CSF features of bacterial infection present:
high WCC and predominant PMN
Gram negative diplococci
This indicates a potential life threatening Meningococcal meningitis requiring early broad spectrum antibiotics, dexamethasone and resuscitation
Confounders – high red cell count, some mononuclear cells
RBC:WCC = 30:1 – very low and indicates a relatively high WCC
2. What common tests can you request on CSF?
- gram stain
- oligoclonal bands
- extended culture
- cryptoccal antigen and Indian ink stain
- ZN stain for acid fast bacilli
- PCR for enterovirus and HSV
3. What is the normal ratio of red cells to WCC in CSF?
500:1 (may vary depending on peripheral RBC count)
4. What is the role of steroids?
Corticosteroid use in Western countries is supported by evidence from a randomised controlled trial performed in Europe:
The points to note about this trial are:
- dexamethasone 10mg QID for 4 days led to a decrease in death and disability in adults treated for bacterial meningitis
- dexamethasone was administered 10-15 minutes before or at the time of antibiotics (no-one knows if there is benefit in administering steroids in any way other than this and there may be harm)
- the benefit was only demonstrated in patients with pneumococcal meningitis in a setting where resistant pneumococcus was rare (no benefit has been demonstrated in meningococcal meningitis)
Two studies from third world countries have failed to demonstrate a benefit: