防污染标本刷在医院内感染性肺炎诊断中的应用

THE APPLICATION OF PSB TO DIAGNOSIS OF NOSOCOMINAL PNEUMONIA

目的 :研究防污染标本刷 (PSB)采样法在院内感染性肺炎 (NP)病原学诊断中的作用。方法 :选择气管切开 (或插管 )的患者 10 8例 ,发生NP的为病例组 ( 50例 ) ,未发生NP的为对照组 ( 58例 ) ,所有病例分别用PSB法、吸痰法和常规咽拭子法作细菌定量培养 ,比较各种采样法的敏感性和特异性。结果 :PSB法和吸痰法所分离到的细菌类型基本一致 ,有 5例患者同时分离到 2种致病菌。PSB法和吸痰法的敏感性分别为 92 %与 84 % ;特异性分别为 96.6%与 93.1% ,均显著优于咽拭子法的敏感性及特异性 ( 4 2 % ,2 9.3% ) ,前者 χ2 =19.62 ,P <0 .0 1,后者 χ2 =17.16,P <0 .0 1。PSB法的敏感性和特异性虽然略高于吸痰法 ,但无显著性差异 ,χ2 =1.17,P>0 .0 5。然而吸痰法操作复杂 ,标本处理繁琐 ,污染环节多。结论 :PSB采样法是目前NP病原学诊断上敏感性和特异性均较高的采样技术 ,且操作安全简便 。

Objective:To study the function of protected specimen brush (PSB) used in the microbiological analysis of nosocominal pneumonia (NP). Methods: 108 patients with mechanical ventilation or tracheostom were chosen, 50 of them with NP belonged to case group, and the rest 58 cases without NP belonged to control group. Bacterial culture were made from the specimens obtained by PSB, aspiration, and swab respectively.The sensitivity and specificity of these methods were compared. Results:The species of bacteria separated from PSB were in accordance with those from aspiration. There were 2 species of bacteria separated from 5 patients at the same time. The sensitivity and specificity of PSB, aspiration were 92%, 96.6%, and 84%, 93.1% respectively, significantly higher than those of swab(42% and 29.3%,P<0.01).There were no signifcant differences between PSB and aspiration (P>0.05),however aspiration was more complicated to operate and the specimen was difficult to deal with but easily be contaminated. Conclusion: PSB is an ideal method with higher sensitivity and specificity for microbiological analysis. Moreover,it is safe and easy to operate, and worth spreading in clinical diagnosis.