The following is a summary of “Association between early lactate-related variables and 6-month neurological outcome in out-of-hospital cardiac arrest patients,” published in the April 2024 issue of Emergency Medicine by Choi, et al.

The role of lactate measurement in predicting outcomes for out-of-hospital cardiac arrest (OHCA) survivors remains debated. For a study, researchers sought to investigate the association between early lactate-related variables, OHCA characteristics, and long-term neurological outcomes.

They analyzed patients with OHCA who underwent targeted temperature management and had lactate levels measured at 0, 12, and 24 hours post-return of spontaneous circulation. Lactate clearance and time-weighted cumulative lactate (TWCL) were calculated to represent lactate kinetics. They assessed the predictive value of lactate-related variables for 6-month poor outcome (Cerebral Performance Category 3–5) using the area under the receiver operating characteristic curve (AUC) and adjusted odds ratios (AORs). Interaction between lactate variables and OHCA characteristics was evaluated through a multivariable logistic model with interaction terms and subgroup analysis.

The study included 347 patients with OHCA. After adjustment, higher lactate levels at all time points were associated with poor outcomes (AOR 1.10 [95% CI, 1.03–1.18], AOR 1.15 [95% CI, 1.02–1.29], and AOR 1.36 [95% CI, 1.15–1.60], respectively). TWCL was the sole lactate kinetics variable linked to poor outcome (AOR 1.29 [95% CI, 1.12–1.49]). Several interactions between lactate-related variables and OHCA characteristics were identified. Notably, TWCL had excellent predictive value for noncardiac etiology (AUC 0.92 [95% CI, 0.86–0.96]) but only moderate value for cardiac etiology (AUC 0.69 [95% CI, 0.62–0.75]).

Early lactate levels, particularly at 24 hours, and TWCL independently predicted neurological outcomes, while lactate clearance did not. The prognostic performance of lactate-related variables varied based on OHCA characteristics.

Reference: sciencedirect.com/science/article/abs/pii/S0735675724000068