【摘要】 目的探讨呼吸机呼出气冷凝液(EVC)中降钙素原(PCT)对呼吸机相关性肺炎(VAP)的诊断及预后判断的临床意义。方法 45例进入本研究的呼吸机辅助通气患者按照机械通气5天内是否发生VAP分为VAP组和非VAP组。气管插管第1、3、5天采用电化学发光免疫分析(ELISA)测定EVC中PCT、同时检测外周血C反应蛋白(CRP)浓度及临床肺部感染评分(Clinical Pulmonary Infection Scole,CPIS)。用受试者操作特征曲线(ROC)评价各指标对呼吸机相关肺炎诊断的准确性。结果机械通气第3、5天VAP患者EVC中PCT、CPIS显著高于非VAP患者(P<0.05);ROC曲线分析,EVC中PCT浓度诊断VAP的ROC曲线下面积(AUC)为0.777。以EVC中PCT浓度0.87ng/ml为界值,其诊断VAP的敏感度81%,特异度为64.3%;以PCT≥0.87ng/ml和CPIS≥6分联合诊断VAP,其敏感性无显著改善,为76.7%,但特异性显著提高为88.0%。结论 EVC中PCT浓度对VAP早期诊断有一定的临床价值,以其浓度为0.87ng/ml为界值,有较好的敏感度;将EVC中PCT与CPIS联合诊断VAP,可以显著提高诊断的特异度,从而有效减少诊断假阳性。更多还原

【Abstract】 Objective To investigatethe clinical value of procalcitonin(PCT) in exhaled ventilator condensate(EVC) in the early diagnosis of patients with ventilator associated pneumonia(VAP). Methods Totally forty-five patients requiring assisted breathing with ventilator were divided into VAP group and non-VAP group depending on whether the patients developed VAP or not in 5 days after assisted breathing with ventilator. PCT in EVC was measured on day 1, 3, 5 of intubation by enzyme linked immunosorbent assay(ELISA). At the same time, the peripheral blood C-reactive protein(CRP) concentration, and Clinical Pulmonary Infection Score(CPIS) were measured. The accuracy of these indicators in the diagnosis of ventilator associated pneumonia were evaluated by receiver operating characteristic(ROC) curve.Results PCT and CPIS in EVC of VAP group on day 3 and 5 were significantly higher than those of non-VAP group(P<0.05). ROC analysis indicated the area under the ROC curve(AUC) of PCT in EVC concentration was 0.777. Using 0.87 ng/ml as the best cutoff, the sensitivity was 81% and the specificity was 64.3%. The combined diagnosis of VAP with PCT(≥0.87) ng/ml and CPIS(≥6) showed no significant improvement in sensitivity(76.7%), but significant improvement in specificity(88.0%).Conclusion PCT in EVC had a great diagnostic value in early diagnosis of VAP. Using 0.87 ng/ml as the boundary value, it had the best sensitivity. The combined diagnosis of VAP with PCT and CPIS can significantly improve the diagnostic specificity to reduce false-positive of VAP.更多还原