Record opening pressure & CSF appearance
Send for cell count with differential, glucose, protein, gram stain and bacterial cultures
For suspected viral meningitis, add PCR for HSV 1/2, VZV and Enterovirus
For aseptic meningitis: add fungal culture, serum, CSF cryptococcal antigen, and syphilis EIA
Tube 1: Chemistry Tube 2: Micro/Virology Tube 3: Haematology Tube 4: Save for other studies
Appearance: Clear WBC: 0-5/mcgL Predominant cell type: n/a Protein: 0.15-0.5 g/L Glucose: 2.5-4.5 mmol
Appearance: Turbid WBC: ↑↑↑ Predominant cell type: Neutrophils Protein: ↑↑ Glucose ↓↓
Appearance: Clear WBC: ↑ Predominant cell type: Lymphocytes Protein: Normal or mild elevation Glucose ↓
CSF profile may not be typical of bacterial infection in case of partially treated meningitis
Add Acyclovir if CSF profile is compatible with viral meningitis
PCR of CSF can be negative initially in the course of HSV infection. Repeat LP if clinical presentation is consistent with HSV meningoencephalitis