Lactate clearance, and lactate in predicting mortality in patients with severe trauma

Purpose : Lactate Clearance (LC) has recently emerged as a therapeutic goal to be achieved in the first hours of septic shock’s resuscitation. In severe trauma patients, there is an urgent need to rapidly assess initial management’s quality and to diagnose occult hypoperfusion at its early stages. The aim of this study was to assess lactatemia and lactate clearance as predictors of mortality in severe trauma. Methods: This was a retrospective, observational and analytical study. We included all adults having severe trauma and who required intensive care and who had a lactatemia measurement at admission (LH0), at the 4th hour (LH4), and the 12th hour (LH12). LC was calculated (%/h) between admission and the 4 ^th hour (LC H0-H4), admission and the 12 ^th hour (LC H0-H12) and the4 ^th and the 12 ^th hour (LC H4-H12). Our primary endpoint was in-hospital mortality. To assess the association of lactatemia and LC with mortality, we analyzed the ROC curves and carried out univariate and multivariate analysis in logistic regression. Results: A total of 318 patients were included. LC H0-H12 (AUC = 0.753) was a better parameter than LH0 (AUC = 0.735), LH4 (AUC = 0.711), LH12 (AUC = 0.643), LC H0-H4 (AUC = 0.688), LC H4-H12 (AUC = 0.667) to predict in-hospital mortality. The cut-off was -2.92% with a sensitivity = 76.1% and a specificity = 63.6%. The in-hospital mortality rate increased from 21.3% for a negative LC H0-H12 to more than 50% for positive values. LC H0-H12 also performed better than RTS (AUC=0.724), MGAP (AUC=0.735) and ISS (AUC=0.729). The addition of LC H0-H12 and LH0 to these scores improved their quality as well as that of TRISS. Likewise, LC H0-H12 was able to predict early mortality (AUC=0.798), an ISS> 15 (AUC=0.602) and hemorrhagic shock (AUC=0.647). Finally, we could develop a clinical-biological prognostic score including LC H0-H12, pH, PT, Glasgow coma scale and age. Conclusion: LC H0-H12 measurement is a relevant tool that should be incorporated into treatment regimens as part of a "Lactate clearance goal-directed therapy” in severe trauma.