The lethal triad: Past, present, and future

The post-traumatic "lethal triad" is a cornerstone theory in modern trauma care, and its evolution mirrors the paradigm shift in trauma medicine from empirical treatment to evidence-based precision medicine. This review traces the development of this theory, from the "bloody vicious cycle" first described in 1982, to the reconceptualization of acute traumatic coagulopathy in 2003, the establishment of damage control resuscitation strategies in 2007, and the revision of diagnostic criteria in 2016 to focus on fibrinolysis. Current clinical controversies primarily center on 3 aspects: (1) confusion regarding defining and differentiating between post-traumatic coagulation disorders, trauma-induced coagulopathy, and disseminated intravascular coagulation; (2) the predictive value of including hypocalcemia as a 4th element in a "lethal diamond" lacks evidence-based support; and (3) the lack of unified standards for intervention thresholds and correction strategies for hypothermia and acidosis. Furthermore, clinical practice issues, such as the superiority of whole blood versus component therapy, individualized viscoelastic hemostatic assay-guided treatment, and the role of life-support technologies such as extracorporeal membrane oxygenation, remain to be clarified. Future directions currently focus on 3 trends: (1) molecular phenotyping using metabolomic biomarkers and artificial intelligence algorithms for ultra-early identification and targeted hemostasis, (2) establishing a "lactate + base deficit" dual monitoring and real-time decision-making system integrating multi-source data, and (3) developing dynamic risk prediction models through multi-omics technologies to drive the transition from "reactive management" to "proactive prevention and treatment", all for advancing lethal triad-centered trauma care from reactive management to proactive prevention and treatment.