降钙素原和白介素6对危重患者导管相关性血行感染的早期诊断及预后价值

Early diagnostic and prognostic value of procalcitonin and interleukin 6 for catheter-related bloodstream infections in critically ill patients

目的探讨降钙素原(PCT)、白介素6(IL-6)和PCT动态变化对危重病患者中心静脉导管相关性血行感染(CRBSI)的早期诊断及预后价值。方法对苏州九龙医院收治的36例中心静脉导管置管后怀疑CRBSI的危重病患者进行前瞻性研究。入组当天采集血样分析PCT、IL-6水平,同时留取血培养和导管标本,并于感染后第1、2、3、7天对患者行PCT监测。将患者分为CRBSI组与非CRBSI组,其中CRBSI组再分为感染控制组和感染未控制组,观察PCT动态变化与预后的关系。结果共有15例患者(41.67%)符合CRBIS诊断标准。在怀疑感染当天,CRBIS组的PCT和IL-6水平均明显高于非CRBIS组,差异有统计学意义(P<0.001和P<0.005)。ROC曲线分析显示:PCT和IL-6曲线下面积分别为0.832和0.78,理想的阳性和阴性预测CRBIS水平为4.3μg/L和464.5 ng/L,该临界值的敏感度为80.0%和77.3.%,特异度为95.2%和66.7%,阳性预测值为92.25%和61.12%,阴性预测值为86.95%和77.76%。在感染后第1、2、3、7天,感染控制组的PCT水平呈逐渐下降趋势,但感染未控制组仍保持在较高水平。结论 PCT和IL-6在早期诊断CRBSI中具有较高的特异性和阴性预测值,PCT的动态变化对病情预后有一定的预测价值。

Objective To evaluate the early diagnostic and prognosis value of procalcitonin （PCT）, interleukin 6 （IL-6）, and PCT kinetics for central venous catheter related bloodstream infections （CRBSI） in selected critically ill patients. Methods Thirty-six patients received central venous catheter, who were suspected of having CRBSI. All the patient blood samples were obtained for detection of PCT, IL-6 levels, and for blood culture on the first day, and catheter were also obtained for euhure. PCT levels were measured on day 1, 2, 3, and 7 after infection. The patients were divided into CRBSI group and non-CRBSI group. The CRBSI group was divided into controlled infeetion group and non-eontrolled infection group, and PCT kinetics for prognostic value was observed. Results Fifteen patients were diagnosed as CRBIS （41.67%）. Levels of PCT and IL-6 were significantly higher in patients with CRBIS than those without CRBIS on the first infection day （ P 〈 0. 001 and P 〈 0. 005）. The ROC curves indicated that the area under the curve （AUC） for PCT and IL- 6 was 0. 832 and 0.78, respectively. The cutoff points of PCT and IL-6 were set to be 4.3 tzg/L and 464.5 ng/L for patients with proven CRBSI, respectively. The corresponding sensitivity, specificity, positive predictive value, and negative predictive value were 80.0% and 77.3%, 95.2% and 66.7%, 92.25% and 61.12%, and 86.95% and 77.76%, respectively. PCT serum levels tended to decrease in patients with controlled CRBSI, whereas in non-controlled patients was proven to remain stably in high level. Conclusion PCT and IL-6 might be valuable early diagnostic parameters for CRBIS with high specificity and negative predictive value, and PCT kinetics has certain predictive value for the prognosis of CRBSI.