Meningitis

Objectives

To guide the management of patients presenting to medical facilities with suspected central nervous system infection and meningococcal septicaemia.

Scope

This guideline outlines the initial emergency investigation and management of a person with suspected central nervous system infection.

It also covers the initial emergency investigation and management of a person with suspected meningococcal septicaemia.

Meningococcal disease is a reportable disease in England and Wales. Treating clinicians should also consider reporting requirements and public health measures that can be found in separate guidance on notifiable diseases.

Audience

This guideline is intended for the use of registered healthcare professionals fulfilling a general role in forward medical locations or in an Emergency Department on deployed operations.

Initial Assessment & Management

Recognition - Central Nervous System (CNS) infection should be considered in an unwell patient presenting with the following symptoms and signs: 

• Severe headache. 
• Neck stiffness/meningism. 
• High fever. 
• Altered mental status. 
• Photophobia.  
• Phonophobia. 
• Positive Kernig’s or Brudzinki sign (involuntary flexion of knee and hip on flexion of neck).

Assessment:

• Use a structured MARCH approach
• Check blood sugar and treat hypoglyaemia if present.
• Check and monitor vital signs and fluid balance (using a recognised score e.g. NEWS2).
• Complete a full neurological examination.

Treatment:

Administer empiric antibiotics in accordance with the current DMS antimicrobial policy if the patient has signs of sepsis or is unlikely to get a lumbar puncture within 4 hours.

Begin fluid resuscitation with crystalloids if signs of shock.

IV antivirals should be initiated if there is any suspicion of encephalitis, in accordance with the current DMS antimicrobial policy, but do not delay evacuation.

Dexamethasone 10mg IV QDS for 4 days should be started as adjunctive therapy before or up to 12-hrs after first dose of antibiotics to reduce neurological sequelae in possible pneumococcus meningitis.

Initiate urgent MEDEVAC from forward location to a facility providing deployed hospital care.

Note that casualties with reduced GCS, significant sepsis or behavioural disturbance may require an enhanced care team to support evacuation if available in the deployed setting.

Advanced Assessment & Management

Investigation:

Blood tests should be taken as available, including FBC, U&E, CRP, lactate, coagulation function and blood cultures (ideally prior to antibiotics).

Most deployed hospital laboratory facilities will be able to perform CSF analysis of common pathogens. Perform a lumbar puncture (LP) if these facilities are present. 

Take 4 X 5ml CSF samples for analysis:  

• Measure CSF opening pressure (normal <25mm CSF).
• CSF microscopy/Gram stain, culture, and protein.
• CSF glucose and lactate (with a paired serum glucose taken at that time).
• CSF bacterial and viral PCR.  

Lumbar Puncture can precipitate fatal coning in someone with raised ICP.

A routine CT brain should be conducted for all patients with suspected CNS infection where available.

Arrange urgent CT brain PRIOR to lumbar puncture and review the results before deciding if it is safe to proceed if there are: 

• Risk factors for an evolving space-occupying lesion. 
• Symptoms or signs which might indicate raised intracranial pressure:
  • New focal neurological features (including seizures or posturing).
  • Abnormal pupillary reactions or papilloedema.
  • Relative bradycardia with hypertension
  • GCS score below 10 or a progressive and sustained or a rapid fall in level of consciousness.

If CT imaging is not available or cannot be performed, do not perform a lumbar puncture if any of the above features unless on specialist advice from the infectious diseases reachback service.

Treatment:

Once within deployed hospital care, continue antimicrobial therapy in accordance with the current DMS antimicrobial policy. If prior IM antibiotic dose given, switch to IV regimen without delay - do not wait for the next dose timing.

If Encephalitis cannot be excluded IV Antivirals should also be continued in accordance with the current DMS antimicrobial policy.

If not already commenced, dexamethasone 10mg IV QDS for 4 days should be started as adjunctive therapy before or up to 12-hrs after first dose of antibiotics to reduce neurological sequelae in possible pneumococcus meningitis.

Critical Care support is commonly required and should be sought in line with standard indications.

Prolonged Casualty Care

Continue regular IV antibiotics and antivirals.

Typical antibiotic durations by pathogen are:

• Neisseria meningitidis - 5 days
• H. influenzae - 7–10 days
• S. pneumoniae - 10–14 days
• S. agalactiae - 14–21 days
• Aerobic Gram Negative Bacteria (e.g. E. coli) - 21 days
• Listeria monocytogenes - ≥21 days

Provide supportive care in line with the sepsis management CGO.

Sedation may be required for agitation, see sedation CGO.

Reach back to the infectious diseases reach back service is strongly advised if possible.

Paediatric Considerations

Assess and manage children with a structured MARCH approach.

Pay careful attention to blood glucose monitoring and treat hypoglycaemia aggressively.

Administer empiric antibiotics, using weight based dosing, in accordance with the current DMS antimicrobial policy noting that there may be variations from adult regimes in specific age groups.

Steroids should not be given to children with suspected meningitis in infants <3 months of age.

Otherwise start Dexamethasone 0.15mg/kg IV QDS for 4 days as adjunctive therapy before or up to 12-hrs after first dose of antibiotics to reduce neurological sequelae in possible pneumococcus meningitis.