Key principles of managing meningitis
The key principles of managing meningitis are outlined in Key principles of managing meningitis.
For advice on managing sepsis or septic shock, including resuscitation, see Key principles of managing sepsis or septic shock.
- It can be difficult to clinically differentiate bacterial meningitis from other diagnoses (eg aseptic meningitis, encephalitis, subarachnoid haemorrhage).
- Arrange urgent transfer of patients with suspected bacterial meningitis to hospital. Administer antibiotics before arrival in hospital if there are signs of meningococcaemia, because meningococcal sepsis can be rapidly fatal.
- CSF microscopy and culture is key to diagnosis and directed therapy for bacterial meningitis. Perform a lumbar puncture as soon as possible, unless contraindicated – see Immediate and early hospital management of meningitis.
- CT scan is not needed in most cases but may be required for patients with possible raised ICP or to investigate differential diagnoses. Do not delay antibiotics for imaging.
- Ideally, obtain microbiological samples (eg CSF, blood) before starting empirical antibiotic therapy.
- Early empirical antibiotic therapy is appropriate when clinical suspicion of bacterial meningitis is high, ideally within 1 hour of presentation to hospital. Do not withhold treatment if there is a significant delay in performing investigations.
- When available, give dexamethasone before or within 20 minutes of antibiotic therapy unless the pathogen is known to be Neisseria meningitidis or Streptococcus agalactiae (group B streptococcus).
CSF = cerebrospinal fluid; CT = computed tomography; ICP = intracranial pressure
When choosing antibiotics for suspected meningitis, consider the antimicrobial susceptibility of likely pathogens, as well as CSF penetration. In general, antibiotics need to be given intravenously to achieve adequate CSF concentrations. Intrathecal therapy is not recommended, except in rare cases that require treatment with drugs that do not adequately penetrate the CSF.
Current evidence favours early treatment with dexamethasone to reduce mortality in adults with Streptococcus pneumoniae (pneumococcal) meningitis and prevent hearing loss in children with Haemophilus influenzae type b (Hib) meningitisBrouwer 2015. Evidence suggests there is no benefit for dexamethasone use in N. meningitidis (meningococcal) meningitis and S. agalactiae meningitis. If corticosteroids are not available, do not delay administration of antibiotics. Dexamethasone should ideally be administered before, or within 20 minutes of, starting antibiotic therapy. However, it can be administered up to 4 hours after starting antibiotic therapy (including when antibiotic therapy is started before hospital admission)van de Beek 2016. After 4 hours, corticosteroids should not be started because the inflammatory response to dying organisms has already been triggered and corticosteroids are of no additional benefit.
If there is any uncertainty in treating a patient with meningitis, seek expert advice from an infectious diseases physician, a clinical microbiologist or an experienced paediatrician.
Some patients with uncomplicated bacterial meningitis can complete their course of treatment at home as part of an established ambulatory antimicrobial therapy program.