摘要Objective: To determine and compare the diagnostic efficiency of various biomarkers [C-reactive protein, neutrophil percentage, neutrophil-lymphocyte ratio (NLCR), lactate, procalcitonin, blood culture] in the identification of septic patients in emergency department (ED), and to assess the predictive value of combination of markers. Methods: This was a prospective, single centre study conducted in the ED of an urban, tertiary care hospital. We included patients who were admitted to the ED with symptoms of a possible infection. Blood cultures and serum measurement of the biomarkers were collected from 131 patients. Patients were determined to be septic or non-septic, based on the systemic inflammatory response syndrome criteria and the diagnosis was made at the ED. Sensitivity, specificity, positive predictive value, negative predictive value and area under curves (AUC) were calculated. Results: A total of 126 patients, 61 with sepsis and 65 without sepsis were eventually included in the study. Neutrophil to lymphocyte ratio displayed the highest accuracy in diagnosing sepsis (AUC 0.735, 95% CI=0648-0.822, P＜0.001). The best combination of markers in predicting sepsis was NLCR and white blood cell (AUC: 0.801, 95% CI=0.724-0.878, P＜0.001). Conclusions: The results of this small study showed that NLCR outperforms other markers in diagnosing sepsis in ED. It is readily available, cost efficient, non invasive and independent. It may be insufficient to rely on this single marker to diagnose sepsis, so some other diagnostic utilities should be taken into account as one part of the overall assessment. Our study also showed that combination of NLCR and white blood cell provides the highest diagnostic accuracy. More large scale studies across different population groups will be needed to confirm this finding.