ICU床旁肺部超声对呼吸机相关性肺炎早期诊断和动态评估的价值探讨

Value of early diagnosis and dynamic assessment of ventilator-associated pneumonia by ICU bedside ultrasound

目的探讨床旁肺部超声对ICU呼吸机相关性肺炎(VAP)早期诊断和动态评估的价值。方法对56例临床疑诊为VAP的患者同时行肺部超声、胸部CT及实验室检查,以临床最终确诊为标准,分析肺部超声对VAP的早诊断价值。应用受试者特征工作(ROC)曲线分析拟诊VAP后第1、3、7、10天肺部超声评分、白细胞计数(WBC)、降钙素原(PCT)、超敏C反应蛋白(hs-CRP)及临床肺部感染评分(CPIS)预测VAP的诊断效能。结果床旁肺部超声诊断VAP的敏感性和特异性为93.0%、76.9%;胸部CT为95.3%、84.6%,肺部超声与CT比较差异均无统计学意义。随访第1、3、7、10天,VAP患者肺部超声评分及WBC、PCT、hs-CRP感染指标、CPIS评分均随治疗时间的延长而下降。ROC曲线分析显示第1、3、7、10天,肺部超声评分诊断VAP的ROC曲线下面积分别为0.918、0.920、0.900、0.900(均P<0.05),且与CPIS具有较好一致性;其中第1天肺部超声评分95%可信区间(0.823~0.998)和第3天CPIS 95%可信区间(0.806~1)最佳。结论肺部超声诊断VAP的准确率高,能实时动态观察病灶变化,是一种无创、重复性好、可靠的检查手段,对于ICU VAP的早期诊断和动态评估具有较好的临床应用价值。

Objective To investigate the value of bedside lung ultrasound(LUS)in the early diagnosis and dynamic assessment of intensive care unit(ICU)ventilator-associated pneumonia(VAP).Methods A total of 56 patients with clinically suspected VAP were underwent LUS and chest CT and laboratory examinations. Clinical final diagnosis was the criterion,the clinical value of LUS in diagnosing VAP was analyzed. Receiver operating characteristic(ROC)curve was used to analyze diagnostic performance of pulmonary ultrasound score,white blood cell count(WBC),procalcitonin(PCT),high-sensitivity Creactive protein(hs-CRP)and clinical pulmonary infection scores(CPIS)at days 1,3,7 and 10 after treatment.Results The sensitivity and specificity of bedside LUS in diagnosing VAP were 93.0% and 76.9%,respectively.The sensitivity and specificity of chest CT in diagnosing VAP were 95.3% and 84.6%,respectively.There was no significant difference between LUS and CT for diagnosing VAP. At the days 1,3,7 and 10 d after treatment,the pulmonary ultrasound score,WBC,PCT,hs-CRP infection index and CPIS score of VAP patients were decreased with the prolongation of treatment time. ROC analysis showed that the area under curve of the LUS scoring at days 1,3,7 and 10 after treatment were 0.918,0.920,0.900 and 0.900,respectively(all P<0.05),which were consistent with those of CPIS. 95%CI of the bedside LUS score at the 1st day(0.823~0.998)and the 95%CI of CPIS at the 3rd day(0.806 ~1)had the greatest value.Conclusion LUS for diagnosing VAP has high accuracy and can dynamically observe lesion changes in real time.It is a non-invasive,reproducible and reliable method with highly clinical value for early diagnosis and dynamic assessment of ICU VAP.