Bacterial Meningitis Management

1. See Also
   1. Bacterial Meningitis
   2. Neisseria Meningitidis
      1. Includes prophylaxis for exposures
2. Management: Antibiotic and adjunctive medication Doses
   1. See Dexamethasone below
   2. Ampicillin
      1. Age under 1 month: 50 mg/kg IV q8-12 hours
      2. Age over 1 month: 50 mg/kg IV q6 hours
      3. Adult: 2g IV q4 hours
   3. Cefotaxime
      1. <1 month old: 50 mg/kg IV q8-12 hours
      2. >1 month old: 200 mg/kg/d IV divide q6-8 hours
      3. Adult: 2g IV q6 hours
   4. Ceftriaxone
      1. <1 month old: 50-75 mg/kg IV divide q12-24 hours
      2. >1 month old: 100 mg/kg/d IV divide q12 hours
      3. Adult: 2g IV q12 hours
   5. Gentamycin
      1. Peds: 2-2.5 mg/kg q8 hours
      2. Adult: 1 mg/kg IV/IM q8h OR 5 mg/kg IV q24 hours
      3. Therapeutic Window
         1. Peak: 5-10 ug/ml
         2. Trough: <2 ug/ml
   6. Vancomycin
      1. Peds: 15 mg/kg q6 hours IV
      2. Adult: 1g IV q6-12 hours
   7. Meropenem
      1. Peds: 40 mg/kg IV q8 hours
      2. Adult: 1g IV q8 hours
3. Management: Empiric Antibiotic Therapy
   1. Low Birth Weight or Preterm Infant
      1. Vancomycin AND
      2. Amikacin OR Ceftazidime
   2. Age < 1 month old
      1. Ampicillin AND
      2. Cefotaxime OR Gentamicin
   3. Age 1-23 months old
      1. Vancomycin AND
      2. Cefotaxime OR Ceftriaxone AND
      3. Dexamethasone (for pneumococcal Meningitis)
      4. Consider adding Rifampin
   4. Age 2 to 50 years old
      1. Vancomycin AND
      2. Cefotaxime OR Ceftriaxone AND
      3. Dexamethasone (for pneumococcal Meningitis)
      4. Consider adding Rifampin
   5. Age >50 years
      1. Vancomycin AND
      2. Ampicillin AND
      3. Ceftriaxone OR Cefotaxime AND
      4. Dexamethasone (for pneumococcal Meningitis)
      5. Consider adding Rifampin
   6. Comorbid CNS conditions
      1. Head Trauma with Basilar Skull Fracture
         1. Vancomycin AND
         2. Ceftriaxone or Cefotaxime
      2. Head Trauma with penetrating trauma
         1. Vancomycin AND
         2. Cefepime or Ceftazidime or Meropenem
      3. Post-Neurosurgery or CSF Shunt
         1. Vancomycin AND
         2. Cefepime or Ceftazidime or Meropenem
      4. CSF Shunt
         1. Vancomycin AND
            1. Used alone in children if Gram Positive infection
            2. Check Gram Stain to confirm no Gram Negative Rods
         2. Cefepime or Ceftazidime or Meropenem
            1. Added in adults and in Gram Negative infection
4. Management: Antibiotics based on CSF Gram Stain Results
   1. Gram Positive Cocci (Pneumococcus)
      1. All cases receive Dexamethasone for 4 days
      2. Antibiotics for 10-14 days
      3. Penicillin MIC <0.1 mcg per ml
         1. Penicillin
      4. Penicllin MIC 0.1 to 1 mcg/ml
         1. Ceftriaxone
      5. Penicillin MIC >2 mcg/ml
         1. Vancomycin and Ceftriaxone
      6. Alternative agents: Meropenem, Aveox of chloramphenicol
   2. Gram Negative Cocci (Meningococcus)
      1. Ceftriaxone for 7 days
   3. Gram Positive Bacilli (Listeria monocytogenes)
      1. Ampicillin AND Gentamycin
   4. Gram Negative Bacilli (H. flu, E. coli, Pseudomonas)
      1. Ceftazidime AND Gentamycin
5. Management: Known Etiology
   1. Infant
      1. Group B Streptococcus (Treat for 14-21 days)
         1. Ampicillin AND
         2. Consider Gentamycin
      2. Coliforms (Treat for 21 days)
         1. Cefotaxime AND
         2. Consider Gentamycin
