Level 1 of 6Core
Meningitis and encephalitis
The core to-do list — diagnose and manage, at a glance
Diagnose— recognise it
- Think of it early: consider meningitis in anyone with fever and headache, in any sudden severe headache, and in anyone with fever plus altered behaviour or reduced consciousness — the classic triad is only 44% sensitive, and Kernig's and Brudzinski's signs may be as little as 5% sensitive.
- Examine all the skin: a non-blanching petechial or purpuric rash develops in more than 80% of meningococcal disease but is often absent early and usually blanching at first — indistinguishable from a viral exanthem, becoming petechial or purpuric over hours.
- Recognise the septicaemic presentation: influenza-like illness, then limb pain, pallor with mottling, cold hands and feet, tachycardia, tachypnoea, poor perfusion and oliguria. Hypotension is late, particularly in children, who present with compensated shock — tachycardia, prolonged capillary refill and a normal blood pressure.
- Suspect encephalitis and give aciclovir when there is personality or behavioural change (often the earliest feature, usually reported by family), progressive reduction in conscious level, seizures, or focal deficits especially dysphasia — fever is present in 90% of viral encephalitis.
- Infants show no meningism: fever, irritability, a bulging or tense fontanelle, high-pitched cry, refusal to feed, floppiness, cold mottled extremities, capillary refill over three seconds. The elderly, immunosuppressed, alcoholic and pregnant present atypically — confusion, falls, "off legs", sometimes without fever. A subacute course over weeks is tuberculous or cryptococcal until disproved.
- Red flags for dying or coning: falling GCS or GCS 8 or less; relative bradycardia with hypertension; abnormal posturing; unequal or unreactive pupils; rapidly extending purpura; mottling, capillary refill over three seconds, oliguria or rising lactate; new focal deficit or seizure. Do not be reassured by normal inflammatory markers — they may be normal in rapidly progressive disease.
Manage now— do this, in order
- Treat on suspicion: the first antibiotic dose is given as soon as bacterial meningitis is seriously considered — before imaging and before lumbar puncture. Delay is the dominant modifiable determinant of death and disability. Where meningococcal disease is diagnosed clinically by the petechial rash, give immediate IV antibiotics and take blood cultures; lumbar puncture is unnecessary.Doctor / Nurse
- Dexamethasone before, or with, the first antibiotic dose: adult 10 mg IV 15-20 minutes before or simultaneously, then 10 mg IV every 6 hours for 4 days (child over 2 months: 0.6 mg/kg/day IV in four divided doses). It is the only agent whose benefit is lost by being given late.Doctor / Nurse
- Adult 18-50, community-acquired: ceftriaxone 2 g IV 12-hourly (or cefotaxime 2 g IV 6-hourly), plus vancomycin 15-20 mg/kg IV 8-12-hourly where resistant pneumococcus is a concern.Doctor / Nurse
- Over 50, pregnant, immunocompromised, alcoholic, diabetic or with malignancy: add ampicillin 2 g IV 4-hourly — cephalosporins do not cover Listeria. In penicillin allergy use co-trimoxazole for the Listeria component.Doctor / Nurse
- Child beyond the neonatal period: ceftriaxone 75-100 mg/kg/day IV (max 4 g/day) in 1-2 divided doses, or cefotaxime 200 mg/kg/day IV (max 8 g/day) in 4 doses. Neonate under 1 month: cefotaxime plus ampicillin (with or without gentamicin) — avoid ceftriaxone (bilirubin displacement, incompatible with calcium-containing infusions). Never use imipenem or ertapenem for meningitis — seizure risk.Doctor / Nurse
- Any encephalitic feature at any age: add aciclovir 10 mg/kg IV 8-hourly, each dose over at least 1 hour (adult 14-21 days; child 30 mg/kg/day in three doses; neonate 20 mg/kg 8-hourly for 14 days, 21 with CNS involvement). Do not stop antibacterials when aciclovir starts, and do not stop aciclovir on a negative early PCR — it may be falsely negative in the first 48 hours.Doctor / Nurse
- Correct shock first — fluid restriction is inappropriate in a hypoperfused patient: crystalloid 500 mL IV over 10-15 minutes in adults, 20 mL/kg boluses in children, reassessing after each; failure to respond after roughly 40-60 mL/kg means vasopressors. Take blood cultures at the same time — positive in up to 75% of meningococcal disease.Doctor / NurseNot available at your setup — Blood culture.
- Correct hypoglycaemia, common in severe meningococcal septicaemia: 50% dextrose 50-100 mL IV in adults (or equivalent 25% or 10% volumes), 10% dextrose 2 mL/kg IV in children; check and replace calcium, magnesium, potassium and phosphate. Do not tap against the contraindications: raised intracranial pressure, uncorrected shock, coagulopathy or thrombocytopenia, respiratory insufficiency, local infection, ongoing convulsions — and a normal CT does not exclude raised pressure.Doctor / Nurse
- Apply droplet precautions for the first 24 hours of effective antibiotics, notify public health, and arrange contact prophylaxis: adult ciprofloxacin 500 mg orally once, or rifampicin 600 mg twice daily for 2 days; child ciprofloxacin 30 mg/kg once (max 500 mg) or rifampicin 10 mg/kg (max 600 mg) twice daily for 2 days; neonate rifampicin 5 mg/kg twice daily for 2 days; pregnancy a single IM dose of ceftriaxone. Arrange audiometry early for every survivor.
Empirical antibiotics — give before imaging and before LP
| Patient | Regimen |
|---|---|
| Adult 18-50 | Ceftriaxone 2 g IV 12-hourly (± vancomycin 15-20 mg/kg 8-12-hourly) |
| > 50 / pregnant / immunocompromised / alcoholic / diabetic | ADD ampicillin 2 g IV 4-hourly (Listeria) |
| Child (post-neonatal) | Ceftriaxone 75-100 mg/kg/day (max 4 g/day) in 1-2 doses |
| Neonate < 1 month | Cefotaxime + ampicillin (± gentamicin) — NO ceftriaxone |
| Post-neurosurgical / shunt | Vancomycin + cefepime 2 g IV 8-hourly (or meropenem) |
| Encephalitic feature | ADD aciclovir 10 mg/kg IV 8-hourly over ≥ 1 h |
Refer / escalate
Escalate immediately — after the first antibiotic and dexamethasone dose, never before it — for falling GCS or GCS 8 or less, signs of raised intracranial pressure, shock unresponsive to 40-60 mL/kg of fluid, rapidly extending purpura, new focal deficit or seizure, or any encephalitic feature requiring aciclovir and neuroimaging.
Read the full lesson free
Create a free account to unlock every page, the level exams, and progress tracking.
Sign up freeLog in