Implementing the canadian computed tomography head rule in an urban united states emergency department: A retrospective chart review

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Conference Proceeding

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Academic emergency medicine


Background and Objectives: The Canadian CT Head Rule (CCHR) is a validated decision rule which safely identifies minor head injury patients for whom CT is not necessary. The CCHR's acceptance in US EDs is variable with the less specific New Orleans criteria still favored by ACEP guidelines. In this study, we report the incidence of intracranial injuries after adoption of the CCHR as part of the Michigan Emergency Department Improvement Collaborative (MEDIC), a quality improvement network of unaffiliated hospitals sharing a clinical data registry within a structured implementation and incentive program.

Methods: The study occurred in an urban level 1 trauma center, with patient volumes of 100,000 annually. Utilizing the MEDIC database, we identified and reviewed all patients receiving head CT (HCT) between July 2016 and December 2018. A trained abstractor retrospectively reviewed all charts to determine if the CT was appropriate based on the CCHR. HCT with findings of acute injuries were independently reviewed by two radiologists to determine clinical significance based on those outlined in the in original CCHR study. Analysis included descriptive and univariate statistics.

Results: 7591 head injuries were documented during the study period, of which 3428 (45%) were eligible for review-significant exclusions included GCS <15 and intoxication for pragmatic purposes of chart review. Among eligible cases, there were 1775 (52%) patients who received a head CT. 665 (37%) of HCTs performed were deemed appropriate (met at least one of the CCHR criteria) and 1110 (63%) were deemed inappropriate (met none of the CCHR criteria). Those in the appropriate group were significantly older, had greater acuity scores, and higher admission rates. Of those receiving HCT, 3.7% (66) of patients were found to have clinically significant intracranial injury: 6.0% (40) among the appropriate group and 2.4% (26) among the inappropriate group (p<0.001). Any intracranial bleeding was found in 49 (7.3%) patients of the appropriate group and 25 (2.3%) in the inappropriate group and (p<0.001).

Conclusion: Based on our findings of low rates of intracranial bleeding in patients not meeting CCHR criteria, we believe that there is significant room for safe reduction in CT utilization rates. Further studies should be conducted on how implementation of the CCHR affects overall CT utilization rates and barriers to its use.



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