The diagnostic value of cerebrospinal fluid lactate for post-neurosurgical bacterial meningitis: a meta-analysis

Abstract

Background: Bacterial meningitis is not rare in post-neurosurgical patients. If patients are not treated promptly, the mortality rate can reach 20 to 50 %. The concentration of cerebrospinal fluid (CSF) lactate has been reported to be helpful in the diagnosis of bacterial meningitis; however, no systematic evaluations have investigated CSF from a postoperative perspective. In this study, we performed a systematic evaluation and meta-analysis of the efficacy of using CSF lactate concentrations in the diagnosis of post-neurosurgical bacterial meningitis.

Method: We retrieved studies that investigated the diagnostic value of CSF lactate for the diagnosis of post-neurosurgical bacterial meningitis by searching PubMed, EBSCO, the Cochrane Library and ClinicalTrials.gov. All these databases were searched from inception to November 2015. We used Quality Assessment of Diagnostic Accuracy Studies (QUADAS), a tool for the quality assessment of diagnostic accuracy, to evaluate the quality of the included studies. The Meta-DiSc 1.4 and Review Manager 5.3 software programs were used to analyze the included studies. Forest plots and summary receiver operating characteristics (SROC) curves were also drawn.

Results: Five studies, involving a total of 404 post-neurosurgical patients, were selected from 1,672 articles according to the inclusion criteria. The quality of the five included studies was assessed using QUADAS, and the related results are presented in tables. The meta-analysis revealed the following diagnostic values regarding CSF lactate for post-neurosurgical bacterial meningitis: a pooled sensitivity of 0.92 (95 % CI 0.85-0.96), a pooled specificity of 0.88 (95 % CI 0.84-0.92 with significant heterogeneity), a diagnostic odds ratio of 83.09 (95 % CI 36.83-187.46), an area under the curve (AUCSROC) of 0.9601, an SE(AUC) of 0.0122, a Q* of 0.9046 and an SE(Q*) of 0.0179.

Conclusion: The meta-analysis indicated that the CSF lactate concentration has relatively high sensitivity and specificity for the diagnosis of post-neurosurgical bacterial meningitis and thus has relatively good efficacy.

Keywords: Cerebrospinal fluid lactate; Diagnostic value; Meta-analysis; Post-neurosurgical bacterial meningitis.

Fig. 1

Flow diagram of study screening and selection for inclusion. PRISMA flow diagram of our meta-analysis. A total of 523 studies were obtained from PubMed, 190 studies from EBSCO, 130 studies from the Cochrane library, and 829 from ClinicalTrials.gov. After excluding overlapping literature, 1,672 studies were retrieved. We finally included 5 studies in this analysis according to the above inclusion and exclusion criteria

Fig. 2

Forest plot drawn using data from the included studies. Forest plots were drawn according to the results of the meta-analysis using Review Manager 5.2 software. The data extracted from the 5 included studies are shown. TP: true positive; FP: false positive; FN: false negative; TN: true negative

Fig. 3

Begg’s funnel plot. Begg’s funnel plot was drawn using STATA 12. Each circle means that a study included. OR: odd ratio; S.E.: standard error

Fig. 4

Results from the pooled analysis of the included studies. Results of the pooled analysis using a random effects model. The sensitivity, specificity, positive LR, negative LR, and diagnostic OR of all of the included studies were pooled. The pooled sensitivity was 0.92 (95 % CI 0.85–0.96); the pooled specificity was 0.88 (95 % CI 0.84–0.92, with significant heterogeneity); and the diagnostic OR was 83.09 (95 % CI 36.83–187.46). LR: likelihood ratio

Fig. 5

SROC Curve. SROC curves were plotted. Each red point represent an included study. The AUC of the SROC curve was 0.9601, and the Q* was 0.9046. SROC: summary receiver operating characteristic; AUC: area under curve; Q*: the point on the SROC where sensitivity equals specificity