Prognostic value of lactate levels and lactate clearance in sepsis and septic shock with initial hyperlactatemia: a retrospective cohort study according to the Sepsis-3 definitions

Abstract Background: This study evaluated the prognostic value of lactate levels and lactate clearance for the prediction of mortality in sepsis and septic shock patients.Methods: We performed a retrospective cohort study of sepsis and septic shock patients with initial lactate levels of ≥2 mmol/L. All patients met the Sepsis-3 definitions. The prognostic value of 6-hour lactate levels, lactate clearance, 6-hour lactate metrics (≥2 mmol/L), and lactate clearance metrics (<10%, <20%, and <30%) was evaluated. We compared the sensitivity and specificity between metrics.Results: Of the 363 sepsis and septic shock patients, 148 died (30-day mortality: 40.8%). Nonsurvivors had significantly higher 6-hour lactate levels and lower lactate clearance than those of survivors. Six-hour lactate levels and lactate clearance were associated with 30-day mortality after adjusting for potential confounders (odds ratio, 1.191 [95% confidence interval (CI), 1.097–1.294] and 0.989 [0.983–0.995], respectively). Six-hour lactate levels had better prognostic value than lactate clearance (area under the curve, 0.720 [95% CI, 0.670–0.765] vs. 0.656 [0.605–0.705]; p = 0.018). A 6-hour lactate level of ≥3.5 mmol/L and a lactate clearance of <24.4% were the optimal cutoff values in predicting the 30-day mortality. The prognostic value of 6-hour lactate metrics and lactate clearance metrics did not differ. Six-hour lactate levels (≥2 mmol/L) had the highest sensitivity (89.2%).Conclusions: Six-hour lactate levels proved to be more accurate in predicting 30-day mortality than lactate clearance.