Predictive Value of Procalcitonin and Neutrophil-to-Lymphocyte Ratio Variations for Bloodstream Infection with Septic Shock

BACKGROUND: Little is known of neutrophil-to-lymphocyte ratio (NLR) variations in septic shock. Hence, the predictive value of procalcitonin (PCT) and NLR variations for septic shock in bloodstream infection were explored. MATERIAL/METHODS: We analyzed 146 patients with bloodstream infection admitted to the Intensive Care Unit (ICU) of the First Affiliated Hospital of Anhui Medical University from October 2016 to May 2020. PCT and NLR were evaluated at 0 and 48 h after admission, and their variations (ΔPCT and ΔNLR) were calculated. The patients were divided into a shock group (n=80) and a non-shock group (n=66) and a gram-positive cocci group (n=69) and a gram-negative bacilli group (n=77). The predictive value of ΔPCT and ΔNLR was compared among groups. RESULTS: AUROC of NLR0h (0.756) higher than PCT0h (0.743).ΔPCT (0.561 vs 0.301) and ΔNLR (0.609 vs 0.361) were significantly higher in the shock group than in the non-shock group (P<0.05). No significant difference was seen in ΔPCT and ΔNLR in the gram-positive cocci infection group. However, the gram-negative bacilli infection group showed a significant difference in ΔPCT (0.606 vs 0.312) and ΔNLR (0.872 vs 0.508) between the shock and non-shock groups (P<0.05). ΔPCT+ΔNLR showed the best area under the curve (0.937), with a high sensitivity (78.80%) and specificity (90.80%), for predicting septic shock. CONCLUSIONS: The prediction efficiency of initial NLR is higher than that of PCT. ΔPCT+ΔNLR best predicted septic shock in patients with bloodstream infections, with better accuracy for gram-negative infections.