Meningitis Flashcards
What are contraindications to lumbar puncture in children?
Signs of raised ICP, focal neurological signs, papilloedema, significant bulging of the fontanelle, disseminated intravascular coagulation, signs of cerebral herniation.
What should be obtained instead of a lumbar puncture in patients with meningococcal septicaemia?
Blood cultures and PCR for meningococcus.
What antibiotics are recommended for children under 3 months with meningitis?
IV amoxicillin (or ampicillin) + IV cefotaxime.
What antibiotics are recommended for children over 3 months with meningitis?
IV cefotaxime (or ceftriaxone).
What does NICE advise regarding corticosteroids in children younger than 3 months?
NICE advises against giving corticosteroids.
When should dexamethasone be considered in meningitis management?
If the lumbar puncture reveals frankly purulent CSF, CSF white blood cell count greater than 1000/microlitre, raised CSF white blood cell count with protein concentration greater than 1 g/litre, or bacteria on Gram stain.
What is the management for shock in children with meningitis?
Treat any shock, e.g. with colloid.
What is required for cerebral monitoring in children with meningitis?
Mechanical ventilation if respiratory impairment.
What is the preferred antibiotic for public health notification and prophylaxis of contacts?
Ciprofloxacin is now preferred over rifampicin.
Meningitis causes in 0 - 3 months
Group B Streptococcus (most common cause in neonates), E. coli, Listeria monocytogenes
Meningitis causes in 3 months - 6 years
Neisseria meningitidis, Streptococcus pneumoniae, Haemophilus influenzae
Meningitis causes in 6 years - 60 years
Neisseria meningitidis, Streptococcus pneumoniae
Meningitis causes in > 60 years
Streptococcus pneumoniae, Neisseria meningitidis, Listeria monocytogenes
Meningitis causes in immunosuppressed individuals
Listeria monocytogenes
What are common neurological sequelae of meningitis?
- Sensorineural hearing loss (most common)
- Seizures
- Focal neurological deficit
What are some infective complications of meningitis?
- Sepsis
- Intracerebral abscess
- Pressure
- Brain herniation
- Hydrocephalus
What syndrome are patients with meningococcal meningitis at risk of?
Waterhouse-Friderichsen syndrome (adrenal insufficiency secondary to adrenal haemorrhage).
What is the appearance of CSF in bacterial meningitis?
Cloudy
What is the appearance of CSF in viral meningitis?
Clear/cloudy
What is the appearance of CSF in tuberculous meningitis?
Slight cloudy, fibrin web
What is the appearance of CSF in fungal meningitis?
Cloudy
What is the glucose level in CSF for bacterial meningitis?
Low (< 1/2 plasma)
What is the glucose level in CSF for viral meningitis?
60-80% of plasma glucose*
Mumps is unusual in being associated with a low glucose level in a proportion of cases. A low glucose may also be seen in herpes encephalitis.
What is the glucose level in CSF for tuberculous meningitis?
Low (< 1/2 plasma)
What is the glucose level in CSF for fungal meningitis?
Low
What is the protein level in CSF for bacterial meningitis?
High (> 1 g/l)
What is the protein level in CSF for viral meningitis?
Normal/raised
What is the protein level in CSF for tuberculous meningitis?
High (> 1 g/l)
What is the protein level in CSF for fungal meningitis?
High
What is the white cell count in CSF for bacterial meningitis?
10 - 5,000 polymorphs/mm³
What is the white cell count in CSF for viral meningitis?
15 - 1,000 lymphocytes/mm³
What is the white cell count in CSF for tuberculous meningitis?
30 - 300 lymphocytes/mm³
What is the white cell count in CSF for fungal meningitis?
20 - 200 lymphocytes/mm³
What is the sensitivity of the Ziehl-Neelsen stain for tuberculous meningitis?
20%
What is the sensitivity of PCR for tuberculous meningitis?
75%
Summarise CSF findings in bacterial, viral, tuberculosis and fungal meningitis. (appearance, glucose, protein, white cells)
What is the initial management step for suspected bacterial meningitis?
All patients should be transferred to hospital urgently.
What should be administered in a pre-hospital setting if meningococcal disease is suspected?
Intramuscular benzylpenicillin may be given, as long as this doesn’t delay transit to hospital.
