Significance of Serum Inflammatory Markers in Predicting Bacterial Meningitis amongst Neonates with Sepsis

Introduction: Neonatal meningitis in developing countries is 0.8-6.1 per 1000 live births with mortality of 40-85% and has also has high morbidity. Since, the clinical signs and symptoms of meningitis are non-specific and like those seen in sepsis, Cerebrospinal Fluid (CSF) examination via Lumbar Puncture (LP) is essential to establish the diagnosis of meningitis. Performing a LP has its own set of complications. Hence, to predict meningitis amongst neonates with sepsis serum inflammatory markers are used for the diagnosis of sepsis, so that early antibiotic therapy and LP examination can be avoided. Aim: To investigate the role of serum inflammatory markers, to predict bacterial meningitis amongst neonates with sepsis and to determine the cut-off values for these markers to predict bacterial meningitis amongst neonates with sepsis. Materials and Methods: This was a cross-sectional observational study done over a period of 18 months in the paediatric wards in a tertiary care centre. All neonates presenting with clinical suspicion of sepsis were enrolled. The blood samples were collected for serum inflammatory markers and CSF examination was done as indicated (American Academy of Paediatrics, AAP guidelines). CSF examination findings and serum inflammatory markers were then statistically analysed to determine the significance in predicting bacterial meningitis in neonatal sepsis. A total of 234 neonates were selected as per laboratory investigations for enrollment in the study. Categorical variables were presented in number and percentage (%) and continuous variables were presented as mean±SD (Standard Deviation) and median. Diagnostic tests were used to calculate sensitivity, specificity, Positive Predictive Value (PPV) and Negative Predictive Value (NPV). Results: A total 234 neonates with features suggestive of sepsis and in whom C Reactive Protein (CRP) >10 mg/L, Erythrocyte Sedimentation Rate (ESR)>15 mm, White Blood Cell (WBC) <4000 cells/mm³, Absolute Neutrophil Count (ANC) <1800/mm3 and in whom LP was recommended as per the AAP guidelines were included in the study. A 222 (94.87%) neonates were in the age group 1-10 days. A total of 134 (57.3%) study subjects were males. No significant association of ANC, WBC, ESR and CRP was seen with meningitis (p-value>0.05). Receiver Operator Curve (ROC) for all the four parameters were constructed, they showed performance was non-significant. Conclusion: Based on the current single site study results, it is implicated that diagnosis and management of neonatal meningitis should be solely based on LP since serum inflammatory markers are poor discriminators for meningitis. Future studies should evaluate the diagnostic parameters from other inflammatory markers like Immature to Total Neutrophil (IT) ratio and micro ESR, which, if proven to be of diagnostic value, can reduce the time to initiate management and avert the need for LP in neonatal meningitis