The effects of blood lactate level on mortality in patients developing sepsis in intensive care unit

Aim: Sepsis is a serious condition with high mortality and morbidity in intensive care units (ICUs). Mortality decreases with early and appropriate antimicrobial treatment. We aimed to investigate the relationship between lactate levels and mortality in the ICU of our hospital. Methods: Patient records > 18, hospitalized in the ICU of Meram State Hospital between January 2022 and January 2024, were retrospectively examined. All patients microbiologically confirmed to have positive blood culture results and diagnosed sepsis were included in the study. Age on admission, gender, diagnoses at hospitalization, Apache II, length of stay, and mortality in ICU were obtained from patients’ medical records. In the presence of suspicion of sepsis in a patient hospitalized in intensive care and in the first 72 hours after antibiotic treatment, the lactate level was recorded. Lactate clearance was defined as the percent decrease in lactate from ICU department presentation to hour 72. Mortality rates within the first 28 days were recorded. Lactate levels were compared in patients with and without mortality. The value of lactate in predicting mortality was evaluated statistically. Results: Of 56 patients included in the study, whose diagnoses of sepsis were microbiologically proven, 38 (67.9%) died. The area under a receiver operating characteristic (ROC) curve Area under curve (AUC) of lactate in predicting mortality was 0.738 [95% confidence interval (CI): 0.590 –0.886, (p=0.004)]. Threshold lactate value for mortality was 1.7 mmol/L (sensitivity: 73.7%, specificity: 61.1%). While lactate levels, lactate clearance, length of hospital stay, Acute Physiologic and Chronic Health Evaluation (APACHE II) score were statistically significant between sepsis patients with and without mortality (p=0,004, p = 0.03 p= 0,00 p=0.003). Baseline lactate was in survivors 2.05±1.37 and in nonsurvivors 1.33±0.98 mmol/L. Survivors compared with nonsurvivors had a lactate clearance of 48.2 ± 24.4 vs. 22.06 ± %, respectively (p = 0.007). It showed lactate clearance to have a significant relationship with mortality (p = 0.03). Conclusion: Here, we found that lactate level and, lactate clearance may be a significant place in the early treatment and follow-up of sepsis patients in ICUs.