💉 In suspected meningococcal meningitis/septicaemia, antibiotics should be administered immediately — ideally before hospital referral. If already in hospital, give antibiotics before lumbar puncture (LP). Early treatment saves lives.

🚑 Initial Bacterial Meningitis Management Summary
🫁 ABC stabilization, admit for LP. Perform CT first if signs suggest space-occupying lesion (SOL). 🧪 Take blood cultures and, if feasible, CSF cultures. 💊 Empirical therapy: IV Cefotaxime 2g QDS or Ceftriaxone 2g BD. ➕ Add IV Amoxicillin if Listeria suspected (age >50, pregnant, immunocompromised). ➕ Add Vancomycin if resistant pneumococcus or Pseudomonas suspected. ➕ Add IV Aciclovir if HSV encephalitis considered. 💊 Dexamethasone 0.15 mg/kg IV (≈10 mg) every 6h for 4 days — ideally before or with first antibiotic dose.

🚑 Initial Bacterial Meningitis Management Summary

🫁 ABC stabilization, admit for LP. Perform CT first if signs suggest space-occupying lesion (SOL).
🧪 Take blood cultures and, if feasible, CSF cultures.
💊 Empirical therapy: IV Cefotaxime 2g QDS or Ceftriaxone 2g BD.
➕ Add IV Amoxicillin if Listeria suspected (age >50, pregnant, immunocompromised).
➕ Add Vancomycin if resistant pneumococcus or Pseudomonas suspected.
➕ Add IV Aciclovir if HSV encephalitis considered.
💊 Dexamethasone 0.15 mg/kg IV (≈10 mg) every 6h for 4 days — ideally before or with first antibiotic dose.

📖 About

Untreated acute bacterial meningitis has a mortality of 70–100%.
Treat based on clinical suspicion — do not wait for LP/CT results.
Mortality and morbidity rise with treatment delay.
Atypical presentations common in young, elderly, or immunocompromised.

🧬 Aetiology

Bacterial infection in the subarachnoid space → intense inflammation.
Common organisms: Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae.
Mechanism: bacteria colonise the nasopharynx, produce IgA protease → invade bloodstream → cross BBB.

🧠 Pathology

Purulent exudate in subarachnoid space.
Disrupts cerebral autoregulation, causes vasogenic oedema and thrombophlebitis.
May lead to venous/arterial thrombosis, infarction, hydrocephalus, and raised ICP.

🦠 Common Organisms & Treatment

Organism	Clinical Clues	Empirical Antibiotic
Streptococcus pneumoniae	Adults, alcoholics, post-splenectomy, basal skull fracture	Ceftriaxone/Cefotaxime ± Vancomycin
Neisseria meningitidis	Adolescents, rash, complement deficiency	Ceftriaxone or Cefotaxime
Haemophilus influenzae	Now rare (vaccination)	Cefotaxime/Ceftriaxone
Listeria monocytogenes	Neonates, elderly, pregnancy, immunocompromised	Amoxicillin ± Gentamicin
Staphylococcus aureus	Post-neurosurgery	Vancomycin
Cryptococcus	Immunocompromised (HIV/AIDS)	Amphotericin B + Flucytosine → Fluconazole

🧾 Clinical Presentation

Classic triad: Fever, Neck stiffness, Altered mental status (present in ~45%).
Headache, photophobia, seizures, petechial rash (meningococcus).
Elderly/immunocompromised: subtle, may lack meningism.
Late: CN palsies (VI common), papilloedema, reduced consciousness.

⚠️ Complications

Seizures, stroke, hyponatraemia (SIADH), cerebral abscess.
Hydrocephalus, herniation, septic shock, DIC (esp. meningococcal).

🔎 Investigations

Bloods: FBC, U&E, CRP, glucose, cultures.
CT head: if focal neurology, papilloedema, reduced GCS.
CSF analysis (after LP unless contraindicated):
- Bacterial: high neutrophils, ↑protein, ↓glucose ratio (<0.4).
- Viral: lymphocytic, normal glucose, mild ↑protein.
- TB/fungal: lymphocytic, very low glucose, very high protein.

💊 Management

Immediate antibiotics — don’t delay for LP/CT.
Dexamethasone with/just before first antibiotic dose.
Supportive: fluids, oxygen, seizure management.
Discuss with neurosurgery/ID team if complications (abscess, hydrocephalus).

👨‍👩‍👧 Prophylaxis for Close Contacts

Rifampicin: 600 mg PO BD for 2 days.
Alternatives: Ciprofloxacin 500 mg PO single dose OR Ceftriaxone 250 mg IM once.

📚 References

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Acute Bacterial Meningitis (Adults)