Neutrophil-to-lymphocyte Ratio as a Marker for Diagnosis and Prognostication of Sepsis

Exploring the ideal marker for early diagnosis and prognosis of sepsis is crucial due to limitations of available sepsis indicators. Hence, we aimed to evaluate the neutrophil-to-lymphocyte ratio (NLR) as a diagnostic and prognostic marker of sepsis. This prospective case-control study was conducted at a tertiary care teaching public hospital. NLR values among cases and controls were compared for diagnosis. Among cases, serial trends in NLR values, outcome (survival or death), and various parameters such as Sequential Organ Failure Assessment (SOFA) score, duration of intensive care unit (ICU) stay, etc. were compared between survivors and nonsurvivors for prognosis. Analysis was performed using MS Excel and PSPP version 1.0.1. A total of 120 patients (60 cases and 60 controls) were analyzed. The NLR among cases was significantly higher (p = 1.31 × 10-16) than in controls. Using binary logistic regression, a high NLR was found to be a statistically significant predictor of sepsis category (p = 2.25 × 10-5). The association of various variables among survivors and nonsurvivors of cases showed statistically significant differences: NLR (p = 5.29 × 10-5), mean = 13.27, interquartile range (IQR) = 5.90, z-value = -4.042), C-reactive protein (CRP) (p = 4.80 × 10-7), mean = 74.40, IQR = 21.30, z-value = -5.034), D-dimer (p = 4.32 × 10-8), mean = 7.09, IQR = 0.88, z-value = -5.477), SOFA score (p = 0.00118, mean = 8.50, IQR = 3.00, z-value = -3.244), and duration of hospital stay (p = 0.03578, mean = 13.45, IQR = 8.00, z-value = -2.099). The NLR emerges as a valuable marker for both diagnosis and prognosis in sepsis. Elevated NLR levels aid in diagnosing sepsis at very early stages, and the trend of NLR demonstrates a dynamic course throughout the disease process. Persistently elevated NLR and high NLR values correlate with poor outcomes in sepsis. Additionally, NLR can be correlated with other prognostic markers of sepsis and mortality. Therefore, we recommend the utilization of NLR as a quick, easy, and cost-effective marker for both early diagnosis and regular prognostication of sepsis.