Diagnostic performance of prehospital EFAST in predicting CT scan injuries in severe trauma patients: a multicenter cohort study

BackgroundThe early mortality of trauma patients, mainly from hemorrhagic shock, raises interest in detecting the presence of non-exteriorized bleeding. Intra-hospital EFAST (Extended Focused Assessment with Sonography for Trauma) has demonstrated its utility in the assessment and management of severe trauma patients (STP). However, there is a lack of data regarding the diagnostic performance of prehospital EFAST (pEFAST). The main objective of our study was to evaluate the pEFAST performance to predict a positive CT scan in STP.MethodsThis was a retrospective, multicenter, database-driven study. All severe trauma patients managed by a prehospital medical team were included. The results of pEFAST were compared with the admission CT scan.ResultsData from 495 patients were included. The pEFAST had sensitivity of 27% (95% CI 22; 32) and specificity of 94% (95% CI 90; 97) for predicting the presence of a lesion on CT scan at hospital admission. The area under the curve (AUC) was 0.66 (95% CI 0.57; 0.63), the positive predictive value 84% (95% CI 75; 87), the negative predictive value was 51% (95% CI 44; 66), the positive likelihood ratio was 4.24 (95% CI 2.46; 7.3) and the negative likelihood ratio 0.78 (95% CI 0.72; 0.85).ConclusionPrehospital EFAST has an excellent specificity but a poor sensitivity for predicting a positive CT scan on hospital admission. We do not know whether this low sensitivity is secondary to the delay between the two examinations or to the poor performance of pEFAST. Therefore, a negative pEFAST should not be reassuring. A positive pEFAST is highly informative, as it predicts a lesion and enables hospital management to be prepared accordingly.