Initial lactate levels versus lactate clearance for predicting mortality in sepsis: A prospective observational analytical study

Lactate is a useful prognostic marker, as its level increases in hypoxic tissue and/or during accelerated aerobic glycolysis due to excessive beta-adrenergic stimulation and decreased lactate clearance. The Surviving Sepsis Campaign Bundle 2018 Update suggested re-measurement of lactate within 2-4 hours so as to conduct/ help/administer /introduce lactate-guided resuscitation to reduce mortality due to sepsis. The aim of this study was to compare initial lactate levels and lactate clearance at 4 h of recognition of sepsis as mortality predictors in sepsis. It was a prospective study performed with ethical approval in a single tertiary care centre. Patients aged 18 years or older who were diagnosed with sepsis by the Sepsis-3 definition were included in the study while patients who were not admitted to the ICU were excluded Dropout criteria was death of pateints within 4 hours of recognition of sepsis. Baseline demographic data was obtained and subjects were treated with an hour-1 bundle and examined for initial lactate levels. At 4 hours, lactate was re-measured and patients were observed for 28 days then after Lactate clearance was calculated by the following formula: ([initial lactate - hour-4 lactate]/initial lactate) × 100. Of the 41 subjects included in the study; 27 died (28-day mortality --65.9%). Age, sex, diagnosis of the patient and Charlson's Comorbidities scores between survivors and non-survivors showed no significant differences. Non-survivors had higher Sequential (sepsis-related) Organ Function Assessment (SOFA) scores (11.41±3.46 versus 8.77±2.92; p=0.02). Initial lactate levels and lactate clearance did not differ in prognostic value (AUC 0.67 versus 0.5; p=0.086), but initial lactate levels of >2 mmol/L had the greatest sensitivity (81.5%). Initial lactate level and lactate clearance did not differ in predicting mortality in patients with sepsis.