white cell indices and c-reactive protein: predictors of meningitis in neonatal sepsis?

Background objective: to evaluate the utility of specific cut-off values for c- reactive protein (crp) and immature-to-total neutrophil ratio (i/t) as screening tests for meningitis in culture negative early onset sepsis (eos). materials and methods: retrospective chart review of 97 newborns with culture negative sepsis who had lumbar puncture performed as part of the sepsis evaluation in a level iiib nicu at an academic medical center serving a predominantly minority population. meningitis was defined as either a positive cerebrospinal fluid (csf) culture or csf wbc count ≥30/mm. the outcome measures were the sensitivity, specificity and predictive values of crp >40 mg/l and i/t ratio >0.3 for diagnosing meningitis in newborns with eos. results: the sensitivity, specificity and positive predictive value of i/t ratio >0.3, crp >40 mg/l or a combination of these two either at 12 or 24 hours of life were very poor. however, crp >40 mg/l alone or in combination with i/t ratio >0.3 at both 12 and 24 hours of life had negative predictive values of 85-90%. conclusion: crp >40 mg/l and/or i/t ratio >0.3 have poor sensitivity, specificity and predictive values as screening tests for meningitis in culture negative early onset sepsis.