Meningitis is very literally inflammation of the meninges. Something swollen in a closed space is never good, so it’s important to not miss meningitis when it presents.
Classic triad of meningitis
- Fever
- Neck stiffness
- Brudzinski
- Kernig
- Mental status change – in babies this can be an increase in somnolence or irritability (unconsolably crying)
Important organisms:
- Bacterial
- Listeria*
- E. coli*
- GBS (Group B strep)*
- Neisseria meningitidis
- Strep pneumoniae
- Staph aureus
- Gram neg bacilli
- Haemophilus influenza
- Viral (“aseptic”)
- HSV
- Enterovirus
- HIV
- Mumps
* These are the common ones in the neonatal period
Bacterial:
- Positive Gram stain
- CSF white blood cell (WBC) count >1000/uL with a predominance of neutrophils
- Low CSF glucose concentration <40 mg/dL (2.2 mmol/L)
- Empiric treatment: high doses of a 3rd generation cephalosporin (cefotaxime, ceftriaxone) and vancomycin (this covers antibiotic-resistant S. pneumoniae, N. meningitidis, and Hib)