What is the treatment for suspected bacterial meningitis?

Management of Suspected Bacterial Meningitis

In suspected bacterial meningitis, immediate administration of appropriate antibiotics is essential - do not delay treatment while waiting for diagnostic confirmation. 1

Initial Assessment and Management

• Stabilize airway, breathing, and circulation as an immediate priority 1
• Obtain blood cultures STAT before starting antibiotics 1
• Perform lumbar puncture within 1 hour of arrival if safe to do so 1
• If lumbar puncture must be delayed (due to need for CT scan or other reasons), start empiric antibiotics immediately after blood cultures are drawn 1
• Document Glasgow Coma Scale score to monitor neurological status 1

Empiric Antibiotic Therapy

• For adults <60 years: Ceftriaxone 2g IV every 12 hours or Cefotaxime 2g IV every 6 hours 2
• For adults ≥60 years: Add Amoxicillin 2g IV every 4 hours to cover Listeria monocytogenes 2
• Pre-hospital antibiotics (benzylpenicillin, cefotaxime or ceftriaxone) should be given if bacterial meningitis is strongly suspected and there may be a delay in hospital admission 1

Adjunctive Therapy

• Start dexamethasone 10mg IV every 6 hours immediately, either shortly before or simultaneously with antibiotics 1
• Continue dexamethasone for 4 days if pneumococcal meningitis is confirmed or probable 1
• Discontinue dexamethasone if another cause of meningitis is identified 1
• Glycerol and therapeutic hypothermia are not recommended 1

Critical Care Considerations

• Involve intensive care teams early for patients with:
  • Rapidly evolving rash 1
  • Evidence of limb ischemia 1
  • Cardiovascular instability 1
  • GCS ≤12 or a drop of >2 points (consider intubation) 1
  • Uncontrolled seizures 1
  • Respiratory compromise or hypoxia 1

Pathogen-Specific Treatment (After Identification)

• Streptococcus pneumoniae: Benzylpenicillin 2.4g IV every 4 hours or ceftriaxone/cefotaxime if penicillin sensitive; duration 10-14 days 2
• Neisseria meningitidis: Ceftriaxone 2g IV every 12 hours; duration 5 days 2
• Listeria monocytogenes: Amoxicillin 2g IV every 4 hours; duration 21 days 2
• Haemophilus influenzae: Ceftriaxone 2g IV every 12 hours; duration 10 days 2
• Gram-negative bacilli: Continue ceftriaxone/cefotaxime and seek specialist advice; duration 21 days 2

Duration of Treatment

• For confirmed bacterial meningitis with identified pathogen, follow pathogen-specific durations 2
• For patients with no identified pathogen, treatment can be discontinued if recovered by day 10 2
• For suspected meningococcal sepsis without lumbar puncture, treatment can be stopped if recovered by day 5 with typical petechial/purpuric rash 2

Common Pitfalls and Caveats

• Do not delay antibiotics while waiting for imaging or lumbar puncture results - bacterial meningitis is a neurologic emergency 3, 4
• The classic triad of neck stiffness, fever, and altered consciousness is present in <50% of cases - maintain high index of suspicion 5
• Antibiotic administration before lumbar puncture can reduce the likelihood of identifying bacteria from CSF culture, but molecular diagnostics can still detect pathogens up to 9 days after antibiotics 1
• Consider recent travel history and consult local infectious disease expertise if patient has visited areas with high resistance rates 2
• Outpatient IV therapy may be considered for clinically well patients who have responded to initial treatment 2

Remember that bacterial meningitis is associated with high morbidity and mortality rates (up to 20% for all causes and 30% for pneumococcal meningitis), making rapid diagnosis and immediate treatment crucial for improving outcomes 5, 4.