The value of cerebrospinal fluid lactate levels in diagnosing CSF infections in pediatric neurosurgical patients

PURPOSE: Diagnosis of cerebrospinal fluid (CSF) infections in patients following neurosurgical procedures can be challenging. CSF lactate (LCSF) has been shown to assist in differentiating bacterial from non-bacterial meningitis in non-neurosurgical patients. The use of lactate in diagnosing CSF-related infections following neurosurgical procedures has been described in adults. The goal of this study was to describe the role of LCSF levels in diagnosing CSF-related infections among neurosurgical children. METHODS: We retrospectively collected data for all pediatric patients treated at a large tertiary pediatric neurosurgical department, for whom CSF samples were collected over a 2-year period. Lactate levels were correlated with other CSF parameters, surgical parameters, presence of CSF infection, and source of CSF sample (lumbar, ventricular, or pseudomeningocele). RESULTS: A total of 215 CSF samples from 162 patients were analyzed. We found a correlation between lactate levels and other CSF parameters. Lactate levels displayed an inconsistent correlation with infection depending on sample origin. Irrespective of the CSF source, lactate levels could not sufficiently discriminate between those with or without infection. Lactate levels were correlated with recent surgery, and, in some of the subgroups, to the extent of blood in CSF. CONCLUSIONS: LCSF levels are influenced by many factors, including the source of sample, recent surgery, and the presence of subarachnoid or ventricular blood secondary to surgery. The added value of LCSF for diagnosing CSF infections in children with a history of neurosurgical procedures is unclear and may be influenced by the extent of blood in the CSF.