白细胞、降钙素原和超敏C反应蛋白在超高龄重症患者血流感染的诊断预测价值

Predictive value of white blood cell, procalcitonin and high-sensitivity C-reactive protein for the bloodstream infection in the super-elderly critically-ill patients

目的比较白细胞(WBC)、降钙素原(PCT)及超敏C反应蛋白(hs-CRP)在超高龄重症患者中对血流感染的诊断预测价值。方法回顾分析2016年6月至2017年12月北京协和医院重症医学科收治的77例超高龄重症感染患者(≥85岁),男性患者67例,女性患者10例,年龄85-105岁,平均年龄(92±5)岁,以血培养结果进行分组,其中血培养阳性组50例,血培养阴性组27例,分析WBC、PCT、hs-CRP对血流感染的预测价值。两组间正态分布参数比较应用独立样本t检验。结果血培养阳性组与阴性组WBC无显著差异[12.4(7.8,36.6)×10^9/L比10.7(8.5,18.7)×10^9/L,U=0.109,P=0.124],血培养阳性组PCT[2.6(0.8,7.4)μg/L比1.5(0.6,5.3)μg/L,U=3.015,P=0.004]和hs-CR[119(62,220)mg/L比54(24,80)mg/L,U=7.791,P<0.001]显著高于血培养阴性组。WBC、PCT和hs-CRP预测血培养阳性的受试者工作特征(ROC)曲线下面积分别为0.704(95%CI:0.586-0.822,P<0.01)、0.896(95%CI:0.829-0.964,P<0.001)和0.864(95%CI:0.778-0.949,P<0.001)。其中PCT预测血培养阳性临界值为0.44μg/L,敏感度为70.0%,特异度为92.6%;hs-CRP预测的临界值为50mg/L,敏感度为62.0%,特异度为88.9%。结论PCT和hs-CRP能较WBC更好地早期预测超高龄重症患者的血流感染,PCT和hs-CRP的诊断阈值值得重视。

Objective To investigate the ability of white blood cell (WBC), procalcitonin (PCT) and high-sensitivity C-reactive protein (hs-CRP) in the super-elderly patients with bloodstream infection. Methods It was a retrospective study. A total of 77 patients (≥85 years) admitted to the ICU of Peking Union Medical College Hospital from June, 2016 to December, 2017 were enrolled. The patients included 67 males and 10 females, with an age of 85-105 years and the average age was (92±5) years. According to the results of blood culture, patients were divided into positive blood culture group (n=50) and negative blood culture group (n=27). The data which obeyed normal distribution were compared with single sample t test between the two groups. Results There was no significant difference in WBC level between the positive blood culture group and the negative blood culture group[12.4(7.8, 36.6)×10^9/L vs 10.7(8.5, 18.7)×10^9/L, U=0.109, P=0.124]. Compared to the positive blood culture group, the PCT level [2.6(0.8, 7.4)μg/L vs 1.5(0.6, 5.3)μg/L, U=3.015, P=0.004] and hs-CRP level [119(62, 220) mg/vs 54 (24, 80) mg/L, U=7.791, P<0.001] were significantly higher in the negative blood culture group. The ROC analysis showed that the area under the curves (AUC) of WBC, PCT and hs-CRP was 0.704(95%CI: 0.586-0.822, P<0.01), 0.896(95%CI: 0.829-0.964, P<0.01) and 0.864(95%CI: 0.778-0.949, P<0.01), respectively. The best cutoff value of PCT for discrimination of positive blood culture was 0.44 μg/L, which resulted in a sensitivity of 70.0% and a specificity of 92.6%. The best cutoff value of hs-CRP was 50.35 mg/L, which resulted in a sensitivity of 62.0% and a specificity of 88.9%. Conclusion Compared to WBC, both PCT and hs-CRP have a better ability to predict bloodstream infection in the Super-elderly patients.