Meningitis Flashcards
what is meningitis?
inflammation of the meninges lining
what are the meninges?
they are layers of membrane surrounding and padding the brain and spinal cord
3 layers - brain > pia mater > arachnoid mater > dura mater
what are the red flag s/s for meningitis?
fever, nuchal rigidity, altered mental status
what are the type types of meningitis?
bacterial meningitis - medical emergency
aspectic meningitis
common causes of bacterial meningitis
<1 mo
- Group B strep, E.coli, Listeria
1-3 mo
- Group B strep, E.coli
> 3mo
- Strep pneumonaie
- N. meningitides (11-17 yo)
- Haemophilius influenzae
- Listeria (65+)
common causes of aseptic meningitis
most common: enteroviruses (Coxsackie virus)
other
- Mumps, varicella-zoster, HSV, adenovirus
- parasites
- fungi
- systemic diseases: sarcoidosis, lupus, and Behcet
- neoplastic: leukemia/metastasis
- drug induced: NSAIDs, abx - sulfamides + penicillins, IVIg therapy, mabs, vaccines - MMR
prevention strategies for meningitis?
vaccinations!
- vs varicella, MMR, neisseria meningitidis, Haemophilus influenzae type B, pneumococcal vaccine, TDap
RF for meningitis?
- <5Y or >65Y
- undervaccination
- immunosuppressed states - meds, cancer, congenital, transplant, asplenia, AIDS
- crowded living spaces
- endemic areas
- alcoholism
- iatrogenic - neurosurg, procedural
- trauma - head involved
- IV drug use
what are the two mechanisms for pathogen entry for infection of the meninges?
- hematogenous spread - from other areas like the resp tract – goes into the sub-arachnoid space and is able to cross the blood-brain barrier which triggers an inflammatory response
- direct spread – direct entry into the head to the meninges or from communicable spaces like in sinusitis or otitis media
what physical exam s/s would we expect to see in meningitis pts?
- positive Kernig’s sign - knee at 90, when knee extended = pain
- positive Brudzinski sign - passive flex of neck = hip or knee flexion
- may see rash - trunk, membranous membranes and extremities for meningococcal disease
- fundoscopy - may see papilledema
- positive jolt accentuation – worsening headache with head/neck movements from side to side
what s/s would i expect to see in meningitis?
- triad: fever, nuchal rigidity, altered mental status
- photophobia and phonophobia
- confusion
- muscle weakness
- neuro deficients/sezuires
- N/V
neonates: bulging fontenelle, irritability, lethargy, poor feeding , posturing, V/D
how does the dev of a bacterial cause vs viral vs fungal cause of meningitis differ?
bacterial = sudden, more severe, medical emergency
viral = has more viral s/s, more of a benign disease process, has some conjunctivitis and pharyngitis
fungal = slow, more chronic
what ix would you order for a suspected meningitis?
- LP for CSF analysis – white cell count, protein count, glucose, CSF glucose: serum glucose, opening pressure, colour, culture and sensitivity, gram stain for bacteria, or fungus and consider PCR for viral
- bloodwork:
- CBC w/ diff
- Electrolytes
- Glucose
- Renal and liver fxn: creatinine and ALT/ALP/GGT - infectious:
- blood culture
- Syphilis serology
- TB testing
- Serum HIV - imaging: head CT
how do you tx meningitis?
PUBLIC HEALTH REPORTABLE
1. stabilize
2. IV fluids
3. supportive → oxygen, pain management, fever control, electrolytes
4. droplet isolation precautions until etiology determined
5. Steroids (dexamethasone) – ↓ inflammatory response → done before or concurrently with abx
6. Consider consulting infectious disease
7. empiric antibiotics
- neonates: ceftriaxime + ampicillin
- kids and adults: ceftriaxone + vancomycin
- 55+, immunocompromised: add ampicillin for listeria coverage
- dex should be given for those with Strep pneumoniae or Hib because improves outcomes
8. if not bacterial, tx etiology
- drug - stop drug
- viral - self limiting, consider antivirals for HSV or varicella-zoster → IV acyclovir (broad antiviral medication)
- fungal - antifungal
