CNS infections Flashcards
Barriers in the CNS
Blood-Brain Barrier–>5000x larger than BCSFB
Blood-CSF-Barrier
Characteristics of Abx for penetration
Lipophilic
Unionized
Un-protein bound (free drug)
Low molecular weight
Inflammatory CSF
With/without meningeal inflammation
Acyclovir, ganciclovir
Fluconazole, voriconazole
FQs
Linezolid
Metronidazole
TMP-SMX
With meningeal inflammation
Penicillins
3rd/4th gen cephalosporins
Aztreonam
Meropenem
Vancomycin
Colistin
Acute Bacterial Meningitis symptoms
Fever
HA, backache, nuchal rigidity, mental status change
Photophobia
Petechiae or pupura
Poor feeding habits (infants)
Acute Bacterial Meningitis diagnosis
CSF: 3 tubes via lumbar puncture
- elevated opening pressure (200-500 mm H2O)
CT/MRI:
- if papilledema, history of CNS, impaired consciousness
Empiric treatment for neonates (< 1 month)
Pathogens:
- S. pneumoniae
- S. agalactiae
- Listeria
- Neisseria
Treatment:
- Ampicillin + ceftriaxone (biliary slugging)
- Ampicillin + cefepime
- Ampicillin + aminoglycoside
Empiric treatment for infants (1-23 months)
Pathogens:
- S. pneumoniae
- S. agalactiae
- Neisseria
- Hemophilus
Treatment:
Vancomycin + ceftriaxone
Empiric treatment for children/adults (2-50 yr)
Pathogens:
- S. pneumoniae
- Neisseria
Treatment:
- Vancomycin + ceftriaxone
Empiric treatment for older adults ( > 50 yr)
Pathogens:
- S. pneumoniae
- Listeria
- Neisseria
Treatment:
- Vancomycin + ceftriaxone + ampicillin
S. pneumoniae–> gram + diplococci
Sensitive to penicillin
- penicillin
- ampicillin
Penicillin resistant
- ceftriaxone
Cephalosporin resistant
- vancomycin
Duration: 10-14 days
S. agalactiae
Ampicillin +/- gentamicin
Duration: 14-21 days
S. aureus
MSSA: nafcillin
MRSA: vancomycin
Duration: 14-21 days
Listeria
Ampicillin +/- gentamicin
Duration: 21 days
N. meningitidis
Penicillin
Ceftriaxone
Duration: 7 days
H. influenzae
BL -
- Ampicillin
BL +
- Ceftriaxone
Gram negative
Ceftriaxone
Cefepime
Duration: 21 days
Steroids
Indications: neurologic sequelae
Who? consider in children > 2 months with suspected meningitis or adult pneumococcal meningitis
Duration: 2-4 days
Viral encephalitis pathogens
Enterovirus: poliovirus
- transmission: fecal-oral
- when?: late summer, early fall
Arbovirus: West Nile, Colorado Tick
- transmission: mosquito and birds
- when?: late summer, early fall
HSV, VZV, CMV, HHV-6
Viral encephalitis treatment
Benign and self-limiting with full recovery in 7-10 days
- fluids, analgesics, antipyretics
HSV: Acyclovir 10-20 mg/kg q8h x 14-21 days
VZV: Acyclovir 10-15 mg/kg q8h x 10-14 days
CMV: Ganciclovir 5 mg/kg q12h x 14-21 days; combine with foscarnet if living with HIV
Normal CSF
WBC < 5
Differential negative
Protein < 50
Glucose 30-70
Bacterial CSF
WBC > 1000-5000
Differential > 80% neutrophils
Protein 40-150
Glucose < 30-70
Fungal CSF
WBC 10-500
Differential > 50% lymphs
Protein 40-150
Glucose < 30-70
Viral CSF
WBC 5-300
Differential > 50% lymphs
Protein 30-150
Glucose < 40-70
