Editor – We read with interest the recent Clinical Medicine review by Griffiths et al1 on management of acute meningitis, but were disappointed to note that there was no reference to the importance of biochemical analysis of cerebrospinal fluid (CSF) lactate concentration in the diagnosis of acute bacterial meningitis (ABM).
A CSF lactate concentration of >3.8 mmol/L reliably discriminates between viral/aseptic meningitis and ABM,2–4 and a recent UK consensus guideline on management of acute meningitis in adults recommends analysis of CSF lactate in these patients.5 Co-authors of Griffiths’ review paper in Clin Med (McGill and Solomon) were also named contributors to this guideline.
Measurement of CSF lactate is quick and inexpensive, and can be performed on the same CSF sample taken in the fluoride (grey-top) tube, which is also used to measure CSF glucose concentration.
When taken expeditiously from a patient with suspected acute meningitis prior to receipt of antimicrobial therapy, the combination of a negative CSF microscopy / Gram's stain and a CSF lactate concentration result of <3.8 mmol/L can safely allow clinicians to discontinue antibacterial meningitis treatment. This is particularly relevant in patients admitted to smaller district general hospitals, which often do not have access to on-site polymerase chain reaction (PCR) assays or virology laboratory services.
References
- 1.Griffiths M. McGill F. Solomon T. Management of acute meningitis. Clin Med. 2018;18:164–9. doi: 10.7861/clinmedicine.18-2-164. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Sakushima K. Hayashino Y. Kawaguchi T. Jackson JL. Fukuhara S. Diagnostic accuracy of cerebrospinal fluid lactate for differentiating bacterial meningitis from aseptic meningitis: a meta-analysis. J Infect. 2011;62:255–62. doi: 10.1016/j.jinf.2011.02.010. [DOI] [PubMed] [Google Scholar]
- 3.Abro AH. Abdou AS. Ustadi AM, et al. CSF lactate level: a useful diagnostic tool to differentiate acute bacterial and viral meningitis. J Pak Med Assoc. 2009;59:508–11. [PubMed] [Google Scholar]
- 4.Giulieri S. Chapuis-Taillard C. Jaton K, et al. CSF lactate for accurate diagnosis of community-acquired bacterial meningitis. Eur J Clin Microbiol Infect Dis. 2015;34:2049–55. doi: 10.1007/s10096-015-2450-6. [DOI] [PubMed] [Google Scholar]
- 5.McGill F. Heyderman RS. Michael BD, et al. The UK joint specialist societies guideline on the diagnosis and management of acute meningitis and meningococcal sepsis in immunocompetent adults. J infect. 2016;72:405–38. doi: 10.1016/j.jinf.2016.01.007. [DOI] [PubMed] [Google Scholar]