Efficacy of neutrophil-lymphocyte ratio, serum lactate, and lactate clearance in predicting mortality in patients with sepsis admitted to a tertiary care hospital: A prospective observational study

Objectives: Neutrophil-to-lymphocyte ratio (NLR), serum lactate, and lactate clearance (LC) are frequently used for rapid bedside assessment of the severity of sepsis. This study aimed to evaluate the individual and combined efficacy of NLR, serum lactate, and LC, measured in the emergency department (ED), in predicting 28-day mortality. Materials and Methods: This was a single-center and prospective observational study, conducted in a tertiary care hospital (CTRI/2018/08/015371). The study included adult patients aged 18–80 years, admitted to the ED with sepsis. Along with baseline demographic and hemodynamic variables, NLR, serum lactate, and LC were collected. Patients were followed until death or for a maximum of 28 days. Results: Out of 50 patients, 33 survived (66%). Non-survivors had lower systolic, diastolic, mean blood pressure, lower LC, tachycardia, high sequential organ failure assessment score, vasopressors requirement, mechanical ventilation requirement, and high NLR. NLR (≥11.13) was best correlated with 28-day mortality [area under receiver operating curve (AUROC) 0.87], followed by initial lactate (≥3.3, AUROC 0.77) and LC (≤17.07%, AUROC 0.73). Multivariate logistic regression revealed that NLR and LC were independent predictors of mortality, with weak correlation between them. However, their combination did not perform better (AUROC 0.82) than individual markers. Conclusion: NLR and LC can be used with moderate certainty in predicting 28-day mortality.