Bacterial meningitis Flashcards
(44 cards)
risk factors fo meningitis
extremes in age <1 and >65
–infants at greater risk
unvaccinated individuals
anatomical or functional asplenia
pregnancy
what is bacterial meningitis
inflammation/ infection affecting the meninges with positive bacterial structures
causative pathogens for ages 2-50
s.pneumoniae
n.meninditidis
encapsulated pathogens
s.pneumoniae (GP)
n.meninditidis (GN)
h. influenza (GN)
virulence factor
polysaccharide encapsulated organisms
risk factors for listeria monocytogenes (GP) virulence
extreme age
alcoholism
malignancy
use of chronic corticosteroids
immunocompromised
diabetes
cirrhosis
pregnancy
CKD
unpasturized milk/cheese, raw meat
pathogenesis of bacterial meningitis
s.pneumoniae
n.meninditidis
h. influenza
colonize the nasopharynx –> massive production of CSF cytokines and chemookines
signs and symptoms of meningitis
classic triad**
–fever
–nuchal rigidity ( stiff neck)
–altered mental status
headache
photophobia
N/V
diffuse petechiaial rash
focal neurological defects
–positive brudzinkis sign
–positive kerning’s sign
signs and symptoms of encephalitis
fever
profound altered mental status **
–confusion
–behavioral abnormalities
–hallucination/psycosis
headache
photophobia
N/A
focal or generalized seizures**
focal neurologic disturbances**
brudzinski sign
severe neck stiffness causes patients hip and knee to flex when the neck is flexed
kernigs sign
severe stiffness of the hamstring causes an inability to straighten leg when the hip is flexed to a 90 degree angle
neonate/ infant presentation
changes in activity and poor feeding
vommiting, irritability, high-pitched crying
positive brudzinski and or kernigs sign
children presentation
similar to adultt ( neck stiffness, headache)
elderly presentation
lack the signs and symptoms of younger adults
– less notable neck stiffness and headache
altered mental status and focal neurological deficits - more common
diagnostic work up / tools
lumbar puncture
-determine opening pressure
-CSF analysis, gram stain, culture
-viral/bacterial polymerase chain reaction
lumbar puncture
insertion of a needle into the subarachnoid space in the lumbar area of the spine to obtain cerebrospinal fluid
normal RBS , 5x10^6
CSF interpretation of bacterial meningitis
CSF appearance: cloudy and turbid
opening pressure: >=250
CSF WBC: >=1000
dominate cell type: neutrophils
CSF protein: high
CSF glucose: low
how long may it take for csf culture
48-72 hrs
no delay in performance of Lumbar puncture
obtain 2 sets of blood cx + perform LP
initiate dexamethasone + antimicrobial therapy
delay in performance of lumbar puncture
obtain 2 sets of blood cx
initiate dexamethasone + antimicrobial therapy
perform head CT/MRI scan +?_ LP
risks of dexamethasone
potential to reduce abx CSF penetration
poor antibiotic CSF con + treatment failure
use of dexamethasone in pediatrics
insufficient data, not significant protection
when is the first dose of dexamethasone recommended for administration
10-20 minutes before or at the time of antimicrobial administration
empiric treatment for 2-50 years for s. pneumonia and n. meningitis
vancomycin + ceftriaxone
