Emergency Department Shock Index Outperforms Prehospital and Delta Shock Indices at Predicting Outcomes of Trauma Patients: An Analysis of the Trauma Quality Improvement Program

Abstract

INTRODUCTION: Multiple shock indices, including prehospital, emergency department (ED), and Delta (ED shock index [SI] minus prehospital SI), have been developed to predict outcomes. We aimed to compare the predictive abilities of prehospital, ED, and Delta SIs for outcomes of polytrauma patients. METHODS: We analyzed the 2017 to 2018 ACS-TQIP including adult (18 years and older) trauma patients, and excluded patients who were transferred, and those with severe traumatic brain injury (head AIS greater than 3). Prehospital and ED SIs were categorized into 3 groups: SI 0.7 or less, SI less than 0.7 but 0.9 or greater, and SI greater than 0.9, and into 2 groups based on Delta SI less than 0.1 and 0.1 or greater. Outcomes were 24-hour and in-hospital mortality, 24-hour PRBC transfusions, ICU, and hospital length of stay. Predictive performances of SIs were evaluated by AUC-ROC. Paired-sample design was performed to compare AUC (95% CI among SIs for outcomes. RESULTS: A total of 750,407 adult trauma patients were identified. The mean age was 53 ± 21 years, 59% were male, mean prehospital and ED pulse rates were 90 ± 21 and 87 ± 21 bpm, respectively. Overall, 24-hour and in-hospital mortality were 1.2% and 2.5%, respectively. On multivariate analysis, all 3 SIs were independently associated with higher rates of 24-hour mortality, in-hospital mortality, blood product transfusion, and ICU and hospital length of stay (p < 0.001). ED SI was superior to prehospital SI, Delta SI, SBP, and HR alone (p < 0.001) for all outcome measures except for in-hospital length of stay (p > 0.05; Figure).Figure.: ED, emergency department; ISS, Injury Severity Score; LOS, length of stay; SI, shock index.CONCLUSION: All SIs outperformed SBP and HR alone at predicting worse outcomes of trauma patients, but ED SI outperformed both prehospital and Delta SIs across all injury severities. Trauma triage guidelines should prioritize ED SI to identify patients who may benefit from earlier trauma activations.