Diagnostic Value Of CSF-LA In Intracranial Infection After Craniotomy For Cerebral Hemorrhage In Adults

Objective: To explore the diagnostic value of cerebrospinal fluid(CSF)lactic acid(LA)level in intracranial infection after craniotomy for cerebral hemorrhage in adults.Methods: The data of 162 patients after operation for cerebral hemorrhage in our hospital from April 2013 to April 2018 were retrospectively collected.Among them,75 patients were diagnosed with intracranial infection according to the clinical diagnostic criteria,including 17 cases of positive results of CSF bacterial culture.The remaining 87 patients did not meet the clinical diagnostic criteria for intracranial infection during following observation.First,the patients were divided into intracranial infection group(n=75)and non-infected group(n=87)according to the clinical diagnostic criteria of intracranial infection.The CSF-LA concentration,CSF white blood cell count,chloride concentration,glucose concentration,microprotein concentration,percentage of multinucleated cells and CSF red blood cell count were compared between the two groups.After comparison,the indicators with p<0.05 were included in the multivariate analysis,and the indicators meaningful to the multivariate analysis(P <0.05)were used to draw the receiver operating characteristic curves(ROC curve).By calculating area under the curve(AUC)and 95% confidence interval(CI),the research evaluated the value of indicators in predicting the postoperative intracranial infection and determined the diagnostic optimal cut-off value and the corresponding diagnostic sensitivity(SE),specificity(SP),positive predictive value(PPV),negative predictive value(NPV)and Youden Index(Y I).Then,the patients were divided into CSF cultured positive group(n=17)and CSF cultured negative group(n=145),and the above statistical analysis was repeated.In CSF cultured positive group,they were further divided into CSF cultured Gram-positive bacteria(G+ bacteria)group(n=9)and CSF cultured Gram-negative bacteria(G-bacteria)group(n=8),and CSF indexes were compared between the two groups.Results: 1.The CSF-LA concentration,white blood cell count,microprotein concentration,percentage of multinucleated cells and red blood cell count in infection group were significantly increased compared with those in non-infection group,while the CSF chloride and glucose concentration significantly declined compared with those in non-infection group,and there were statistically significant differences(P<0.05).The results of multivariate logistic regression analysis showed that the lactate concentration,white blood cell count,microprotein concentration,percentage of multinucleated cells,chloride concentration and glucose concentration were independent factors related to intracranial infection after craniotomy for cerebral hemorrhage.The ROC results revealed that the AUC of lactate concentration in CSF in the diagnosis of intracranial infection after cerebral hemorrhage was 0.854(95% CI:0.790-0.904),the optimal cut-off value was 4.61 mmol/L,SE was 69.3%,SP was 92.0%,PPV was 88.1% and NPV was 77.7%.2.The white blood cell count,lactic acid concentration and microprotein concentration in CSF cultured positive group were significantly increased than those in cultured negative group.The glucose concentration in CSF cultured positive group was significantly decreased than that in negative group.The difference was statistically significant(P<0.05).Multivariate logistic regression analysis revealed that lactic acid concentration of CSF was an independent factor and odds ratio was 1.410(OR=1.410)(P<0.001).The ROC results revealed that the AUC of CSF culture-positive intracranial infection after craniotomy for cerebral hemorrhage diagnosed by lactic acid concentration in the CSF was 0.752(95% CI: 0.678-0.816),the best cut-off value was 7.2mmol/L,SE was 52.9%,SP was 87.6%,PPV was 33.3% and NPV was 94.1%.3.Only CSF-LA concentration in G-bacteria group was significantly increased compared with that in G+ bacteria group,and the difference was statistically significant(P<0.05).The ROC results revealed that,in patients with positive CSF culture,the AUC of lactate concentration in CSF diagnosing intracranial infection with G-bacteria after cerebral hemorrhage was 0.861(95% CI: 0.610-0.978),and the optimal cut-off value was 7.2 mmol/ L,SE was 87.5%,SP was 88.9%,PPV was 87.5%,and NPV was 88.9%.Conclusion: The CSF lactic acid was significantly elevated in patients with intracranial infection after craniotomy for cerebral hemorrhage.The test for concentration of CSF-LA can help predict intracranial infection after craniotomy for cerebral hemorrhage and identify G+ and G-bacteria infections.