What is the role of steroids, such as dexamethasone, in the treatment of bacterial meningitis?

Role of Steroids in Bacterial Meningitis

Adjunctive dexamethasone therapy is strongly recommended for adults and children with suspected or proven bacterial meningitis, particularly for pneumococcal and H. influenzae meningitis, as it reduces hearing loss, neurological sequelae, and mortality in pneumococcal meningitis. 1

Recommendations for Adults

• Dexamethasone 10 mg intravenously every 6 hours for 4 days is recommended for all adults with suspected bacterial meningitis in high-income countries 1
• The first dose should be administered 10-20 minutes before or at least concomitant with the first antimicrobial dose 1
• If antibiotics have already been started, dexamethasone can still be administered up to 4 hours after the first antibiotic dose 1
• Dexamethasone has shown greatest benefit in pneumococcal meningitis, with significant reduction in unfavorable outcomes (26% vs 52%) and mortality (14% vs 34%) 1
• For suspected pneumococcal meningitis with high resistance patterns, addition of rifampin to vancomycin plus third-generation cephalosporin may be reasonable when using dexamethasone 1

Recommendations for Children

• Dexamethasone 0.15 mg/kg intravenously every 6 hours for 2-4 days is recommended for children with suspected bacterial meningitis 1
• Strongest evidence supports use in H. influenzae type b meningitis, with confirmed reduction in hearing impairment (OR 0.31; 95% CI, 0.14-0.69) 1
• For pneumococcal meningitis in children, evidence suggests benefit for severe hearing loss when dexamethasone is given early (OR 0.09; 95% CI, 0.0-0.71) 1
• Dexamethasone should not be given to children who have already received antimicrobial therapy, as it is unlikely to improve outcomes in this scenario 1

Pathophysiological Rationale

• Dexamethasone attenuates subarachnoid space inflammatory response, which is a major factor contributing to morbidity and mortality in bacterial meningitis 1
• It helps decrease cerebral edema, increased intracranial pressure, altered cerebral blood flow, cerebral vasculitis, and neuronal injury mediated by pro-inflammatory cytokines 1

Special Considerations

• Dexamethasone should be stopped if the patient is discovered not to have bacterial meningitis 1
• It is recommended to discontinue dexamethasone if the causative organism is neither H. influenzae nor S. pneumoniae, although some experts advise continuing regardless of the causative organism 1
• For N. meningitidis meningitis, the benefit is less clear due to lower event rates and smaller numbers in studies 1
• Dexamethasone is not currently recommended for neonatal bacterial meningitis 1
• No beneficial effects have been identified in studies performed in low-income countries 1

Potential Concerns

• When using dexamethasone with vancomycin for resistant pneumococcal meningitis, there are theoretical concerns about reduced CSF penetration of vancomycin 2
• Monitoring for possible adverse effects of dexamethasone is important, though clinical trials have shown it to be generally safe 3
• Secondary fever, gastrointestinal bleeding, and psychiatric manifestations may be more common in patients receiving dexamethasone 4

Algorithm for Dexamethasone Use in Bacterial Meningitis

1. For all patients with suspected bacterial meningitis in high-income countries:

   • Adults: Administer dexamethasone 10 mg IV q6h for 4 days 1
   • Children: Administer dexamethasone 0.15 mg/kg IV q6h for 2-4 days 1

2. Timing of administration:

   • Give first dose 10-20 minutes before or with first antibiotic dose 1
   • If antibiotics already started, can give dexamethasone within 4 hours 1

3. After pathogen identification:

   • Continue if S. pneumoniae or H. influenzae is confirmed 1
   • Consider discontinuing if other pathogens are identified 1
   • Discontinue if bacterial meningitis is ruled out 1

4. Special situations:

   • Do not use in neonates 1
   • In patients with both meningitis and septic shock, benefits are uncertain 5