血清降钙素原检测在神经科重症监护病房脓毒症患者诊断中的价值

Diagnostic value of serum procalcitonin level in patients with sepsis in neurological intensive care units

目的 检测神经科重症监护病房患者血清降钙素原浓度,探讨其对神经科重症监护病房脓毒症患者诊断的价值.方法 检测111例神经科重症监护病房住院患者怀疑脓毒症时血清降钙素原浓度,同时分别采集患者血液或脑脊液标本进行细菌培养及鉴定.组间比较采用x2检验、t检验或非参检验.结果 结合临床表现和细菌学证据确诊为脓毒症患者85例,其中有明确细菌学证据的包括脑膜炎患者40例,血流感染39例,细菌学证据阴性而依据临床症状诊断为脓毒症的患者6例;不能最终确诊脓毒症的患者26例.确诊脓毒症患者和未确诊患者血清降钙素原中位水平分别为3.52（0.05～49.80） μg/L和0.46（0.04～7.63） μg/L,两组差异有统计学意义（Z=-5.013,P＜0.01）.革兰阳性细菌感染和革兰阴性细菌感染患者血清降钙素原中位水平分别为3.21（0.12～36.78） μg/L和3.52（0.05～49.80）μg/L,两组差异无统计学意义（Z=-0.250,P=0.803）,而两组均显著高于未确诊脓毒症患者（Z值分别为-3.479和-4.971,均P＜0.01）.血流感染、脑膜炎和无细菌学证据的脓毒症患者血清降钙素原水平分别为3.99（0.24～49.80）、3.77（0.05～41.06）和3.94（0.05～6.28） μg/L,3组间差异无统计学意义（x2=0.647,P=0.723）,但均显著高于未确诊脓毒症患者（Z值分别为-4.566,-4.528和-2.312,均P＜0.01）.血清降钙素原用于诊断脓毒症的受试者工作特征（ROC）曲线下面积为0.826（95％CI为0.736～0.916,P＜0.01）.ROC曲线最佳临界值为1.825 μg/L,敏感度为82.9％,特异度为75.9％,约登指数为0.588,阳性预测值为93.3％,阴性预测值为65.7％,阳性似然比为3.44,阴性似然比为0.23.结论 在细菌培养结果出来前,血清降钙素原水平对神经科重症监护病房脓毒症的早期诊断具有一定的参考价值.

Objective To test the serum procalcitonin （PCT） concentration of patients in neurological intensive care units （NICU）,and to explore the diagnostic value of PCT level in patients with sepsis in NICU.Methods Serum PCT concentration was detected in 111 patients with suspected sepsis in NICU.At the same time,the samples of blood or cerebral spinal fluid （CSF） were collected to perform bacterial cultures and identifications.Chi-square test,t-test,or nonparametric test were used for statistical analysis.Results Eighty-five patients were diagnosed with sepsis by combining clinical manifestations with evidences of bacteriology.Forty patients with meningitis and 39 patients with bloodstream infection were defined by the evidences of bacteriology,and 6 patients were diagnosed on the basis of clinical symptoms of infection.Twenty-six patients were not diagnosed with sepsis finally.Median level of PCT in sepsis group was 3.52 （0.05-49.80） μg/L,and 0.46 （0.04-7.63） μg/L in non-sepsis group.There was statistical significance between the two groups （Z=-5.013,P〈0.01）.Median level of PCT in patients with gram-positive bacterial infection was 3.21 （0.12-36.78） μg/L and 3.52 （0.05-49.80） μg/L in those with gram-negative bacterial infection,which were not significantly different between groups （Z=-0.250,P=0.803）.However,median levels of PCT in the two groups was both significant higher than undiagnosed sepsis patients （0.46 [0.04-7.63] μg/L; Z=-3.479 and Z=-4.971,respectively,both P〈0.01）.The PCT concentrations in patients with bloodstream infection,meningitis and clinically diagnosed sepsis were 3.99 （0.24-49.80）,3.77 （0.05-41.06） and 3.94 （0.05 -6.28） μg/L,respectively,which was not statistically different among the three groups （x2 =0.647,P=0.723）.However,all of them were all significantly higher than undiagnosed patients （0.46 [0.04-7.63] μg/L; Z=-4.566,Z=-4.528 and Z=-2.312,respectively,all P〈0.01）.The area under receiver operating characteristic （ROC） curve of PCT concentration for the diagnosis of sepsis in NICU was0.826 （95% CI：0.736-0.916,P〈0.01）.The optimal cut-off value of ROC curve was 1.825 μg/L,with sensitivity of 82.9%,specificity of 75.9% and Youden index of 0.588.And positive and negative predictive values were 93.3 % and 65.7%,respectively.Positive and negative likelihood ratios were 3.44 and 0.23,respectively.Conclusion The level of serum PCT may preliminarily predict the sepsis before the bacterial culture result,and it might have potential early diagnostic value of sepsis in NICU patients.