What is the recommended treatment for a patient with suspected meningitis, considering potential viral or bacterial causes and possible complications?

Treatment of Suspected Meningitis

For any patient with suspected meningitis, immediately administer ceftriaxone 2g IV every 12 hours (or cefotaxime 2g IV every 6 hours) PLUS vancomycin 15-20 mg/kg IV every 8-12 hours PLUS dexamethasone 10mg IV every 6 hours, with antibiotics and steroids given within 1 hour of presentation. 1, 2

Immediate Actions (Within First Hour)

Antibiotic Administration

• Start empiric antibiotics within 60 minutes of hospital arrival—delay is strongly associated with increased mortality and poor neurological outcomes 2, 3
• Obtain blood cultures before antibiotics, but never delay antibiotic administration beyond 1 hour to obtain cultures or imaging 1, 2
• If lumbar puncture is delayed for any reason, start antibiotics immediately on clinical suspicion 1, 2

Empiric Antibiotic Regimen by Age

Adults <60 years:

• Ceftriaxone 2g IV every 12 hours OR Cefotaxime 2g IV every 6 hours 1, 2
• PLUS Vancomycin 15-20 mg/kg IV every 8-12 hours 1, 2

Adults ≥60 years or immunocompromised:

• Same as above PLUS Amoxicillin 2g IV every 4 hours (for Listeria coverage) 1, 2

Additional considerations:

• Add Rifampicin 600mg PO/IV twice daily if penicillin-resistant pneumococci suspected (recent travel to high-resistance areas) 1

Adjunctive Dexamethasone

• Give dexamethasone 10mg IV every 6 hours immediately before or simultaneously with first antibiotic dose 1, 2
• Can still initiate dexamethasone up to 12 hours after first antibiotic dose 1
• Continue for 4 days if pneumococcal meningitis confirmed or probable 1, 2
• Stop dexamethasone if another cause confirmed 1

Diagnostic Approach

Lumbar Puncture Timing

• Perform LP within 1 hour if no contraindications present 2
• Contraindications requiring CT first: GCS ≤12, focal neurological deficits, papilledema, new-onset seizures, history of CNS mass lesion, immunocompromise, or signs of severe sepsis 1, 2
• If CT indicated, obtain it AFTER starting antibiotics—do not delay treatment 1, 2
• CSF findings remain diagnostically useful even after antibiotics started 2, 3

Critical Care Referral Criteria

Transfer to ICU immediately if: 1, 2

• Rapidly evolving rash (suggests meningococcemia)
• GCS ≤12 or drop of >2 points
• Cardiovascular instability or severe sepsis
• Hypoxia or respiratory compromise
• Uncontrolled or frequent seizures
• Evidence of limb ischemia

Strongly consider intubation if GCS <12 1

Definitive Therapy (Once Pathogen Identified)

Streptococcus pneumoniae

• Continue ceftriaxone 2g IV every 12 hours OR cefotaxime 2g IV every 6 hours 1
• If penicillin-sensitive (MIC ≤0.06 mg/L): can switch to benzylpenicillin 2.4g IV every 4 hours 1
• If penicillin AND cephalosporin resistant: continue ceftriaxone/cefotaxime PLUS vancomycin PLUS rifampicin 600mg twice daily 1
• Duration: 10 days if recovered by day 10; 14 days if not recovered or if resistant organism 1, 2

Neisseria meningitidis

• Continue ceftriaxone 2g IV every 12 hours OR cefotaxime 2g IV every 6 hours 1
• Alternative: benzylpenicillin 2.4g IV every 4 hours 1
• Give single dose ciprofloxacin 500mg PO if NOT treated with ceftriaxone (for eradication) 1, 2
• Duration: 5 days if recovered 1, 2
• Implement respiratory isolation until 24 hours of effective antibiotics given 1, 4

Common Pitfalls to Avoid

• Never delay antibiotics for imaging—if CT needed, start antibiotics first 1, 2
• Never omit Listeria coverage (amoxicillin) in patients ≥60 years or immunocompromised—this is a critical gap in coverage 2, 3
• Never use inadequate cephalosporin dosing—meningitis requires higher doses than other infections for adequate CSF penetration 5, 3
• Never skip blood cultures, but never delay antibiotics to obtain them 1, 2
• Never give dexamethasone alone without antibiotics—they must be given together 1

Special Considerations

Outpatient Therapy (OPAT)

After initial stabilization, consider OPAT if patient: 1, 2

• Is afebrile and clinically improving
• Has received ≥5 days inpatient therapy
• Has reliable IV access
• Can access medical care 24/7

OPAT regimen: Ceftriaxone 2g IV twice daily (can switch to once daily after first 24 hours) 1

Neonates

• Ceftriaxone contraindicated in neonates ≤28 days if receiving calcium-containing IV solutions 5
• If ceftriaxone used in neonates, infuse over 60 minutes (not 30 minutes) to reduce bilirubin encephalopathy risk 5

Viral Meningitis Consideration

• If viral meningitis suspected based on CSF findings (normal glucose, lymphocytic predominance, no organisms on Gram stain), antibiotics can be discontinued 6, 7
• However, if any hypoglycorrhachia present, continue bacterial coverage regardless of cell type 2