Is Lactate Clearance Useful in Predicting Cardiopulmonary Resuscitation Outcome and 48-Hour Mortality?

Objective: To investigate the predictive value of lactate clearance (ΔL) in witnessed cardiac arrest patients in the emergency department (ED) at two time points: Cardiopulmonary resuscitation (CPR) outcome and 48-hour mortality.

Study Design: Observational study. Place and Duration of the Study: Department of Emergency Medicine, Duzce University, Duzce, Turkiye, from July 1 to December 31, 2023.

Methodology: Patients aged 18 years and older presenting with cardiac arrest in the ED, whose relatives signed the informed consent form, were included. Out-of-hospital cardiac arrest, trauma-related cardiac arrest, major bleeding, and known malignancy were excluded from the study. All patients who met the criteria were included. All data were recorded prospectively. Receiver operating characteristic (ROC) analysis and risk analysis were performed for lactate clearance (ΔL) and 20-minut Results: The predictive power of ΔL at 10 minutes (ΔL 0-10), 20 minutes (ΔL0-20), and between 10 and 20 minutes (ΔL10-20) was found to be significantly high for both the likelihood of no-ROSC (return of spontaneous circulation) and 48-hour mortality across all patients. The AUC values for ΔL at first 10 minutes, 20 minutes, and within 10-20 minutes were 0.991, 0.997, and 0.944, respectively for the no-ROSC group, and 0.942, 0.947, and 0.882, respectively for 48-hour mortality in the ROSC group. ROSC was not achieved in any patient with ΔL0-20 value of ≤-0.15. ΔL below the calculated thresholds increased the risk of not achieving ROSC and 48-hour mortality by tenfold.

Conclusion: ΔL during CPR is a useful tool to predict the outcome of CPR and 48-hour mortality. The ΔL0-20 value was evaluated as a valuable parameter that can be used after the 20th minute of CPR when deciding whether to continue or terminate CPR.

Key Words: Emergency department, In-hospital cardiac arrest, Lactate clearance, Mortality, CPR outcome.