Reference range for cerebrospinal fluid values in neonates: 5-year retrospective study.

Cerebro spinal fluid (CSF) parameters (white blood cell count, protein, glucose) in the diagnosis of neonatal bacterial meningitis. To report the reference range of CSF parameters (white blood cell count, protein, glucose) in both term and preterm infants. This was a single center retrospective study over a period of 5 years (2015-2020). We included infants aged 0-3 months admitted to the neonatal unit and infants ≤28 days attending pediatric acute care and who underwent Lumbar Puncture. We excluded infants with evidence of CSF bacteremia, viral infection and traumatic lumbar puncture defined as CSF Red Blood Cell >500 cells/µL. Clinical, demographic, and microbiological data were collected from the hospital database. The study was approved by ethics committee. We identified a total of 518 CSF samples, with 232 CSF samples available for final analysis. 54% of excluded samples were traumatic. Median birth gestation and birth weight of the study cohort were 38 (IQR 35-40) weeks and 3030 (IQR 1965-3565) grams respectively. Median RBC, WBC count, protein and glucose were 15 (IQR 3-85)/µL, 3(IQR 0-8.5)/µL, 0.72 (0.53-1.06) g/L and 2.8 (2.4-3.3) mmol/L respectively. There was no difference in CSF WBC cell count between preterm and term infants. Higher CSF protein content was noted in preterm infants and infants in the first 7 days of life. Use of antibiotics prior to LP was associated with higher CSF protein. Presence of any CSF RBC (including <500 cells/µL) influenced the CSF WBC count and protein content. We have provided a reference range of CSF parameters in neonates without meningitis. CSF WBC count between preterm and term infants were similar with higher CSF protein content in preterm infants and for infants in the first seven days of life. Presence of any CSF RBC influenced CSF parameters.