      3. Pseudomonas
         1. Ceftazidime AND
         2. Consider Gentamycin
      4. Listeria (Treat for 7 days)
         1. Ampicillin AND
         2. Consider Gentamycin
   2. Children and Adults
      1. Pneumococcal Meningitis (Treat for 10-14 days)
         1. Initial Treatment
            1. Ceftriaxone AND
            2. Vancomycin
            3. Dexamethasone
         2. If Minimum Inhibitory Concentration (MIC) <1.0
            1. Continue Ceftriaxone (or Cefotaxime)
            2. May discontinue Vancomycin
         3. If poor clinical response after 24-36 hours THEN
            1. Start Rifampin AND
            2. Discontinue Vancomycin
         4. Course: 10-14 days of antibiotics
      2. HaemophilusInfluenzae (Treat for 7 days)
         1. Beta-lactamase Negative
            1. Ampicillin OR
            2. Cefotaxime OR Ceftriaxone OR
            3. Chloramphenicol OR
            4. Aztreonam
         2. Beta-lactamase Positive
            1. Ceftriaxone OR Cefotaxime OR
            2. Chloramphenicol OR Aztreonam OR
            3. Fluoroquinolone
      3. Neisseria Meningitidis (Treat for 7 days)
         1. Penicillin G OR Ampicillin OR
         2. Ceftriaxone OR Cefotaxime OR
         3. Chloramphenicol OR
         4. Fluoroquinolone
      4. Listeria Monocytogenes
         1. Ampicillin AND
         2. Aminoglycoside (Gentamicin or tobramycin)
6. Management: Reducing Intracranial Pressure
   1. Indications
      1. Meningitis with Pressure >260mm H2O
   2. Methods
      1. Elevate head of bed to 30 degrees
      2. Hyperosmolar agents (mannitol, glycerol)
      3. High Dose Barbiturates
      4. Avoid Hyperventilation
         1. May reduce ICP at expense of cerebral blood flow
7. Management: Dexamethasone
   1. Technique
      1. First dose 15 minutes before antibiotic
   2. Benefits
      1. Reduces subarachnoid space inflammation
      2. Decreases edema, Vasculitis, neuronitis
   3. Risks
      1. May lower Vancomycin efficacy in CNS
      2. Consider using Rifampin with Dexamethasone
         1. Specifically indicated for Pneumococcal Meningitis
   4. Children
      1. Dosing
         1. Dexamethasone 0.4 mg/kg q12h IV for 2 days OR
         2. Dexamethasone 0.15 mg/kg q6h IV for 4 days
      2. Efficacy
         1. Protective against bilateral Hearing Loss
         2. Must be given prior to first dose of antibiotic
   5. Adults
      1. Dosing
         1. Dexamethasone 10 mg IV q6 hours for 4 days
         2. Start 15 minutes before first antibiotic dose
      2. Efficacy
         1. Significantly better outcomes with Dexamethasone
         2. Decreased neurologic sequelae
         3. Improved survival
      3. References
         1. De Gans (2002) N Engl J Med 347:1549-56
8. Prevention: Post-exposure prophylaxis
   1. See Meningococcal Meningitis for specific antibiotic prophylaxis
   2. See GBS Prophylaxis intrapartum if maternal GBS positive
   3. HaemophilusInfluenzae
      1. Indications
         1. Household contact with unvaccinated or under-vaccinated children under age 4 years
      2. Dosing
         1. Rifampin 20 mg/kg/day up to 600 mg/day for up to 4 days
9. Reference
   1. Gilbert (1998) Sanford Guide to Antimicrobial Therapy
   2. Wilson (1991) Harrison's Internal Medicine, p. 651-2
   3. Bamberger (2010) Am Fam Physician 82(12): 1491-8
   4. Choi (2001) Clin Infect Dis 33:1380-5
   5. Tunkel (1997) Am Fam Physician 56(5):1355-62
   6. Tunkel (2004) Clin Infect Dis 39