CNS infections

what is the most common bacteria that causes community-acquired meningitis?

strep pneumoniae

what are the s/sx of adult meningitis?

fever

nuchal rigidity

altered mental status

what are the s/sx of meningitis in neonates?

feeding intolerance

apnea

bulging fontanelle

what kind of pt needs a blood culture AND lumbar puncture STAT?

someone that is NOT:

immunocompromised

history of CNS disease

new onset seizure

papilledema

altered consciousness

focal neurologic deficit

what aspects of a CSF analysis would you see in bacterial meningitis?

opening pressure: increased (> 250)

WBC: 1000-5000

protein: increased (100-500)

glucose: decreased (< 45)

what are the pros of using adjunctive dexamethasone in meningitis?

reduce or prevent hearing loss in peds pts with h. influenzae type B

reduce mortality in adults with s. pneumoniae

if dexamethasone is used for meningitis, what is the dose? when should it be administered?

dose: 0.15 mg/kg IV Q6H for up to 96 hours

administered: 10-20 minutes prior to, or concomitant with first dose of antimicrobial therapy

common pathogens in community-acquired meningitis in pts < 1 month old

group B strep

listeria monocytogenes

empiric IV therapy for community-acquired meningitis in pts < 1 month old

ampicillin + cefotaxime

OR

ampicillin + aminoglycoside

common pathogens in community-acquired meningitis in pts 1 month to < 18 years

s. pneumoniae

empiric IV therapy for community-acquired meningitis in pts 1 month to < 18 years

vanco + 3rd gen cephalosporin (ceftriaxone)

common pathogens in community-acquired meningitis in pts 18-50 years

n. meningitidis

empiric IV therapy for community-acquired meningitis in pts 18-50 years

vanco + 3rd gen cephalosporin (ceftriaxone)

common pathogens in community-acquired meningitis in pts > 50 years

n. meningitidis

listeria monocytogenes

empiric IV therapy for community-acquired meningitis in pts > 50 years

vanco + 3rd gen cephalosporin (ceftriaxone) + ampicillin

what pts commonly have listeria monocytogenes as a cause of their community-acquired meningitis? what medication is used for listeria?

very young (< 1 month)

very old (> 50 yrs)

AMPICILLIN

common pathogens in healthcare-associated meningitis in pts with basilar skull fracture

s. pneumoniae

h. influenzae

group a strep

empiric IV therapy for healthcare-associated meningitis in pts with basilar skull fracture

vanco + 3rd gen cephalosporin (ceftriaxone)

common pathogens in healthcare-associated meningitis in pts with penetrating trauma or post neurosurgery or CSF shunt

s. aureus

CoNS

aerobic GNB

empiric IV therapy for healthcare-associated meningitis in pts with penetrating trauma or post neurosurgery or CSF shunt

vanco + cefepime

or

ceftazidime

or meropenem

antibiotic dosing for meningitis is very _____
a. high

b. low

a.

what kind of management can be done for meningitis?

source control (CSF shunts)

antibiotics: intraventricular (directly into brain); very small doses

when do you repeat a lumbar puncture for meningitis pts?

pts who have NOT responded within 48 hours of appropriate empiric tx

how long do you treat meningitis caused by n. meningitidis and h. influenzae?

7 days

how long do you treat meningitis caused by s. pneumoniae?

10-14 days

how long do you treat meningitis caused by group B strep?

14-21 days

how long do you treat meningitis caused by aerobic gram- bacilli?

21 days

how long do you treat meningitis caused by listeria monocytogenes?

≥ 21 days

vaccines are available for 3 of the major causes of bacterial meningitis, what are they?

s. pneumoniae (PCV15 or PCV20)

n. meningitidis (MenACWY)

h. influenzae type B (HIB)

encephalitis is an inflammatory process of the CNS triggered by _________ causes

noninfectious or infectious (viral)

what is the most common cause of encephalitis?

herpes simplex virus (HSV-1 and HSV-2)

what are the hallmark findings on an MRI for encephalitis?

significant edema and hemorrhage within the temporal lobes

what aspects of CSF analysis do you expect in viral encephalitis?

slightly increased WBC: 5-500

rarely increased opening pressure

normal/slightly incr. protein

normal glucose

_______ should be initiated in ALL PTS with suspected encephalitis

acyclovir

T/F there is benefit shown with adjunctive corticosteroid therapy for both encephalitis and meningitis

FALSE

no benefit shown in encephalitis

what is the duration of treatment for HSV encephalitis?

14-21 days