical Societies 56%, New Orleans 69%, NEXUS-II 56%, National Institute of Clinical Excellence 71%, and the Scandinavian 50%. The 6 decision aids' sensitivities for surgical hematomas could not be distinguished statistically (P>.05). Sensitivity was 100% (95% confidence interval [CI] 96% to 100%) for NEXUS-II, 98.1% (95% CI 93% to 100%) for National Institute of Clinical Excellence, and 99.1% (95% CI 94% to 100%) for the other 4 clinical decision instruments. Sensitivity for any intracranial lesion ranged from 95.7% (95% CI 93% to 97%) (Scandinavian) to 100% (95% CI 98% to 100%) (National Institute of Clinical Excellence). In contrast, specificities varied between 30.9% (95% CI 30% to 32%) (National Institute of Clinical Excellence) and 52.9% (95% CI 52% to 54) (Scandinavian).

CONCLUSION

NEXUS-II and the Scandinavian clinical decision aids displayed the best combination of sensitivity and specificity in this patient population. However, we cannot demonstrate that the higher sensitivity of NEXUS-II for surgical hematomas is statistically significant. Therefore, choosing which of the 2 clinical decision instruments to use must be based on decisionmakers' attitudes toward risk.