Development of injury risk models to guide CT evaluation in the emergency department after motor vehicle collisions

Utility of Abdominal Cross-Sectional Imaging in Motor Vehicle Accidents in an Inner City Trauma Center: A Retrospective Cohort Study

Background The use of computed tomography (CT) of the abdomen and pelvis following motor vehicle collisions (MVCs) as standard diagnostic evaluation is widely accepted. However, the incidence of positive findings is low, and it is unknown which features increase the risk of having abdominal injuries. Objectives The aim of this study is to identify risk factors on presentation that are associated with positive CT findings. Methods A retrospective review of patients from January 2020 to January 2023 in a level II urban trauma center who were in MVCs was performed. Standard ACS TQIP metrics were recorded, as well as vehicle speed, CT findings, and presenting characteristics. Low-speed MVCs were considered to be ≤25 mph and high-speed MVCs were considered to be >25 mph. Results In 4,444 trauma activations, there were 738 (16.6%) MVCs: 310 (42.0%) were low-speed, 160 (21.7%) were high-speed, and 268 (36.3%) were unknown-speed. Twenty-nine patients had positive CT findings. There was a significant difference in positive CT findings in low-speed versus high-speed MVCs (1.9% vs 5.9%, p < 0.05). Multivariate analysis for positive CT findings revealed that high-speed and unknown MVCs (ORadj 5.25 [95% CI 1.62-17.0] and ORadj 3.84 [1.34-11.0], respectively) were significant risk factors for positive CT findings. The number needed to scan for a positive CT finding was 53 patients for low speed, 17 for high speed, and 19 for unknown speed. Conclusion Our data indicate that a high-speed MVC is a discrete risk factor for positive CT findings. More research is needed to determine if there are other clinical factors to ultimately create a set of criteria for abdominal imaging in trauma.