Is There a Need for Abdominal CT Scan in Trauma Patients With a Low-Risk Mechanism of Injury and Normal Vital Signs?

Abstract

Background Clinically significant injuries are often missed in trauma patients with low-risk mechanisms of injury and lack of "red flags," such as abnormal vital signs. The purpose of this retrospective analysis was to evaluate the efficacy of computed axial tomography (CT) for identifying occult injuries in a high-volume trauma center. Methods Records from our institutional trauma registry were retrospectively extracted, examining encounters from January 2015 to October 2019. Those patients between the ages of 18 and 65 who were referred to the trauma team with a CT scan of the abdomen and had low-risk mechanisms of injury, a Glasgow Coma Scale (GCS) score of 15, and normal vital signs at presentation were included. Patients in the lowest trauma categorization (Level Three, Consult) met the study definition for the low-risk mechanism of injury. Demographic and clinical data were abstracted for all patients. For this analysis, patients were divided into two groups based on age (18 - 40 years or 40 - 65 years). Injuries found on CT, their clinical significance, and the likelihood of being missed without CT were determined. Results Of 2,103 blunt trauma patients that received a CT scan of the abdomen from January 2015 to October 2019, 134/2,103 (6.4%) met the inclusion criteria (mean age: 44.6 years; 72.3% male). Patients between the ages of 40 and 65 years comprised 61.2% (82/134) of the study population. Of the included patients, 17.2% (23/134) had at least one acute traumatic injury identified after CT imaging of the torso. Occult injuries found on CT included rib fracture with associated lung injuries (10/23, 43.5%), splenic laceration (4/23, 17.4%), liver laceration (3/23, 13.0%), gluteal hematoma with active bleeding (1/23, 4.3%), sternal fractures (3/23, 13.0%), and thoracic or lumbar spine fractures (2/23, 8.7%). An independent review of the medical records determined that 9.0% (12/134) of these patients had traumatic injuries that would have been missed based on clinical examination without CT. Conclusions Based on our experience, utilizing CT imaging of at least the abdomen as a routine screening measure for all trauma consults - even low-risk patients with normal vital signs - can rapidly and accurately identify clinically significant injuries that would have been otherwise missed in a notable portion of the population.

Keywords: lung injury; non-penetrating wounds; retrospective studies; trauma centers; x-ray computed tomography.

Figure 1. Criteria for categorization of patients based on trauma level at presentation

This criterion for trauma triage is based on the American College of Surgeons’ Resources for Optimal Care of the Injured Patient and adapted based on our institutional experience [15]. The receiving staff categorizes the patient based on their highest level of symptoms so that an appropriate team is available for care; patients lacking any Level One or Level Two symptoms are triaged to Level Three. BSA: body surface area; HR: heart rate; RR: respiration rate; TBSA, total body surface area