Prehospital point-of-care lactate for identification of severe injury in trauma team-activated patients: a prospective multicenter cohort study.

backgroundAccurate prehospital trauma triage remains challenging despite structured activation criteria, particularly in patients without overt physiologic instability. Prehospital point-of-care lactate has been proposed as a physiologic adjunct to support early identification of severely injured patients. This prospective multicenter cohort study evaluated the association between prehospital lactate and injury severity in trauma team-activated patients within a structured guideline-based trauma system.

methodsThis prospective observational multicenter cohort study included adult trauma patients transported by emergency medical services to three Level I trauma centers and managed in the trauma room following trauma team activation (TTA). Prehospital lactate was measured by capillary earlobe sampling before or during transport and was not used for clinical decision-making. The primary outcome was severe injury, defined as Injury Severity Score (ISS) ≥16. Secondary outcomes were Abbreviated Injury Scale (AIS) ≥4 in at least one body region and intensive care unit (ICU) admission > 24 hours. Diagnostic performance was assessed using receiver operating characteristic (ROC) analysis and predefined lactate thresholds of ≥2 mmol/L and ≥4 mmol/L.

resultsA total of 108 patients were included, of whom 26 (24.1%) had ISS ≥ 16. Prehospital lactate levels were higher in severely injured than in non-severely injured patients. For prediction of ISS ≥ 16, prehospital lactate yielded an area under the curve (AUC) of 0.636 (95% CI 0.509-0.763). At a threshold of ≥2 mmol/L, sensitivity was 80.7%, whereas specificity was limited. Higher thresholds increased specificity at the expense of sensitivity. Similarly limited discriminatory performance was observed for AIS ≥ 4 and ICU admission > 24 hours.

conclusionIn trauma team-activated patients within a structured guideline-based trauma system, prehospital lactate was associated with severe injury but showed limited discriminatory performance for ISS-defined severe injury. Based on these findings, prehospital lactate does not appear suitable as a stand-alone trauma triage parameter in this setting but may provide complementary physiologic information when integrated into multimodal prehospital assessment strategies alongside established trauma team activation criteria. Future adequately powered prospective studies should evaluate its incremental value in combination with established physiologic parameters and focus on clinically proximal outcomes such as trauma team activation, hemorrhage control procedures, transfusion requirements, or other early life-saving interventions.