Lecture 8 - CNS Infections Flashcards
CSF Shunts
essentially tube with valve implanted in skull and you drain the fluid to control the pressure in brain to somewhere else in the body
Meningitis
Inflammation of members of the spinal cord and brain, particularly leptomeninges
based by bacteria, viruses, meds, fungus
Encephalitis
inflammation of the brain
caused by viruses and bacteria
Transmission & Risk Factors of Meningitis
- Spread through blood
- Direct entry leading to contiguous spread
RF: immunosuppression, cig smoking, inc risk in prisons/dorms/barracks
top 5 bacteria for Meningitis
- Strep pneum
- Group B Strep
- N. meningitis
- H. Influ
- Listeria monocytogenes
top 5 bacteria for Meningitis > 60yrs old
- S. pneu
- L. mono
- N.meningitis
- Group B strep
- H. influ
Things that can cause Aseptic Meningitis?
Viral = HSV2, Varicella, HIV, flu
Meds = NSAIDs, sulfamethoxazole, aminopenicillins, carbamazepine, lamotrigine, ranitidine
Fungal
Parasites
Tuberculosis
Syphilis
Aseptic Meningitis means that….
from sample of CSF we cant find where its from
Pathophysiology of Meningitis
- Strep pneumo makes a protease that lets it go undetected by immune system.
- Bacteria can live in bloodstream, and it binds to receptors that allows it to pass through.
- Strep Pneumo, prevents interaction w/ C3b bc its encapsulated**
- Due to inflammation, tight junctions in BBB start to break apart
- this allows bacteria to pass through and into brain & CSF
- CSF has little to defend against bacteria
CSF markers of Meningitis
Increase CSF protein
Decreased CSF glucose
Increase CSF Lactate
Classic “Triad” for Meningitis
Fever**
Nuchal Rigidity**
Altered Mental Status**
Headache
Physical exams findings for Meningitis
Brudzinski Sign
Kernig’s Sign
Jolt accentuation
CSF Analysis from Lumbar Puncture
Glucose, protein, WBC, and lactate
Gram stain, culture, susceptibility
What sorts of values are we looking for in Bacterial Meningitis
Opening pressure > 250
Glucose % < 40% (Dec)
Protein > 200 (elevated)
WBC > 1000 (80-90% Neutrophils)
Lactate > 3.5
two barriers for medications when dealing with Meningitis
BBB and Blood-CSF barrier
To cross BBB/ Blood-CSF barrier, we need….
High Lipophilicity
Low degree of ionization
Small molecule weight
Low protein binding
Meningitis Goals of Therpy
** Prevention / Vaccines
eradicate infeciton
improve signs/symptoms
reduce morbidity and mortality
Empiric therapy < 1 month old common pathogens
Group B strep
E.coli
Klebsiella
Enterobacter
L.monocytogenes
Empiric therapy < 1 month treatment
Ampicillin + cefotaxime**/Ceftazidime/cefepime = due to shortage
Ampicillin + AG (Genta/Tobra)
Empiric therapy 1-23 month old common pathogens
S. pneum
N. Meningitidis
H. influ
S. agalactiae
E. coli
Empiric therapy 1-23 month old treatment
Vanco + 3 Gen Ceph (Ceftriaxone or cefotaxime)
Why give 2 things that cover gram +?
Ceftriaxone-nonsusceptible strains of S.pneum occur about 10% of the time
Empiric therapy 2-50 yrs old common pathogens
S. pneumoniae
N. Meningitidis
Empiric therapy 2-50 yrs old treatments
Vancomycin + 3 Gen ceph (Ceftriaxone or Cefotaxime)
Empiric therapy > 50 yrs old common pathogens
S. pneum
N. meningitides
L. mono
Aerobic GNR
Empiric therapy > 50yrs old treatments
Vancomycin + 3 Gen ceph (Ceftriaxone or Cefotaxime) + ampicillin
Antibiotic Dosing considerations
tend to be dosed higher than usual
Vancomycin Meningitis dosing
15-20mg/kg Q8-12hrs
monitoring doing troughs or AUC
Big issue with Pneumococcal Meningitis?
Hearing loss
Pneumococcal Meningitis (PCN susceptible) TXM
PCN G 4mil units IV q4h or Ampicillin 2g IV q4h
alternative: cefotaxime, ceftriaxone, cefepime, meropenem
Pneumococcal Meningitis (PCN resistant) TXM
Vancomycin (15-20mg/L) + ceftriaxone 2g q12h/cefotaxime 2g IV q4-6h
Alternative: moxifloxacin
Meningococcal Meningitis (PCN Susceptible) Txm
PCN G 4mil units IV q4h or Ampicillin 2g IV q4h
Alternative: 3rd Gen Ceph (Cefotaxime/ceftriaxone) chloramphenicol
Meningococcal Meningitis (PCN resistant) Txm
Ceftriaxone 2g q12h or cefotaxime 2g IV q4-6h
Alternative: moxifloxacin, meropenem, chloramphenicol
N. Meningitidis Chemoprophylaxis close contact definition
ppl within 3 feet of patient for >8hrs during 7 days before and 24hrs after starting ABX
N. Meningitidis Chemoprohylaxis txm
Essential Rifampin for everyone in different doses
Ceftriaxone preferred in pregnant
H. Flu type B (B-lactamages neg) Txm
Ampiclin 2g IV q4h
H.Flu type B (B-lactamase pos) Txm
Cefotaxime 2g q4-6h or ceftriaxone 2g IV q12h
H.Flu type B chemoprophylaxis
Rifampin in 4 doses
unvaccinated close contacts
Listeria Monocytogenes TXM
PCN G 4mil units IV q4h + gent or Ampicillin 2g IV q4h + gent
Group B strep TXM
PCN G 4mil units IV q4h or Ampicillin 2g IV q4h
Group B Strep chemoprophylaxis
pregnant in labor should receive PCN or Ampicillin if…
GBS carrier
H/x of GBS bacteriuria
Prev delivery of infant w/ GBS
S. pneumoniae length of therapy
10-14 days
N. meningitides or H.influ length of therapy
7-10 day, may extend to 14 days
GBS, S.aureus length of therapy
14-21 days
Enterobacteraceae, P.aeruginosa length of therapy
21 days
L. monocytogenes length of therapy
> 21 days
when to consider outpatient ABX treatment for meningitis?
can do after 7 days if….
low risk of neurologic complications
able to adhere w/ close monitoring and follow-up
Children advantages with steroid treatment
less hearing loss w/ H.influ infection
Adult advantages with steroid treatment
dec mortality w/ S.pneum
Disadvanages of steroid treatment
dec ABX pen, so give before or w/ 1st dose (within 10-20min)
guileless recommend starting for all adults w/ suspected bacterial meningitis
Encephalitis symptoms
Altered mental status
Stupor
Seizures more common
Common causes of Encephalitis
HSV1 in adults
HSV2 in neonates
