Emergency Department Shock Index Outperforms Prehospital and Delta Shock Indices in Predicting Outcomes of Trauma Patients

Introduction: Multiple shock indices (SIs), including prehospital, emergency department (ED), and delta (ED SI - Prehospital SI) have been developed to predict outcomes among trauma patients. This study aims to compare the predictive abilities of these SIs for outcomes of polytrauma patients on a national level. Methods: This was a retrospective analysis of the American College of Surgeons Trauma Quality Improvement Program (2017-2018). We included adult (≥18 y) trauma patients and excluded patients who were transferred, had missing vital signs, and those with severe head injuries (Head-Abbreviated Injury Scale>3). Outcome measures were 24-h and in-hospital mortality, 24-h packed red blood cells transfusions, and intensive care unit and hospital length of stay. Predictive performances of these SIs were evaluated by the Area Under the Receiver Operating Characteristics for the entire study cohort and across all injury severities. Results: A total of 750,407 patients were identified. Meanstandard deviation age and lowest systolic blood pressure were 53 ± 21 y, and 81 ± 32 mmHg, respectively. Overall, 24-h and in-hospital mortality were 1.2% and 2.5%, respectively. On multivariable analysis, all three SIs were independently associated with higher rates of 24-h and in-hospital mortality, blood product requirements, intensive care unit and hospital length of stay (P < 0.001). ED SI was superior to prehospital and delta SIs (P < 0.001) for all outcomes. On subanalysis of patients with moderate injuries, severe injuries, and positive delta SI, the results remained the same. Conclusions: ED SI outperformed both prehospital and delta SIs across all injury severities. Trauma triage guidelines should prioritize ED SI in the risk stratification of trauma patients who may benefit from earlier and more intense trauma activations.