Cerebrospinal fluid lactate: measurement of an adult reference interval

Abstract

Background Differentiating bacterial meningitis from viral meningitis is a diagnostic challenge. Cerebrospinal fluid lactate has been proposed as a valuable test to differentiate disease states; however, its use in adults is limited by a lack of robust reference interval data. Methods Cerebrospinal fluid samples with no cells or organisms detected, no culture growth after 48 h, and no increase in cerebrospinal fluid bilirubin were used to derive reference interval data for cerebrospinal fluid lactate in adults ( n = 120). Results A cerebrospinal fluid lactate reference interval of 1.0 (90% CI 0.9–1.1) – 2.2 mmol/L (90% CI 2.0–2.6) was defined. Conclusions Cerebrospinal fluid lactate results are rapidly available to the clinician. When interpreted against the adult reference interval derived in this study, results can help to triage patients presenting with symptoms of meningitis.