Post-Traumatic Meningitis Treatment
Post-traumatic meningitis requires immediate empiric antibiotic therapy with ceftriaxone 2 grams IV every 12 hours, with treatment duration of 10-14 days for most bacterial pathogens, extended to 21 days for Gram-negative organisms like Enterobacteriaceae. 1, 2
Immediate Empiric Antibiotic Therapy
Start antibiotics within 1 hour of clinical suspicion, even before lumbar puncture or imaging if delayed. 1
Standard Empiric Regimen
- Ceftriaxone 2 grams IV every 12 hours is the cornerstone of empiric therapy for post-traumatic meningitis 1, 3
- This dosing achieves adequate CSF concentrations throughout the dosing interval, which is critical for CNS infections 3
- Add vancomycin 15-20 mg/kg IV every 8-12 hours (targeting trough levels of 15-20 μg/mL) if penicillin-resistant Streptococcus pneumoniae is suspected 1, 2
- Vancomycin should never be used alone due to poor CSF penetration, especially if dexamethasone is administered 2
Age-Based Modifications
- For patients ≥60 years old: Add amoxicillin 2 grams IV every 4 hours to cover Listeria monocytogenes 1, 2
- This addition is critical as Listeria is not covered by cephalosporins and requires 21 days of treatment if confirmed 2, 4
Pathogen-Specific Considerations
Post-traumatic meningitis has distinct microbiology compared to community-acquired cases, with higher rates of nosocomial pathogens. 5, 6
Common Pathogens After Trauma
- Gram-positive organisms: Streptococcus pneumoniae remains most common, particularly with basilar skull fractures and CSF leaks 1, 7, 8
- Gram-negative organisms: Pseudomonas aeruginosa, Klebsiella species, Acinetobacter baumannii, and other Enterobacteriaceae are frequent in nosocomial post-traumatic cases 6, 7
- At least 65% of patients are colonized with the causative pathogen before meningitis develops 6
Definitive Therapy Based on Culture Results
Once the pathogen is identified, adjust therapy according to these durations:
- Pneumococcal meningitis: Continue ceftriaxone 2g IV every 12 hours for 10-14 days (longer if slow to respond) 1, 2, 4
- Meningococcal meningitis: 5-7 days of therapy is sufficient 1, 4
- Haemophilus influenzae: 10 days of ceftriaxone 2g IV every 12 hours 1, 2, 4
- Enterobacteriaceae (Gram-negative bacilli): 21 days of therapy is required 1, 2, 4
- Listeria monocytogenes: Switch to amoxicillin 2g IV every 4 hours for 21 days total 1, 2, 4
- Staphylococcus aureus: At least 14 days, though optimal duration is not well-established 4
Adjunctive Dexamethasone Therapy
Administer dexamethasone 10 mg IV every 6 hours starting before or simultaneously with the first antibiotic dose. 1
- Continue for 4 days if pneumococcal meningitis is confirmed or probable 1
- Discontinue if another pathogen is identified 1
- Can still be initiated up to 12 hours after the first antibiotic dose 1
- Dexamethasone reduces mortality and neurological sequelae in pneumococcal meningitis 1
Diagnostic Workup for CSF Leak
All post-traumatic meningitis cases warrant investigation for CSF leak, as this is a critical risk factor for recurrence. 1, 8
Key Clinical Features Suggesting CSF Leak
- Rhinorrhea or otorrhea (clear fluid drainage from nose or ear) 1
- History of basilar skull fracture, particularly anterior cranial fossa 1, 7, 8
- Recurrent meningitis episodes 1, 8
Imaging Studies
- CT cisternography is the diagnostic test of choice to identify CSF leak location 1, 8
- MRI can also be used to identify meningeal disruption 1
- CT imaging may reveal bone fractures at the skull base 8
Treatment Duration Algorithm
Base treatment duration on the identified or presumed pathogen:
- If S. pneumoniae confirmed: 10 days if clinically stable by day 10; extend to 14 days if slow response 1, 2, 4
- If N. meningitidis confirmed: 5-7 days 1, 4
- If H. influenzae confirmed: 10 days 1, 2, 4
- If Gram-negative bacilli (Enterobacteriaceae) confirmed: 21 days 1, 2, 4
- If Listeria confirmed: 21 days 1, 2, 4
- If no pathogen identified but clinically recovered by day 10: Discontinue antibiotics 1, 2
- If no pathogen identified but CSF suggestive of bacterial meningitis: Continue empiric therapy for at least 14 days 4
Critical Care Considerations
Involve intensive care early for patients with specific high-risk features. 1
Indications for ICU Transfer
- Glasgow Coma Scale ≤12 (or drop of >2 points) 1
- Rapidly evolving rash 1
- Cardiovascular instability or evidence of severe sepsis 1
- Uncontrolled seizures 1
- Respiratory compromise or hypoxia 1
- Consider intubation for GCS <12 1
Acute Hydrocephalus
- Post-traumatic meningitis can cause acute hydrocephalus within the first week after injury 9
- This results from CSF flow obstruction or impaired reabsorption 9
- Rapid clinical deterioration over 24 hours may indicate hydrocephalus development 9
- Timely ventricular drainage combined with appropriate antimicrobials can prevent lasting neurological deficits 9
Common Pitfalls to Avoid
- Do not delay antibiotics for imaging or lumbar puncture - start within 1 hour of suspicion 1
- Do not use inadequate treatment duration for Gram-negative organisms - these require 21 days, not the standard 10-14 days 2, 4
- Do not overlook Listeria coverage in patients ≥60 years - add amoxicillin empirically 1, 2
- Do not use vancomycin monotherapy - always combine with ceftriaxone due to poor CSF penetration 2
- Do not miss CSF leak evaluation - this is essential to prevent recurrence and may require neurosurgical repair 1, 8
- Do not shorten therapy based on early clinical improvement alone - complete the full pathogen-specific duration 4
Surgical Management
Neurosurgical consultation is warranted for CSF leak repair after infection resolution. 7, 8
- Reconstructive surgery of the skull base with tissue sealants (e.g., Beriplast P) has shown good outcomes 7
- Six of ten patients in one series required neurosurgical intervention after infection control 7
- Surgical repair prevents recurrent meningitis episodes 8
Prognosis and Sequelae
Post-traumatic meningitis carries significant morbidity and mortality. 9, 5, 6