External validation of the revised lethal triad criteria for appropriate strategic decision making

Abstract

Background: The conventional lethal triad criteria for trauma are too specific for death and, thus, inappropriate as a standard for strategic decisions. Revised lethal triad criteria were previously proposed based on a multicenter study. Positive is defined as meeting one major criterion (fibrin/fibrinogen degradation product >90 μg/mL) or two minor criteria (base excess <-3 mEq/L or temperature <36°C). The aim of this study was to externally validate the revised lethal triad criteria by evaluating their predictive performance for 28-day mortality in severely injured patients.

Methods: Patients with trauma with an Injury Severity Score of ≥16, admitted to 25 Japanese institutions between April 2018 and March 2019, were included. The proportion of patients for whom the revised criteria could be calculated was assessed. The predictive accuracy of the conventional and revised lethal triad criteria was evaluated using the area under the receiver operating characteristic curve. Calibration plots were created to visually evaluate the agreement between predicted and observed 28-day mortality.

Results: Among 1,177 patients with severe blunt trauma, 125 (10.6%) died during hospitalization. The revised criteria could be calculated for 770 patients (65.4%). The conventional criteria predicted 28-day mortality with 2.8% sensitivity and 99.8% specificity, whereas the revised criteria showed 80.6% sensitivity and 64.4% specificity. The area under the receiver operating characteristic curves for the conventional and revised criteria were 0.68 and 0.77, respectively. Calibration plots showed high agreement between predicted and observed values for the revised criteria, indicating a well-calibrated model.

Conclusion: The revised lethal triad criteria demonstrated clinically sufficient sensitivity and appropriate specificity for predicting 28-day mortality in patients with severe trauma, suggesting their utility as indicators for adopting critical therapeutic strategies.

Level of evidence: Diagnostic Test or Criteria; Level IV.

Keywords: Trauma; damage control; lethal triad; validation.