脑脊液乳酸对成人脑出血开颅术后细菌性脑膜炎的诊断价值分析

Diagnostic value of cerebrospinal fluid lactic acid in bacterial meningitis after craniotomy for cerebral hemorrhage in adults

目的探讨脑脊液乳酸在成人脑出血开颅术后细菌性脑膜炎发生中的诊断价值。方法回顾性收集福建医科大学附属第一医院神经外科自2013年4月至2018年4月予开颅手术治疗的162例成人脑出血患者的临床资料,依据是否发生术后细菌性脑膜炎将患者分为感染组(n=75)与非感染组(n=87),采用单因素分析比较2组患者间脑脊液乳酸浓度等脑脊液检测指标的差异,采用多因素Logistic回归分析筛选影响术后细菌性脑膜炎发生的独立因素,采用受试者工作特征曲线(ROC)分析脑脊液乳酸等指标对术后细菌性脑膜炎的预测价值;更进一步将17例脑脊液细菌培养阳性患者分为革兰阳性菌组(n=9)与革兰阴性菌组(n=8),同上方法分析脑脊液乳酸等指标对术后革兰阴性菌脑膜炎的预测价值。结果(1)感染组的脑脊液乳酸浓度[(6.3±2.8)mmol/L]较非感染组[(3.3±1.6)mmol/L]明显升高,差异有统计学意义(P<0.05)。多因素Logistic回归分析显示脑脊液乳酸为术后细菌性脑膜炎发生的独立影响因素(OR=1.547,95%CI:1.029~2.326,P=0.036)。ROC曲线分析显示脑脊液乳酸诊断术后细菌性脑膜炎的曲线下面积为0.854(95%CI:0.790~0.904),最佳截断值为4.61 mmol/L,此时灵敏度为69.3%,特异度为92.0%,阳性预测值为88.1%,阴性预测值为77.7%。(2)革兰阴性菌组脑脊液乳酸浓度[(9.9±2.9)mmol/L]较革兰阳性菌组[(5.2±3.1)mmol/L]明显升高,差异有统计学意义(P<0.05)。ROC曲线分析显示,在脑脊液细菌培养阳性患者中,脑脊液乳酸诊断术后革兰阴性菌脑膜炎的曲线下面积为0.861(95%CI:0.610~0.978),最佳截断值为7.20 mmol/L,此时灵敏度为87.5%,特异度为88.9%,阳性预测值为87.5%,阴性预测值为88.9%。结论检测脑脊液乳酸有助于预测脑出血开颅术后细菌性脑膜炎的发生及鉴别革兰阳性菌与革兰阴性菌脑膜炎。

Objective To explore the diagnostic value of cerebrospinal fluid(CSF)lactic acid(LA)level in bacterial meningitis after craniotomy for cerebral hemorrhage in adults.Methods The clinical data of 162 patients with cerebral hemorrhage,admitted to and accepted craniotomy in our hospital from April 2013 to April 2018,were retrospectively collected;patients were divided into infected group(n=75)and non-infected group(n=87)according to whether postoperative bacterial meningitis occurred;univariate analysis was used to compare the differences of CSF-LA concentration and other indicators of CSF between patients of the two groups;multivariate Logistic regression analysis was used to screen the independent factors affecting the occurrence of postoperative bacterial meningitis;receiver operating characteristic(ROC)curve was used to analyze the predictive values of CSF-LA and other indicators in postoperative bacterial meningitis.Furthermore,17 patients with positive bacterial CSF were divided into Gram-positive(G+)bacteria group(n=9)and Gram-negative(G-)bacteria group(n=8);the predictive values of CSF-LA and other indicators for postoperative meningitis of G-bacteria patients were analyzed in the same way.Results(1)The CSF-LA concentration in infected group([6.3±2.8]mmol/L)was significantly increased as compared with that in non-infected group([3.3±1.6]mmol/L,P<0.05);the results of multivariate Logistic regression analysis showed that CSF-LA was an independent influencing factor for postoperative bacterial meningitis(odd ratio=1.547,95%confidence interval:1.029-2.326,P=0.036);ROC curve results revealed that the area under the curve of CSF-LA concentration in the diagnosis of bacterial meningitis after craniotomy was 0.854(95%confidence interval:0.790-0.904),and the optimal cut-off value was 4.61 mmol/L,with sensitivity of 69.3%,specificity of 92.0%,positive predictive value of 88.1%and negative predictive value of 77.7%.(2)The CSF-LA concentration in G-bacteria group([9.9±2.9]mmol/L)was significantly increased as compared with that in G+bacteria group([5.2±3.1]mmol/L,P<0.05);ROC curve results revealed that,in patients with positive bacterial CSF,the area under the curve of CSF-LA concentration in diagnosis of meningitis with G-bacteria after craniotomy was 0.861(95%confidence interval:0.610-0.978),and the optimal cut-off value was 7.20 mmol/L with sensitivity of 87.5%,specificity of 88.9%,positive predictive value of 87.5%,and negative predictive value of 88.9%.Conclusion Detection for concentration of CSF-LA can help predicting bacterial meningitis after craniotomy for cerebral hemorrhage and identify G+and G-bacteria meningitis.