Meningitis - Block 2 Flashcards
What is meningitis?
Inflammation of the subarachnoid space or spinal fluid
What are the characteristics of normal CSF?
- Clear protein content <50 mg/dL
- WBC <5
- Lack of antibodies or complements
- BBB is tightly joined by capillary endothelial cells
What are the 4 processes of bacterial meningitis?
- Mucosal colonization and bacterial invasio of the CNS
- Bacterial replication
- Inflammation from bacterial cell lysis -> ativating inflammatory pathway -> increase permeability of BBB by vasodilation
- Neurological damage -> increase intracranial pressure and cerebral edema
What is the meningitis triad?
- Fever
- Nuchal rigidity
- ALtered mental status
What are the presentations of meningitis apart from the triad?
- Chills
- Fever
- Photophobia
- Kerning/Brudzinski
- Abnormal CSF chem
2 of the following
1. Fever
2. Nuchal rigidity
3. ALtered mental status
4. Severe HA
What are the common pathogens associated with meningitis?
- S. pneumoniae
- Group B strep (agalactiae)
- N. men.
- H flu
- Listeria
- G-
- Staph spp
- HSV
What are the RF of meningitis?
- Age with immune decline
- Large communal groups
- Traveling in areas o high prevalence
What are the common causes of CA bacterial meningitis? How can infection be prevented?
Strep. pneumoniae -> Prevnar 20
Strep. agalactiae
Neisseria -> Meningococcal conjugate vaccine
H. Flu -> Hib vac
Listeria
What are the diagnostic tools for meningitis?
Lab:
* CSF: Culture sensitivities (gold standard), Gram stain, PCR (Biofire)
* Blood culture
Imaging:
* MRI
* Computer tomography
How do we test CSF?
Lumbar puncture
* CSF and blood culture is taken before ABX
* If puncture is delayed still intiate ABX immediately
What are the objective findings of bacterial meningitis?
WBC: 1000-5000
Neutrophils
Elevated proteins
Low glucose (bacteria is using it)
What ABX cross CNS?
- Lipophillic
- Noncharged
- Small
- Low PPB
What are ABX properties that should be considered?
- -cidal
- definitive
- No high resistant empiric coverage
- Avoid ABX that worsen CNS sx -> Merrem causes sz
Drug that targets Listeria?
Ampicillin
Drugs that target GBS?
Ampicillin + 3rd gen or AG
Vanc + 3rd gen
Drugs that target Strep. pneumoniae?
Vanc + 3rd gen
Drugs that cover GNR?
3rd gen (Ceftriazone and Cefotaxime)