降钙素原早期诊断呼吸机相关性肺炎的临床价值

Clinical value of procalcitonin on early diagnosis of ventilator-associated pneumonia

目的探讨降钙素原（PCT）诊断呼吸机相关性肺炎（VAP）的临床价值。方法选择本院2012年5月-2014年12月使用呼吸机辅助通气的43例患者,按照在≤7 d的机械通气时间内是否发生VAP,分为VAP组（28例）和非VAP组（15例）,监测体温、肺部体征、痰的改变,并行胸片、支气管深部痰培养检查,抽血检测PCT、白细胞（WBC）计数水平,计算PCT对VAP的早期诊断灵敏度、特异度、阳性预测值和阴性预测值。结果机械通气后VAP组的PCT、WBC、体温较机械通气前升高,且高于非VAP组,两组间差异有统计学意义（P〈0.05）。以PCT≥0.5 ng/ml为阳性预测值,预测VAP的灵敏度为89.29%、特异度86.67%、阳性预测值为92.59%、阴性预测值为81.25%。以ΔPCT在0.25-1.70 ng/ml为阳性预测值,其灵敏度为89.29%、特异度为93.33%、阳性预测值为96.15%、阴性预测值为82.35%。以PCT≥0.5 ng/ml联合ΔPCT在0.25-1.70 ng/ml为阳性预测值,其灵敏度高达100.00%、特异度为93.33%、阳性预测值为96.55%、阴性预测值为100.00%。结论血清定量PCT检测对早期预测诊断VAP具有高灵敏度和特异度。

Objective To explore the value of procalcitonin （PCT） on early diagnosis of ventilator-associated pneumonia （VAP）. Methods 43 patients who used mechanical ventilation as adjuvant therapy in our hospital from May 2012 to December 2014 were selected.According to whether VAP occurred in less than 7 days during mechanical ventilation, they were divided into VAP group （n=28） and non-VAP group （n=15）.Body temperature,pulmonary signs,and changes in sputum was monitored.X-ray check and sputum culture of deep part in bronchus was applied.The level of PCT and white blood cell （WBC） was tested by blood drawing.Early-stage of diagnostic sensitivity,specificity,positive predictive value and negative predictive value of VAP was calculated by PCT. Results After mechanical ventilation,the level of PCT,WBC and body temperature in VAP group increased compared with that before mechanical ventilation （P〈0.05）, and was higher than that of non-VAP group （P〈0.05）.PCT ≥0.5 ng/ml was as threshold value,the diagnostic sensitivity, specificity,positive predictive value and negative predictive value of VAP was 89.29%,86.67%,92.59% and 81.25% re- spectively.APCT at 0.25-1.70 ng/ml was as threshold value,the diagnostic sensitivity,specificity,positive predictive value and negative predictive value of VAP was 89.29%,93.33%,96.15% and 82.35% respectively.PCT≥0.5 ng/ml and APCT at 0.25-1.70 ng/ml was as threshold value,the diagnostic sensitivity,specificity,positive predictive value and negative predictive value of VAP was 100.00%,93.33%,96.55% and 100.00% respectively. Conclusion Serum PCT quantitative detection has a high specificity and sensitivity in early-stage predictive diagnosis on VAP.