血清降钙素原和内毒素检测在老年下呼吸道感染病原诊断和疗效判断中的价值

Detection of serum procalcitonin and endotoxin in the pathogen diagnosis of elderly patients with lower respiratory tract infection and evaluation of therapeutic efficiency

目的探讨降钙素原(PCT)和内毒素在老年下呼吸道感染病原诊断和疗效判断中的价值。方法采用前瞻性研究方法,选取2012年1月至2013年12月本院老年下呼吸道细菌性感染者共150例为研究对象,其中革兰阴性菌(G-菌)感染100例和革兰阳性菌(G+菌)感染50例,并选取非细菌感染50例作对照组。对入选患者的血清PCT、内毒素和C-反应蛋白(CRP)做动态检测;采用受试者工作特征曲线(ROC)评估PCT和内毒素预测老年下呼吸道感染病原菌类型;并根据动态检测结果判定抗菌药物的疗效。结果 G-菌感染者PCT和内毒素水平显著高于G+菌感染者。三组PCT和内毒素水平进行两两比较,差异均具有统计学意义(χ2=5.267、6.875,P均<0.05);PCT水平以3.03 ng/ml为截值区分G-菌和G+菌感染老年患者的敏感度为91.67%,特异度为75.0%,曲线下面积为0.8924。内毒素水平以0.146 EU/ml为截值区分G-菌和G+菌感染老年患者的敏感度为83.33%,特异度为90.0%,曲线下面积为0.8639;三组CRP水平差异无统计学意义。老年下呼吸道G-菌感染者治疗前后PCT和CRP水平差异具有统计学意义(χ2=8.245、9.876,P均<0.01)。内毒素水平差异无统计学意义(χ2=0.037、P>0.05)。结论 PCT和内毒素在老年下呼吸道感染病原诊断中具有一定价值,二者联合检测可提高鉴别感染类型的特异度,并可根据其动态变化评估抗菌药物的疗效,进一步验证病原菌类型。

Objective To explore the value of procalcitonin （PCT） and endotoxin in pathogenic diagnosis of elderly patients with lower respiratory tract infection and evaluation of therapeutic efifciency. Methods Total of 150 elderly patients with lower respiratory tract infection were enrolled in this prospective study from January 2012 to December 2013, there were 100 cases with Gram negative （G-） bacteria infection and 50 cases with Gram positive （G＋） bacteria infection, and 50 cases with non-bacteria infection were taken as control group. The levels of serum PCT, endotoxin and C-reaction protein （CRP） of the patients were dynamic detected, and the effect of PCT and endotoxin forecasting types of pathogenic bacteria in elderly patients with lower respiratory tract infections were accessed by operating characteristic curve （ROC）. The antibiotic use were determined by the dynamic results the effects. Results The levels of endotoxin and PCT of G-bacteria infection were higher than that of G＋bacteria infection. The levels of PCT and endotoxin had signiifcant difference between the three groups （χ2=5.267, 6.875;P both〈0. 05）. According to ROC, PCT level at 3.03 ng/ml could distinguish G-bacteria infection from G＋bacteria infection with sensitivity of 91.67%, speciifcity of 75%and the area under the curve of 0.8924. Endotoxin at 0.146 EU/ml was used to distinguish G-bacteria infection from G＋bacteria infection with sensitivity of 83.33% and specificity of 79.17%, while area under the curve of 0.8806; the levels of CRP of three group were no significant differences. Levels of serum PCT and CRP significantly decreased in patients after treatment （χ2= 8.245, 9.876;P both〈0.01） and there was no signiifcant difference of endotoxin between the two groups （χ2=0.037,＆amp;nbsp;P〉0.05）. Conclusions The levels of PCT and endotoxin showed a signiifcant correlation with the diagnosis of elderly patients with lower respiratory tract infection. PCT combined with endotoxin could increase speciifcity of the differential in elderly patients with lower respiratory tract infection, and in accordance with the dynamic assessment of antibiotic therapy, further validation of pathogenic bacteria types.