[Analysis of correlation between inflammatory parameters and severity of sepsis caused by bacterial bloodstream...

To discuss the differences of inflammatory parameters such as procalcitonin (PCT), C-reactive protein (CRP), endotoxin, white blood cell (WBC), neutrophil ratio (Neut%) in blood of septic patients caused by bacterial bloodstream infection, and their correlation with the severity of disease.

292 septic patients with positive blood culture were enrolled in Beijing Shijitan Hospital Affiliated to Capital Medical University from February 2012 to March 2015, and their gender, age, acute physiology and chronic health evaluation II (APACHEII) score, bacterial species and other general information were retrospectively collected. The differences in inflammatory parameters (PCT, CRP, endotoxin, WBC, Neut%) in septic patients caused by bacterial bloodstream infection were compared, their correlations with APACHEII scores within 24 hours were analyzed, and their diagnostic efficacies were also analyzed.

(1) It was shown by Pearson correlation coefficients that positively statistical correlation was found between PCT (r=0.638), CRP (r=0.620), endotoxin (r=0.284), WBC (r=0.209) and APACHE II score (all P=0.000) in bacterial bloodstream infective patients (n=292), and positively statistical correlation was found between PCT (r=0.626), CRP (r=0.616), Neut% (r=0.297) and APACHE II score (all P<0.01 ) in Gram positive bacterial (G+) group (n=86), and positively statistical correlation was shown between PCT (r=0.631), CRP (r=0.616), endotoxin (r=0.301), WBC (r=0.226 ) and APACHE II score (all P<0.01) in Gram negative bacterial (G-) group (n=206). (2) It was shown that PCT and CRP of both G+/G- bacterial severe sepsis and septic shock subgroup were significantly higher than those of sepsis subgroup, respectively [G+ group: PCT (μg/L):0.92 (0.38, 4.75) vs. 0.43 (0.22, 1.00), CRP (mg/L): 118.45±62.60 vs. 57.97±32.41; G- group: PCT (μg/L):6.92 (1.94, 25.90) vs. 1.28 (0.27, 4.12), CRP (mg/L): 130.99±60.18 vs. 49.18±26.87, all P<0.01], and the endotoxin and WBC in G- bacterial severe sepsis and septic shock subgroup were significantly higher than those of sepsis subgroup [endotoxin (ng/L): 19.40 (9.62, 33.87) vs. 10.00 (5.00, 18.52), WBC (×10(9)/L): 12.13±6.72 vs. 9.61±5.01, both P<0.01]. The PCT and endotoxin in G- bacterial severe sepsis and septic shock subgroup were significantly higher than those in G+ severe sepsis and septic shock subgroup [PCT (μg/L): 6.92 (1.94, 25.90) vs. 0.92 (0.38, 4.75), endotoxin (ng/L): 19.40 (9.62, 33.87) vs. 2.56 (1.11, 4.01), both P<0.01]. (3) The diagnostic efficacy of inflammatory parameters for severe sepsis and septic shock subgroup were: PCT area under receiver operating characteristic (ROC) curve (AUC)=0.683, the cut-off point=0.55 μg/L, sensitivity 63.2%, specificity 69.0%; CRP AUC=0.802, the cut-off point=92.25 mg/L, sensitivity 73.7%, specificity 86.2%; WBC AUC=0.614, the cut-off point=7.35×10(9)/L, sensitivity 75.4%, specificity 48.3%; Neut% AUC=0.622, the cut-off point=0.882, sensitivity 43.9%, specificity 79.3% in G+ group. At the same time, it was shown that PCT AUC=0.780, the cut-off point=6.80 μg/L, sensitivity 51.0%, specificity 93.9%; CRP AUC=0.907, the cut-off point=90.10 mg/L, sensitivity 73.2%, specificity 95.9%; endotoxin AUC=0.694, the cut-off point=17.54 ng/L, sensitivity 57.3%, specificity 75.5%; WBC AUC=0.611, the cut-off point=10.54×10(9)/L, sensitivity 54.1%, specificity 69.4%; Neut% AUC=0.621, the cut-off point=0.843, sensitivity 65.6%, specificity 61.2% in G- group.

The plasma PCT and CRP have the best correlation between inflammatory parameters and severity of disease in bloodstream infective sepsis patients. CRP has the best diagnostic effect in severe sepsis/septic shock patients with bloodstream infection.