Bacterial Meningitis Flashcards
What are the common pathogens?
- Neonates: _____, ______, ______
- Adults: ________________
- Immunocompromised (eg pregnant)/elderly: _________
Group B Strep, E. coli or Listeria;
Strep pneumo > N meningitidis > HI
Listeria
What are pathogens that cause acute meningitis?
viral (eg: HSV), bacterial
What are pathogens that cause subacute/ chronic meningitis?
- TB
- Fungal eg Cryptococcus neoformans
- Brucellosis, syphilis, borrelia
What are the symptoms of bacterial meningitis?
- Headache
- Photophobia
- Phonophobia
- Nuchal rigidity / Neck Stiffness
- Fever
- Nausea & Vomiting
- If severe: Seizures, CN Palsies
- +/- Meningococcemia Rash: Non-Blanching Petechial / Purpuric Rash
What are the signs of bacterial meningitis?
Nuchal rigidity / Neck Stiffness
Positive Kernig’s sign : Painful extension of knee when thigh & knee flexed at 90 deg
Positive Brudzinski sign: Involuntary flexion of hip and knee on passive flexion of neck
Does NOT normally present with altered mental state. If AMS: consider meningoencephalitis or intracranial abscess
In meningococcemia, signs of SHOCK often present before the meningism - emergency!
- _______________ fingers, non-blanching purpuric rash
- May be complicated by __________________
Cold clammy;
bilateral adrenal haemorrhage (Waterhouse–Friderichsen syndrome)
What are the contraindications for LP?
- Any possibility of raised ICP (papilloedema, vomiting, headache) - can lead to herniation 🡪 then consider CT Head to assess ICP first
- Suspected spinal epidural abscess / infection over LP site
- Thrombocytopenia or any other bleeding diathesis
- Cardiorespiratory compromise
What are the infections required for bacterial meningitis?
Blood cultures and LP stat
- Opening pressures, cell count + differential, glucose, protein
- CSF Gram stain, Culture
- +/- CSF AFB, TB Culture, PCR
- +/- CSF HSV PCR
- +/- CSF Treponemal & Non Treponemal Workup
- +/- CSF Cryptococcal Ag if Serum is +ve
Stat CBG
Bloods: FBC, RP, serum procalcitonin, DIVC screen, ABG, lactate
What are the indications for CT head prior to LP?
Features of raised ICP (papilledema, vomiting, headache)
Features of parenchymal pathology
- Focal neurological deficit
- New onset seizure
- Low GCS
- Hx of CNS disease
Immunocompromise
What is LP results for bacterial meningitis?
- pressure
- appearance
- protein (g/L)
- glucose (mmol/L)
- gram stain
- glucose- csf: serum ratio
- WCC
- pressure >30 cmH20
- appearance: turbid
- protein (g/L) >1
- glucose (mmol/L) <2.2
- gram stain : 60-90% positive
- glucose- csf: serum ratio <0.4
- WCC >500, 90% PMN
What is LP results for viral meningitis?
- pressure
- appearance
- protein (g/L)
- glucose (mmol/L)
- gram stain
- glucose- csf: serum ratio
- WCC
- pressure normal (5-20cmH20) or mily increased
- appearance: clear
- protein (g/L) <1
- glucose normal
- gram stain : normal
- glucose- csf: serum ratio > 0.6
- WCC <1000 - 10% have 90% PMN, 30% have >50% PMN
What is LP results for fungal meningitis? - appearance - protein (g/L) glucose (mmol/L) - glucose- csf: serum ratio - WCC
- appearance: fibrin web
- protein: 0.1- 0.5
- glucose 1.6- 2.6
- glucose- csf: serum ratio < 0.4
- WCC 100- 500, monocytes
What is the management of bacterial meningitis?
Respiratory isolation for 24 hrs (if suspected meningococcal meningitis)
ABCs with frequent monitoring
IV empiric antibiotic therapy should be started immediately
- Do NOT DELAY for LP – Abx does NOT affect CSF acutely
- Usually: vancomycin 20mg/kg Q12hrly + ceftriaxone 2g Q12hrly
Adjunctive IV Dexamethasone for strep meningitis to ↓ Cerebral Edema
- Stop only if cultures return and shows other organisms
Start on anti-TB drugs – If uncertain whether bacterial OR TB
Start on Acyclovir – If uncertain whether bacterial OR viral (regardless of HSV)
Start on Ampicillin if suspecting Listeria – ampicillin 2g Q4rly
- Immunocompromised elderly
- OR neonates
Start on cefepime /ceftazidime to cover pseudomonas – for pt w/ penetrating head trauma; post neuroSx; immunocompromised
IV penicillin G 4 megaunits stat or IV ceftriaxone 2g Q12hrly for 7 days – if meningococcemia suspected
What is the chemoprophylaxis for close contacts in pt w/ suspected Meningococcal Meningitis?
PO Ciprofloxacin 500mg single dose
IM Ceftriaxone 250mg single dose (There is no PO formulation for ceftriaxone, only IM and IV)
PO Rifampicin 500mg 12hourly for 2 days