What is the ABC approach in the management of suspected bacterial meningitis?
Airway, Breathing, Circulation, Disability (GCS, focal neurological signs, seizures, papilloedema).
When should a senior review be requested?
If any warning signs are present, such as rapidly progressive rash or poor peripheral perfusion.
What are some warning signs that require senior review?
Examples include: respiratory rate < 8 or > 30 / min, pulse rate < 40 or > 140 / min, GCS < 12.
What is a key decision in the management of suspected bacterial meningitis?
When/whether to attempt a lumbar puncture (LP).
What should be prioritized if there is doubt about performing a lumbar puncture?
IV antibiotics should be given as a priority.
When should lumbar puncture be delayed?
In cases of severe sepsis, severe respiratory/cardiac compromise, or signs of raised intracranial pressure.
What is the management for patients without indication for delayed LP?
IV access, take bloods and blood cultures, lumbar puncture, then IV antibiotics.
What is the recommended IV antibiotic for patients aged 3 months - 50 years?
Cefotaxime (or ceftriaxone).
What adjunctive treatment is recommended for suspected pneumococcal meningitis?
Consider adjunctive treatment with dexamethasone.
What should be done for patients with signs of raised intracranial pressure?
Get critical care input, secure airway, IV access, and arrange neuroimaging.
What investigations should be performed on blood samples?
Full blood count, renal function, glucose, lactate, clotting profile, CRP.
What should be tested in the cerebrospinal fluid (CSF) if an LP is performed?
Glucose, protein, microscopy and culture, lactate, meningococcal and pneumococcal PCR.
What is the BNF recommendation for initial empirical therapy for patients aged > 50 years?
IV cefotaxime (or ceftriaxone) + amoxicillin (or ampicillin).
What prophylaxis should be offered to contacts of patients with meningococcal meningitis?
Prophylactic antibiotics should be given to households and close contacts.
What is the drug of choice for prophylaxis in close contacts of meningococcal meningitis?
Ciprofloxacin is the drug of choice as it is widely available and only requires one dose.
What should be offered to close contacts when serotype results are available?
Meningococcal vaccination, including booster doses for those who had the vaccine in infancy.
Treatment
What is viral meningitis?
Viral meningitis is inflammation of the leptomeninges and cerebrospinal fluid attributed to a viral agent. It is generally considered a more benign condition compared to bacterial meningitis.
How common is viral meningitis?
Approximately 3,000 cases of confirmed viral meningitis are reported yearly, but the actual number is likely higher as many patients do not seek medical services.
What are the common causes of viral meningitis?
Common causes include non-polio enteroviruses (e.g., coxsackie virus, echovirus), mumps, herpes simplex virus (HSV), cytomegalovirus (CMV), herpes zoster viruses, HIV, and measles.
Who is at risk for viral meningitis?
Risk factors include patients at the extremes of age (< 5 years and the elderly), immunocompromised individuals (e.g., those with renal failure or diabetes), and intravenous drug users.
What are the common clinical features of viral meningitis?
Common features include headache, neck stiffness, photophobia (often milder than in bacterial meningitis), confusion, and fevers.
What are less common features of viral meningitis?
Less common features include focal neurological deficits on examination and seizures, which suggest meningoencephalitis.
What investigation is used to confirm viral meningitis?
A lumbar puncture is performed to confirm the diagnosis.
What are the cerebrospinal fluid findings in viral meningitis?
Cerebrospinal fluid findings include:
- Opening Pressure: 10 - 20 cm³ H²O
- Cell count: 10-300 cells/µL
- Cell differential: Lymphocytes
- Glucose: 2.8 - 4.2 mmol/L or 2/3 serum glucose
- Protein: 0.5 - 1 g/dL
What is the management for viral meningitis?
Management includes supportive treatment while awaiting lumbar puncture results. If bacterial meningitis or encephalitis is suspected, broad-spectrum antibiotics (e.g., ceftriaxone and aciclovir) should be administered.
What is the typical course of viral meningitis?
Viral meningitis is generally self-limiting, with symptoms improving over 7 - 14 days, and complications are rare in immunocompetent patients.
When is aciclovir used in viral meningitis?
Aciclovir may be used if the patient is suspected of having meningitis secondary to HSV.
viral vs bacterial meningitis - opening pressure, cell count, cell differential, glucose, protein
