Exam 4 - CNS Infections Flashcards
what 5 things make up CSF composition/things you look at to figure out infection
Protein Glucose pH WBCs Fluid
CSF is made by ________
choroid plexus
Normal pH in CSF?
7.4
Normal Protein in CSF?
< 50 mg/dL
Normal Glucose in CSF?
50 - 66 % of serum glucose
Normal WBCs in CSF?
< 5 WBC/mL
normal fluid appearance CSF?
clear
3 layers of meninges?
dura mater
arachnoid
pia mater
BBB (blood brain barrier) or BCSFB (blood CSF barrier):
is 5000 x larger than the other
BBB is bigger
where is CSF found?
subarachnoid
BBB (blood brain barrier) or BCSFB (blood CSF barrier):
has ependymal cells to act as active transport system?
BCSFB
What characteristics make an abx penetration into the CSF easier:
Lipid phobic or phillic?
lipidphilic is better
What characteristics make an abx penetration into the CSF easier:
Ionized or unionized?
unionized is better
What characteristics make an abx penetration into the CSF easier:
low or high molecular weight
low is better
What characteristics make an abx penetration into the CSF easier:
high or low protein binding
low protein binding better b/c only free drug can penetrate
meningeal inflammation: help or hurt penetration into CSF?
help!
what drugs have therapeutic concentrations into CSF withOUT meningeal inflammation?
Acyclovir Chloramphenicol Fluconazole Ganciclovr Linezolid metronidazole rifampin FQs
(MR LAG FFC)
what drugs have therapeutic concentrations into CSF with meningeal inflammation?
PCNs 3rd/4th gen cephs aztreonam meropenem colistin vanc
(CV PAM 3rd/4th gen)
what drugs do not get into the CSF no matter if meninges are inflamed?
AGs Amphotericin-B beta lactamase inhibitors Some cephs (1st and 2nd gen) Clindamycin Tetracyclines (SCAT BA)
3 main ways bacteria gains access into the CSF?
hematogenous spread
contiguous spread
direct inoculation
what bugs are common cause of bacterial meningitis: In adults (30 - 50 years old)
S Pneumonaie, N meningitidis
what bugs are common cause of bacterial meningitis: older adults (>50 years old)
S pneumo
N mening
GNR
Listeria
3 most common causes of bacterial meningitis?
H. influenzae
Neisseria meningitidis
s. pneumoniae
3 most common signs of bacterial meningitis
fever
headache
stiff neck
CSF gets obtained via ______
need __#___ tubes for what tests?
LP: lumbar puncture
need 3 tubes: chemistry/hematology/microbiology
Bacterial Findings in CSF for Meningitis:
WBC value?
400 - 5000
Bacterial Findings in CSF for Meningitis:
Differential?
> 80% neutrophils
Bacterial Findings in CSF for Meningitis:
Protein?
elevated:
100 - 500
Bacterial Findings in CSF for Meningitis:
glucose?
< 50%
when should empiric therapy be started?
immediately administered after LP is performed — do not wait to get culture results!
Empiric Treatment options for bacterial meningitis:
Head trauma?
Vanc + 3rd/4th gen cephs (want pseudomonas coverage)
Empiric Treatment options for bacterial meningitis: Older adults (> 50 years old) or Immunosuppressed
Amp + 3rd gen ceph + Vanco
*do 4th gen ceph if immunosuppressed
Empiric Treatment options for bacterial meningitis:
Postneurosugery?
same as head trauma!
Vanc + 3rd/4th gen cephs
Empiric Treatment options for bacterial meningitis:
adults (30 - 50 years old)
3rd gen ceph + vanc
same as kids/adults 4- 29 and infants - kids (1 mo - 4 years
Empiric Treatment options for bacterial meningitis:
children/adults (> 4 - 29 yr)
3rd gen ceph + vanc
Empiric Treatment options for bacterial meningitis:
infants/kids (1 mo - 4 years)
3rd gen ceph + vanc
Empiric Treatment options for bacterial meningitis:
neonates (< 1 month)
ampicillin + cefotaxime
Directed Treatment options for bacterial meningitis:
if S. pneumoniae?
PSSP: PCN G or Ampicillin
PRSP: Vanc + Ceftriaxone
Directed Treatment options for bacterial meningitis:
Group B Strep
Ampicillin (+/- gent)
Directed Treatment options for bacterial meningitis:
S. Aureus
MSSA: Nafcillin!! (Not Cefazolin bc doesnt get into CSF!)
MRSA: Vanc!
Directed Treatment options for bacterial meningitis:
Listeria monocytogenes
Ampicillin (+/- gent)
Directed Treatment options for bacterial meningitis:
Neisseria meningitidis
PCN
or
Ceftriaxone
Directed Treatment options for bacterial meningitis:
H. influenzae
BL (?) + ampicillin
BL + ceftriaxone
Directed Treatment options for bacterial meningitis:
Gram Negative
Ceftriaxone
or
Cefepime
when do you use steroids with bacterial meningitis?
use as adjunctive therapy with H. influenzae or pneumococcal meningitis
possible concern of steroid use in bacterial meningitis?
it will decrease inflammation of meninges — may decrease penetration of antibiotic into the CSF
When to do bacterial meningitis prophylaxis:
For _________ or _______ infections only
H. influenzae or N. meningitidis
When to do bacterial meningitis prophylaxis:
Do for people that are _______ to the patient with the infection
close contacts (household members, sharing sleeping quarters, daycare attendee, NH resident, anyone in crowded confined area with index case)
When to do bacterial meningitis prophylaxis:
Greatest risk for development develops in the _______ following exporsure
week
Bacterial meningitis prophylaxis regimens:
what drug is used?
rifampin
most common cause of fungal meningitis
cryptococcus
Cryptococcal meningitis treatment?
NON-HIV infected:
amphotericin PLUS flucytosine x 2 weeks then fluconazole x 12 weeks
HIV infected:
amphotericin PLUS flucytosine x 2 weeks then fluconazole x 8 weeks then for one year
Diagnosis of Viral Encephalitis:
Clear or cloudy?
clear!!
Diagnosis of Viral Encephalitis:
what type of gram stain?
negative because it aint bacteria
what drug is used for Viral encephalitis herpes simplex/varicella infections?
acyclovir
renally adjust
what drug is used for Viral encephalitis CMV infections?
ganciclovir and foscarnet
what is contiguous spread?
bacteria spread into brain tissue from nearby focus of infections
If HIV infected person: what bugs are we worried about that would cause a brain abscess?
toxoplasma
nocardia
cryptococcus
Brain Abscesses: Empiric Abx of Choice:
If Lung abscess, empyema
PCN + Metronidazole
add sulfonamide for norcardia
Brain Abscesses: Empiric Abx of Choice:
dental sepsis
PCN + Metronidazole
Brain Abscesses: Empiric Abx of Choice:
Otitis Media or Mastoiditis
3rd gen ceph + metronidazole
Brain Abscesses: Empiric Abx of Choice:
sinusitis
3rd gen ceph + metronidazole
Brain Abscesses: Empiric Abx of Choice:
trauma/neurosurgery?
Vanc + 3rd/4th gen ceph (cover psuedomonas)
Brain Abscesses: Empiric Abx of Choice:
bacterial endocarditis
Vanc + gentamicin