What is the appropriate management and treatment for a patient suspected of having meningitis, considering their immune status and past medical history?

Management of Suspected Meningitis

For any patient with suspected meningitis, immediately stabilize airway/breathing/circulation, obtain blood cultures within 1 hour, start empiric antibiotics within 1 hour (after lumbar puncture if no contraindications exist, or immediately if LP is delayed), and administer dexamethasone 10 mg IV simultaneously with or just before the first antibiotic dose. 1, 2, 3

Immediate Assessment (First Hour)

Critical Time-Sensitive Actions

• Document Glasgow Coma Scale score immediately upon arrival to assess severity and identify patients requiring urgent intervention 1, 2
• Obtain blood cultures within 1 hour of hospital arrival, before antibiotic administration 2, 3
• Assess for lumbar puncture contraindications including: 1, 2
  • Focal neurological signs (including abnormal pupils)
  • Papilledema
  • GCS ≤12 (or drop of >2 points)
  • Continuous or uncontrolled seizures
  • Immunocompromised state or history of CNS disease
  • Signs of severe sepsis or rapidly evolving rash
  • Respiratory or cardiac compromise

Lumbar Puncture Decision Algorithm

• If NO contraindications present: Perform LP within 1 hour of arrival, then start antibiotics immediately after 2, 3
• If contraindications present: Start antibiotics immediately (within 1 hour), obtain CT head, then perform LP only if imaging shows no mass effect or elevated intracranial pressure 1, 3
• If antibiotics given before LP: Still perform LP within 4 hours of antibiotic initiation when possible, as CSF findings (elevated WBC, decreased glucose, elevated protein) remain diagnostic even after antibiotics 1, 3

Empiric Antibiotic Therapy

Adults <60 Years (Immunocompetent)

Ceftriaxone 2g IV every 12 hours PLUS Vancomycin 15-20 mg/kg IV every 8-12 hours 1, 3, 4

• Alternative if penicillin allergy: Chloramphenicol 25 mg/kg IV every 6 hours 1

Adults ≥60 Years OR Immunocompromised

Ceftriaxone 2g IV every 12 hours PLUS Vancomycin 15-20 mg/kg IV every 8-12 hours PLUS Amoxicillin 2g IV every 4 hours (for Listeria coverage) 1, 3

• Alternative if penicillin allergy: Chloramphenicol 25 mg/kg IV every 6 hours PLUS Co-trimoxazole 10-20 mg/kg (trimethoprim component) in four divided doses 1

Special Considerations for Resistance

• Add Rifampicin 600 mg IV/PO every 12 hours if patient has traveled within 6 months to regions with high pneumococcal resistance rates 1
• Vancomycin is already included in standard empiric therapy to cover resistant pneumococci 1, 3

Adjunctive Dexamethasone Therapy

Dexamethasone 10 mg IV every 6 hours should be started immediately before or simultaneously with the first antibiotic dose 1, 3

• Continue for 4 days if pneumococcal meningitis is confirmed or probable based on CSF parameters 1, 3
• Stop dexamethasone if another cause is confirmed (meningococcal, viral, etc.) 1
• Dexamethasone can still be initiated up to 12 hours after the first antibiotic dose if not given initially 1

Definitive Therapy (Once Pathogen Identified)

Streptococcus pneumoniae (Pneumococcal Meningitis)

• Continue ceftriaxone 2g IV every 12 hours for 10 days if recovered by day 10 1, 3
• Extend to 14 days if not recovered by day 10 or if penicillin/cephalosporin resistant 1
• If penicillin-sensitive (MIC ≤0.06 mg/L): Can switch to benzylpenicillin 2.4g IV every 4 hours 1
• If both penicillin and cephalosporin resistant: Continue ceftriaxone PLUS vancomycin PLUS rifampicin 600 mg every 12 hours 1

Neisseria meningitidis (Meningococcal Meningitis)

• Continue ceftriaxone 2g IV every 12 hours for 5 days if recovered by day 5 1, 3
• Alternative: Benzylpenicillin 2.4g IV every 4 hours 1
• Add single dose ciprofloxacin 500 mg PO for eradication if not treated with ceftriaxone 1, 3

Critical Care Transfer Criteria

Transfer to ICU immediately if patient has: 1, 3

• Rapidly evolving rash
• GCS ≤12 (or drop of >2 points)
• Evidence of limb ischemia or cardiovascular instability
• Hypoxia or respiratory compromise
• Frequent or uncontrolled seizures
• Altered mental state requiring monitoring or organ support

Strongly consider intubation if GCS <12 1, 2

Duration of Therapy and Transition

Inpatient to Outpatient Transition

• Consider outpatient parenteral antibiotic therapy (OPAT) if patient is: 1

  • Afebrile and clinically improving
  • Able to take oral fluids and medications
  • Has reliable IV access and no other acute medical needs
  • Willing to participate with family/carer support

• OPAT regimen: Ceftriaxone 2g IV twice daily for first 24 hours, then can switch to once daily dosing 1

• Add rifampicin 600 mg PO twice daily if treating penicillin-resistant pneumococci at home 1

Critical Pitfalls to Avoid

• Never delay antibiotics beyond 1 hour while waiting for LP or neuroimaging—this directly increases mortality 2, 3, 5, 6
• Do not use calcium-containing diluents (Ringer's solution, Hartmann's solution) with ceftriaxone due to precipitation risk 4
• Do not forget Listeria coverage (amoxicillin) in patients ≥60 years, immunocompromised, diabetic, or on immunosuppressive drugs 1, 3
• Do not give dexamethasone for meningococcal meningitis beyond confirming it's not pneumococcal—stop once another cause is identified 1
• Do not use glycerol or therapeutic hypothermia—these are not recommended and provide no benefit 1

Special Populations

Immunocompromised Patients

• Always add amoxicillin 2g IV every 4 hours to empiric regimen for Listeria coverage 1, 3
• Consider broader differential including fungal and tuberculous meningitis 7, 8
• Seek infectious disease consultation early 1

Patients with Past CNS Disease

• History of CNS mass lesion, stroke, or focal infection requires CT before LP 3
• May need longer duration of therapy (14 days) 1