What is the initial treatment approach for meningitis?

Initial Treatment Approach for Meningitis

Bacterial meningitis is a neurologic emergency requiring immediate antimicrobial therapy as soon as possible after the diagnosis is suspected or proven to reduce mortality and morbidity. 1

Immediate Management Algorithm

Step 1: Initial Assessment and Stabilization (First Hour)

• Stabilize airway, breathing, and circulation
• Obtain blood cultures immediately (within 1 hour of arrival)
• Assess Glasgow Coma Scale (GCS) score
• Determine presence of sepsis or shock signs

Step 2: Decision Pathway Based on Clinical Presentation

For patients with suspected meningitis WITHOUT shock or severe sepsis:

1. Perform lumbar puncture (LP) within 1 hour if safe to do so
2. Start antimicrobial therapy immediately after LP is performed
3. If LP cannot be performed within 1 hour, start antimicrobial therapy after blood cultures are taken

For patients with suspected meningitis WITH sepsis or rapidly evolving rash:

1. Start antimicrobial therapy immediately after blood cultures are taken
2. Begin fluid resuscitation with initial bolus of 500 ml crystalloid
3. Defer LP until patient is stabilized

Step 3: Empiric Antimicrobial Therapy

Adults:

• Standard regimen: Vancomycin plus either ceftriaxone or cefotaxime 1
• Ceftriaxone dosage: 1-2 grams IV once daily (not to exceed 4 grams daily) 2
• For meningitis: 2 grams IV every 12 hours is recommended 1, 2

Children:

• Standard regimen: Vancomycin (60 mg/kg/day) plus ceftriaxone (100 mg/kg/day) or cefotaxime (300 mg/kg/day) 3
• For meningitis: Initial dose of 100 mg/kg (not exceeding 4 grams), followed by 100 mg/kg/day 2
• Duration: Usually 7-14 days 2

Step 4: Adjunctive Therapy

• Consider dexamethasone administration before or with first antimicrobial dose 1
• Maintain euvolemia (avoid fluid restriction) 1
• Target mean arterial pressure (MAP) ≥65 mmHg (individualize as needed) 1
• For persistent hypotension despite fluid resuscitation, use norepinephrine as first-line vasopressor 1

Critical Care Considerations

• Consider intensive care unit admission for:

  • GCS <12
  • Persistent seizures
  • Evidence of severe sepsis
  • Hypoxia
  • Signs of raised intracranial pressure 1

• Strongly consider intubation for patients with GCS <12 1

Important Caveats

1. Timing is critical: Do not delay antimicrobial therapy while awaiting neuroimaging or if LP is delayed. Bacterial meningitis is a neurologic emergency with high mortality if treatment is delayed 1.

2. Neuroimaging before LP is indicated for:

   • Focal neurological signs
   • Papilledema
   • Continuous/uncontrolled seizures
   • GCS ≤12 1

3. Antimicrobial resistance: Assume antimicrobial resistance is likely when selecting initial therapy, particularly for pneumococcal infections 1.

4. Fluid management: Avoid fluid restriction in an attempt to reduce cerebral edema; instead, maintain euvolemia 1.

5. Monitoring: Close monitoring for clinical deterioration is essential as patients with meningococcal sepsis can maintain blood pressure until late in disease and then deteriorate rapidly 1.

The initial management of bacterial meningitis requires rapid recognition, diagnostic evaluation, and immediate antimicrobial therapy to optimize patient outcomes and reduce the risk of mortality and neurological sequelae 1, 4.