Bacterial Meningitis Score for Children

The Bacterial Meningitis Score in Children is a six-variable clinical tool designed to stratify patients into "low risk" and "not low risk" categories based on historical and laboratory parameters. Absence of all six factors is necessary to be categorized as low-risk, making this a useful tool to justify disposition decisions.

It was derived in 2007 through a multi-center, retrospective cohort study set in Emergency Departments for patients aged 29 days to 19 years old. Of the 1714 patients deemed low-risk by these criteria, only 2 ended up having bacterial meningitis. This produced a negative predictive value of 99.9% in excluding the diagnosis. Similar results were found in the validation study performed in 2012.

Study authors conclude that given this very low miss rate, most patients with a score of zero can be safely discharged home with consideration for a single dose of antibiotics. The tool does not sub-stratify "not low-risk" patients further, and so complementary information and shared decision making is necessary for the disposition of those patients.

Variable & Associated Points

• CSF Gram stain positive [Yes +1; No 0]
• CSF ANC ≥ 1,000 cells / μL [Yes +1; No 0]
• CSF protein ≥ 80 mg/dL (SI units 800mg/L) [Yes +1; No 0]
• Peripheral blood ANC ≥ 10,000 cells / μL [Yes +1; No 0]
• Seizure at (or prior to) initial presentation [Yes +1; No 0]