344 Prior CT Imaging History for Patients Who Undergo PAN CT for Acute Traumatic Injury and are Discharged Home from the Emergency Department

Abstract

Recurrent CT imaging is believed to significantly increase lifetime malignancy risk. We previously reported that high acuity, admitted trauma patients who received a PAN (full body) CT in the ED had a history of prior CT imaging in 14% of cases. The primary objective of this study was to determine the CT imaging history for trauma patients who received a PAN CT but were ultimately deemed safe for discharge directly home from the ED. This was an observational cohort study of consecutive ED trauma patients at an inner-city, ED (level 2 trauma center) between 3/25/16-10/25/16. Eligible patients were prospectively identified who received a PAN CT ordered at the discretion of the treating physician but were later discharged directly from the ED to home. Authors conducted a structured review of electronic radiology records within our 6 affiliated hospital system to identify instances of prior CT. The hospitals comprise 192,073 annual ED visits (70.6% of all ED visits within a 12-county region). Categorical data analyzed by chi-square; 95% CIs calculated. Continuous data analyzed by t-tests. Primary outcome parameter was to determine the proportion of patients in the study group who had prior CTs. Multivariate logistic regression was utilized to examine relationship between positive prior CT history and patient characteristics/mechanism of injury. There were 165 patients in the study group; mean age 39+/-16 years, 38% were female, 64% Hispanic. The most common mechanism of injury was motor vehicle crash (66%). 25% (95% CI=19-32%) of the patients had at least one prior CT. The most common prior studies performed were: CT abdomen and pelvis (13%; 95% CI=8.4-19%), CT head (9.1%; 95% CI=5.5-16%), and CT face (6.7; 95% CI=3.6-12%), and CT chest (1.8%; 95% CI=0-5.4%). Multivariate logistic regression revealed that increasing age (p=0.03; OR=1.0; 1.0-1.1) was weakly associated with positive prior CT history but other patient characteristics including mechanism were not. We found that there was a positive history for prior CT for 25% of trauma patients who received a PAN CT but were discharged from the ED to home. Our results should encourage clinicians to evaluate prior CT history (patient report/records) and consider shared decisionmaking/use of selective CT algorithms in cases for which pretest assessment for risk of serious injury is relatively low.