Neutrophil‐lymphocyte ratio and plasma lactate predict 28‐day mortality in patients with sepsis

Objective The predictive potential of the neutrophil‐to‐lymphocyte ratio (NLR) and plasma lactate was investigated in regard to the prognosis of patients with sepsis. Methods Sixty‐three nonsurgical and nontrauma adult patients with sepsis admitted to the intensive care unit (ICU) from September 2016 to October 2018 were consecutively included in the study. In addition, healthy subjects were assigned to a control group. Neutrophil and lymphocyte counts were evaluated via a complete blood count. Plasma lactate, procalcitonin (PCT), and C‐reactive protein (CRP) levels were measured. The main outcome was 28‐day mortality. Results Neutrophil‐to‐lymphocyte ratio and plasma lactate levels of the patients were significantly higher than those of control subjects: 19.44 (14.3‐34.53) vs 14.09 (8.17‐28.99), P  = 0.049; and 3.7 (3‐6.6) vs 2.72 (2.13‐4.3) ng/mL, P  = 0.008, respectively. There were no statistical differences in the concentrations of PCT and CRP between nonsurvivors and survivors: 6.1 (3.43‐33.59) vs 9.43 (4.24‐37.68) ng/mL, P  = 0.44; and 108 (77.8‐153) vs 114.5 (71.43‐162) ng/mL, P  = 0.672, respectively. With an optimal cutoff of 14.08, the sensitivity and specificity of NLR for prediction of 28‐day mortality were 78.3% and 50%, respectively. And the sensitivity and specificity of plasma lactate level to predict 28‐day mortality, at an optimal cutoff value of 2.99 mmol/L, were 82.6% and 55%, respectively. Conclusions Neutrophil‐to‐lymphocyte ratio and plasma lactate were associated with poor outcomes in patients with sepsis and predicted mortality.