Zhou Cheng-dun, Lu Ze-yuan, Ren Nan-zheng, Zhang Gui-chang
Futian People's Hospital, Guangdong Medical College, Shenzhen 518033, Guangdong, China.
Zhongguo Wei Zhong Bing Ji Jiu Yi Xue. 2006 Jun;18(6):370-2.
To explore the diagnostic value of procalcitonin (PCT) quantification in ventilator associated pneumonia (VAP).
Sixty-one patients on ventilators were divided into VAP group and non-VAP group depending on whether the patients developed VAP in 7 days or not. The PCT levels were determined with the method of semi-solid phase immunoassay before and 7 days after instillation of mechanical ventilation in these patients. The PCT levels were graded into four categories, i.e. <0.5 microg/L, 0.5-2.0 microg/L, 2.0-10.0 microg/L and > or =10.0 microg/L. At the same time, C reactive protein (CRP) content and white blood cell (WBC) count were also determined.
Before mechanical ventilation, the CRP and WBC count showed no obvious difference in both groups (all P>0.05). The CRP content and WBC count were found to be obviously elevated in VAP group compared with non VAP group (all P=0.000). The diagnostic sensitivity of CRP and WBC count for VAP were 73.5% (25/34 cases) and 82.3% (28/34 cases) respectively, their specificity was 48.1% (13/27 cases) and 55.5% (15/27 cases), respectively, and their positive prediction rates were 64. 1% (25/39 cases) and 70.0% (28/40 cases), respectively, and their negative prediction rates were 59.1% (13/22 cases) and 71.4% (15/21 cases), respectively. If serum PCT> or =0.5 microg/L was regarded as the cutoff value, the PCT positive percentage did not show difference between VAP group and non VAP group before mechanical ventilation (P>0.05). However, after VAP, the PCT positive percentage of VAP group was much higher than that of non VAP group. The sensitivity of serum PCT determination for the diagnosis of VAP was 85.3% (29/34 cases), with specificity rate 74.1% (20/27 cases), positive prediction rate 80.5% (29/36 cases), and negative prediction rate 80.0% (20/25 cases).
The value of serum PCT has high sensitivity rate in the diagnosis of VAP, so that timely surveillance of serum PCT change is helpful for the diagnosis of VAP in the early stage.
探讨降钙素原（PCT）定量检测在呼吸机相关性肺炎（VAP）中的诊断价值。
将61例使用呼吸机的患者根据其在7天内是否发生VAP分为VAP组和非VAP组。采用半固相免疫测定法测定这些患者机械通气前及通气7天后的PCT水平。PCT水平分为四类，即<0.5μg/L、0.5 - 2.0μg/L、2.0 - 10.0μg/L和≥10.0μg/L。同时，测定C反应蛋白（CRP）含量和白细胞（WBC）计数。
机械通气前，两组患者的CRP和WBC计数无明显差异（均P>0.05）。与非VAP组相比，VAP组的CRP含量和WBC计数明显升高（均P = 0.000）。CRP和WBC计数对VAP的诊断敏感性分别为73.5%（25/34例）和82.3%（28/34例），特异性分别为48.1%（13/27例）和55.5%（15/27例），阳性预测率分别为64.1%（25/39例）和70.0%（28/40例），阴性预测率分别为59.1%（13/22例）和71.4%（15/21例）。若将血清PCT≥0.5μg/L作为临界值，机械通气前VAP组和非VAP组的PCT阳性率无差异（P>0.05）。然而，发生VAP后，VAP组的PCT阳性率远高于非VAP组。血清PCT测定对VAP诊断的敏感性为85.3%（29/34例），特异性为74.1%（20/27例），阳性预测率为80.5%（29/36例），阴性预测率为80.0%（20/25例）。
血清PCT在VAP诊断中具有较高的敏感性，及时监测血清PCT变化有助于VAP的早期诊断。
