Cerebrospinal fluid glucose level, cerebrospinal fluid/blood glucose ratio in the diagnosis of septic meningitis

Abstract

The value of cerebrospinal fluid (CSF) glucose level and the CSF/blood glucose ratio as discrimination tests between septic and aseptic meningitis was studied in 30 children with septic meningitis and 33 children with aseptic meningitis. The CSF glucose level (27.1 ± 22.5 vs 60.1 ± 14.1 mg%, P < 0.001) and CSF/blood glucose ratio (0.25 ± 0.19 vs 0.61 ± 0.13, p < 0.0001) were significantly lower in the septic group. At CSF glucose level of ≤ 40 mg%, the sensitivity, specificity, positive and negative predictive values for the diagnosis of septic meningitis were 0.733, 1.000, 1.000 and 0.805 respectively. With CSF/blood glucose ratio of ≤ 0.40, the corresponding values were 0.767, 0.970, 0.958 and 0.820 respectively. We conclude that values of CSF glucose ≤ 40 mg% and CSF/blood glucose ratio of ≤ 0.40 are highly specific and predictive of the diagnosis of septic meningitis.