摘要
目的本文旨在探讨PCT结合其他生化指标如CRP(C-反应蛋白)、WBC(白细胞计数)、LPS(内毒素水平)及乳酸水平等的联合检测在诊断ICU细菌性败血症患者的敏感性和特异性,以分析其对于细菌性败血症诊断的指导作用。方法在患者入院初期并使用抗生素前,空腹采集静脉血,同时送检PCT、CRP及血常规。PCT采用免疫化学发光法,CRP采用散射比浊法,血常规用VCS法,内毒素采用动态比浊法,乳酸采用干化学法。阳性标准:血清PCT≥0.05ng/mL;CRP≥10mg/L;WBC≥6×109/L;乳酸≥2.2mmol/L;内毒素≥5 EU/mL。数据使用SPSS18.0软件进行处理,组问均数比较采用方差分析,灵敏性及特异性比较采用χ2检验。P<0.05为差异有统计学意义。结果血培养阳性患者所检测的包括PCT、CRP、WBC及乳酸和内毒素的水平均明显高于血培养阴性患者。且其P值均<0.05,具有统计学意义。血培养阳性组中PCT阳性51例,敏感性为73.19%;血培养阴性组中PCT阴性301例,特异性为83.84%。血培养阳性组中CRP阳性68例,敏感性为98.55%;血培养阴性组中CRP阴性208例,特异性为57.94%。血培养阳性组中WBC阳性57例,敏感性为82.60%;血培养阴性组中WBC阴性293例,特异性为81.62%。血培养阳性组中乳酸阳性30例,敏感性为56.52%;血培养阴性组中乳酸阴性281例,特异性为78.27%。血培养阳性组中内毒素阳性13例,敏感性为18.84%;血培养阴性组中内毒素阴性330例,特异性为91.92%。结论血培养阳性患者和血培养阴性患者间的5个生化指标均有显著地差异,说明这5项生化指标可能与血培养结果之间存在一定的关联。对于各项生化指标的分析可知,没有一种生化指标其敏感性和特异性均能达到95%以上,依然无法替代血培养。临床医师可依据患者的具体病情结合生化指标的水平来预判菌血症,尤其针对于ICU等科室的危重患者,但最终还是需要以血培养结果作为诊断菌血症的标准。
Objective To examine the sensitivity and specificity of procalcitonin（PCT） in combination with other biochemical markers such as C-reactive protein（CRP）,WBC,as well as levels of lipopolysaccharide（LPS） and lactate in the diagnosis of bacterial septicemia in ICU patients and evaluate the clinical utility of such a combination in identifying bacterial septicemia.Methods Venous blood samples were taken from patients at fasting state immediately after they were admitted and before administration of antibiotics for PCT,CRP and routine hematological tests.PCT was determined by immunochemiluminescence assay.CRP was analyzed by nephelometric assay.Routine hematological tests were performed with VCS（volume,conductivity,and scatter） technique.The serum LPS level was evaluated by kinetic turbidimetric assay,and serum lactate level was determined by dry chemical method.Positive result was defined as serum PCT≥0.05ng/mL;CRP≥10 mg/L;WBC≥6×10^9/L;lactate level≥2.2mmol/L;LPS≥5EU/mL.The data were processed and analyzed with SPSS 18.0 software.Analysis of variance（ANOVA） was used to compare the means between groups.The sensitivity and specificity were analyzed by using Chi-square test.P0.05 was defined as statistical significance.Results The levels of PCT,CRP,WBC,lactate and LPS in the patients with positive blood culture were significantly higher than the corresponding parameters in those with negative blood test（P0.05）.In the patients with positive blood culture（n = 69）,the positive result of PCT,CRP,WBC,lactate,and LPS was identified in 51,68,57,30 and 13 patients,respectively.The sensitivity was 73.19%,98.55%,82.60%,56.52%,and 18.84%,respectively.In the patients with negative blood culture（n=359）,PCT,CRP,WBC,lactate,and LPS was negative in 301,208,293,281,and 330 patients,respectively.The specificity was 83.84%,57.94%,81.62%,78.27%,and 91.92%,respectively.Conclusions The 5 biochemical markers showed statistically significant difference between the patients with positive bloodcul tureand those with negative blood culture,suggesting these biochemical markers may be associated with the results of blood culture.Our analysis indicates that none of these biochemical markers has its sensitivity and specificity both above 95%.They still cannot replace blood culture.Clinicians can predict the possibility of bacteremia based on the results of these biochemical tests in the context of specific patient conditions,especially in the critically ill ICU patients.The final diagnosis of bacteremia should be confirmedbybloodculture.
出处
《中国医药指南》
2012年第30期7-9,共3页
Guide of China Medicine
关键词
血培养
血流感染
生化指标
C反应蛋白
内毒素
降钙素
白细胞
乳酸
Blood culture
Bloodstream infection
Biochemical marker
C-reactive protein
Lipopolysaccharide
Procalcitonin
White blood cell
Lactate
