Dynamic lactate clearance within the first 48 hours predicts pressure injury during ECMO support: a longitudinal cohort study

Backgrounds: This study aimed to investigate the association between dynamic lactate clearance and the development of pressure injuries in adult patients undergoing extracorporeal membrane oxygenation (ECMO) support and to evaluate its incremental value for early risk prediction. Mehods: This was a retrospective longitudinal cohort study. A total of 317 adult patients receiving ECMO support were enrolled. Lactate concentrations were measured at ECMO initiation and at 6, 24, and 48 h thereafter. Lactate clearance rates were calculated for each corresponding time point. Multivariable logistic regression analysis was performed to identify independent risk factors for pressure injury development. The predictive performance of lactate clearance was assessed using receiver operating characteristic (ROC) curves, five-fold cross-validation, net reclassification improvement (NRI), and integrated discrimination improvement (IDI). Independent predictors of pressure injury included higher body mass index, elevated vasoactive-inotropic score, VA-ECMO mode, and concomitant renal replacement therapy. The baseline clinical model yielded an area under the curve (AUC) of 0.710. Incorporating lactate clearance significantly improved model discrimination, with AUCs increasing to 0.796, 0.825, and 0.899 for the 6-hour, 24-hour, and 48-hour models, respectively. Consistent enhancements in predictive accuracy were confirmed by cross-validation, NRI, and IDI analyses. Conclusions: Impaired lactate clearance is independently associated with pressure injury development in critically ill adults supported by ECMO. Dynamic monitoring of lactate clearance substantially enhances risk stratification beyond traditional clinical parameters.