The diagnostic and predictive value of cerebrospinal fluid lactate in children with meningitis. Its relation to current diagnostic methods.

One hundred and thirty-three children with suspected meningitis aged from 11 days to 16 years were investigated with routine cerebrospinal fluid (CSF) laboratory methods: microscopy of a Gram-stained smear, bacterial culture, determination of leukocytes, lactate, and the CSF/blood glucose ratio. On the basis of bacterial cultures and clinical course, the children were classified into three groups: bacterial meningitis (n = 18), aseptic meningitis (n = 28), and a control group (n = 87). The main intention was to study the relation between current diagnostic methods and lactate. CSF lactate levels and cell counts, related significantly (p less than 0.01) better to the presence of bacterial meningitis than CSF/blood glucose ratios. Lactate levels exceed 2.4 mmol/l in all children with bacterial meningitis, but in none of the control group. Of 28 children with aseptic meningitis 3 had lactate in the range 2.5-2.7 mmol/l, while the others had values of 2.4 mmol/l or less. We consider CSF lactate to be the best predictor in the clinical decision to institute antibiotic treatment of children with suspected bacterial meningitis.