Community-acquired Bacterial Meningitis Flashcards

1
Q

What is the pathogenesis of CA-bacterial meningitis?

A
  1. pt is predisposed to factors and colonisation by bacteria that causes meningitis
  2. bacteria gain entry into the body via
    - invasion of mucosal surface
    - para-meningeal focus
    - head trauma
    - anatomical defects in the meninges
    - neurosurgical procedures
  3. in a susceptible host, bacteria enters the CNS
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the risk factors for bacterial meningitis?

A
  • head trauma
  • CNS shunts
  • neurosurgical procedure
  • CSF fistulas or leaks
  • immunosuppression
  • splenectomised pts
  • congenital defects
  • local infections (sinusitis, otitis media, pharyngitis)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the classic triad of symptoms for bacterial meningitis?

A

Headache, neck rigidity, back ache

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the physical signs of bacterial meningitis?

A
  • kernig sign (back pain when raise leg)
  • brudzinski sign (reflex leg kick when head is lifted)
  • bulging fontane (infants)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the symptoms of bacterial meningitis?

A

altered mental status (irritability), photophobia, nausea, vomiting, anorexia
infants: poor feeding habits
n. meningitidis: petechiae or purpura

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the expected of the opening pressure of lumbar puncture in pt with bacterial meningitis?

A

Elevated opening pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Differentiate the glucose levels of CSF in normal, bacterial, and viral meningitis.

A

normal: 2.6-4.5 mmol/L
bact: very low
viral: normal / slightly low

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Differentiate the protein levels of CSF in normal, bacterial, and viral meningitis.

A

normal: < 0.4 g/L
bact: raised, > 1.5 g/L
viral: normal to slightly raised

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Differentiate the WBC levels of CSF in normal, bacterial, and viral meningitis.

A

normal: < 5 cells/mm3
bact: raised, > 100 cells/mm3, mostly neutrophils
viral: raised, 5 - 1000 cells/mm3, mostly lymphocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the pathogens to be considered in empiric treatment of bacterial meningitis in neonates (<1mo)?

A

s. agalactiae, listeria, e. coli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the recommended regimens for empiric treatment of bacterial meningitis in neonates (<1mo)?

A

ceftriaxone + ampicillin (covers listeria)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the pathogens to be considered in empiric treatment of bacterial meningitis in infants (1-23mo)?

A

s. pneumoniae, s. agalactiae, e. coli, n. meningitidis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the recommended regimens for empiric treatment of bacterial meningitis in infants (1-23mo)?

A

ceftriaxone + vancomycin (cover ceftriaxone resistant s. pneumo)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the pathogens to be considered in empiric treatment of bacterial meningitis in children and adults (2-50yrs)?

A

s. pneumoniae, s. agalactiae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the recommended regimens for empiric treatment of bacterial meningitis in children and adults (2-50yrs)?

A

ceftriaxone + vancomycin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the pathogens to be considered in empiric treatment of bacterial meningitis in older adults (>50yrs)?

A

s. pneumo, listeria, aerobic gram neg (e. coli, klebsiella), n. meningitidis

17
Q

What are the recommended regimens for empiric treatment of bacterial meningitis in older adults (>50yrs)?

A

ceftriaxone + vancomycin + ampicillin

18
Q

What is the recommended regimen (inc. duration) for culture-directed treatment of bacterial meningitis caused by s. pneumoniae?

A

penicillin susceptible: pen G or ampicillin
penicillin resistant: ceftriaxone
ceftriaxone resistant / pen allergy: vancomycin + rifampicin
duration: 10-14d

19
Q

What is the recommended regimen (inc. duration) for culture-directed treatment of bacterial meningitis caused by s. agalactiae?

A

penicillin G / ampicillin
mild penicillin allergy: ceftriaxone
duration: 14 - 21d

20
Q

What is the recommended regimen (inc. duration) for culture-directed treatment of bacterial meningitis caused by listeria?

A

penicillin G / ampicillin
pen allergy: bactrim, meropenem
duration: >= 21d

21
Q

What is the recommended regimen (inc. duration) for culture-directed treatment of bacterial meningitis caused by n. meningitidis?

A

penicillin G / ampicillin
pen allergy: ceftriaxone
duration: 5-7d

22
Q

For which age group is adjunctive corticosteroids recommended?

A

all pt > 6w

23
Q

What is the adult dosing regimen of adjunctive corticosteroids?

A

dexamethasone 10mg Q6H, up to 4 days
administer 10-20 min before / at the same time as first abx dose

24
Q

What are the benefits of adjunctive corticosteroids?

A

decreased neurological sequelae and hearing loss in h. influenzae and s. pneumoniae bacterial meningitis
decrease mortality in s. pneumoniae bacterial meningitis

25
What are the risks of adjunctive corticosteroids?
decreased abx penetration S/E: hypertension, hyperglycemia, mental status changes
26
When should adjunctive corticosteroids be discontinued?
when pathogen causing meningitis is not s. pneumoniae / h. influenzae
27
What is the drug of choice for chemoprophylaxis of close contacts of meningococcal meningitis for children and what is its dose for adults, children, and infants (<1mo)?
Rifampicin Adults: 600mg Q12H, 4 doses Children: 10 mg/kg Q12H, 4 doses Infants: 5 mg/kg Q12H, 4 doses
28
What are the other options for chemoprophylaxis of close contacts of meningococcal meningitis?
PO Ciprofloxacin 500mg single dose (adults only) IM ceftriaxone 125 - 250mg single dose