Lactate and pH as Predictors of In-Hospital Mortality in Extracorporeal Cardiopulmonary Resuscitation: A Single-Center Retrospective Study.
Abstract
Objectives
Extracorporeal cardiopulmonary resuscitation (ECPR) is increasingly used for patients with refractory cardiac arrest, yet optimal criteria for patient selection remain poorly understood. Precannulation lactate and pH values are prognostic markers, but given the wide ranges in existing literature, there is no consensus on threshold values that optimally stratify risk. This study aims to evaluate individual and combined prognostic values of precannulation lactate and pH in predicting hospital mortality.
Design
Retrospective cohort study.
Setting
Single, quaternary academic center.
Participants
Adult patients undergoing ECPR between September 2011 and April 2025 (n = 484).
Interventions
None.
Measurements
AND MAIN
Results
Pre- and postcannulation lactate and pH values were retrospectively identified. Logistic regression‒assessed associations between lactate and pH and hospital mortality, receiver operating characteristic curves, and area under the curve values were calculated. Optimal cut-off values for lactate and pH were calculated using the Youden index in receiver operating characteristic analyses. Median lactate was 8.7 mmol/L (IQR 4.1-12.3), and median pH was 7.23 (IQR 7.09-7.34). In-hospital mortality was 62.4%. Non-survivors had significantly higher median lactate (9.3 v 7.3, p < .001) and lower median pH (7.2 v 7.27, p < .001) values. In multivariable logistic regressions, lactate (OR 1.13 per mmol/L, 95% CI 1.05-1.22) and pH (OR 0.61 per 0.1 unit, 95% CI 0.47-0.76) were each independently associated with mortality. However, in models including both variables, pH remained a significant predictor of mortality, whereas lactate did not. Optimal cut points were 10.85 mmol/L for lactate and 7.2 for pH.
Conclusion
These findings support the inclusion of lactate and pH in a cumulative, multifactorial risk stratification framework to inform real-time prognostication and patient selection for ECPR on an individual programmatic basis.