Imaging Evaluation in the Early Management of Severely Injured Patients.
Authors: Spering Christopher , Brauns Soehren Dirk , Bouillon Bertil , Seitz Mark-Tilmann , Jaeckle Katharina , Lehmann Wolfgang , Lefering Rolf , Dresing Klaus , Frosch Stephan 
Published: April 2021

Abstract
Introduction: The plain film chest x-ray in supine position (CXR) during the initial management of severely injured patients has almost lost its clinical relevance, since it has been challenged by extended focused assessment with sonography in trauma (eFAST) in early trauma management, due to its superiority in detecting a pneumo-/hematothorax. One of the last diagnostic fields in such setting of CXR is the mediastinal vascular injury. These injuries are rare yet life-threatening events. The most easily accessible diagnostic tool to identify these patients would be CXR as it is still one of the standard diagnostic tools in the early assessment of severely injured patients with significant thoracic trauma (Abbreviated Injury Scale, AIS ≥3). This study evaluates the role of early CXR in the Trauma Resuscitation Unit (TRU) in the last diagnostic field where eFAST cannot provide an answer: detecting mediastinal vascular injury in severely injured patients.Method: This retrospective, observational, single-centre study included all primary blunt trauma patients of a 24 months time period, that had been admitted to the TRU. Mediastinal/chest (M/C) ratio measurements were taken from CXRs at three defined levels of the mediastinum. The accuracy of the CXR findings were compared to whole-body computed tomography scans (WBCT) and therapeutic consequences were observed. Additionally a 15 years (2005–2019) time period out of the TraumaRegister DGU® was evaluated regarding usage of eFAST, CXR und WBCT in Level-1, -2, and − 3 Trauma Centres in Germany.Results: A total of 267 patients showed a significant blunt thoracic trauma (27 with mediastinal vascular injury (VThx)). The initial CXR in a supine position was unreliable for detecting mediastinal vascular injury. The sensitivity and specificity at different thresholds of maximum M/C ratio (2.0–3.0) were not clinically acceptable. The aortic contour and haemato- and pneumothorax were not reliably detected in the initial CXRs. No significant differences in the cardiac silhouette were observed between patients with or without mediastinal vascular injury (mean cardiac width, 136.5 mm, p = 0.44). No therapeutic consequences were drawn after CXR in the study period. The data from the TR-DGU (N = 251,095) showed a continuous reduction of CXR from 75% (2005) to 25% (2019), while WBCT raised from 35% to a steady level of about 80%. This development was seen in all trauma hospitals almost simultaneously.Conclusion: In present guidelines, CXR remains an integral diagnostic element during early TRU management, although several prior publications show the superior role of eFAST. Our data support that in most cases, CXR is time consuming and provides no benefit during initial management of severely injured patients and might delay the use of WBCT. The trauma centres in Germany have already significantly reduced the usage of CXR in the TRU. We therefore recommend to revise current guidelines and emphasise eFAST and rapid diagnostic through WBCT if rapidly available.