Therapeutics - Meningitis Flashcards
Where do CNS infections usually originate from?
What is the definition of meningitis?
- Ear or RTI
- Inflammation of meninges
Sx of Meningitis
2 of following:
- fever
- h/a
- stiff neck
- drowsiness, confusion
Additional:
- photophobia
- seizures, focal neurological signs
Most likely pathogens in:
-Newborn (<1 month)
- Group B strep
- Ecoli
- Enterobactericiae
- L. monocytogenes
Most likely pathogen in:
Infants (1-3 months)
Group B strep
E.coli
L. monocytogenes
Most likely pathogens in:
Children >3 months
Adults <50 years
S. pneumoniae
N. meningitidis
H. influenza if incomplete/no vaccination
Most likely pathogens in: Adults >50 years Immunocompromised Debilitated, Alcoholism Pregnancy
S. pneumoniae
L. monocytogenes
N. meningitidis
Enterobactericiae
Why is H. influenzae not such a big player in meningitis anymore?
-Hib type b vaccine have dramatically reduced meningitis rates due to H. influenzae
Dx: Hx and physical exam
- fever, stick neck, h/a, photophobia, drowsiness/confusion
- in small baby: poor feeding, lethargy, possible bulging fontanels
- Positive Brudzinki’s and Kernig’s sign (may beabsent in children)
- in meningococcal disease: rash, petechiae, purpuric lesions; aggressiveness
What is needed for diagnosis?
- hx and physical
- blood culture, PCR
- Routine blood chemistry, including serum glucose
- Spinal tab: CSF C+S and PCR
- CT of head if suspect increased intracranial pressure
Meningococcal Meningitis:
- Occur in what populations mostly?
- What are the 4 serogroups responsible for majority of cases
- Type of progression?
- Prognosis?
- Children <5 years and young adults
- A and C in epidemics; B sporadic and most common now; Y in sporadic cases
- Rapidly progression
- 50% mortality rate
Sequelae of Meningococcal Disease?
-Cranial nerve dysfunction leading to impaired ocular movements and deafness
-Disseminated intravascular coagulation (DIC): infarction of adrenals and renal cortex; thrombosis - loss of limbs; pulmonary microvascular thrombosis; shock and death
-Unique immune reaction 10-14 days after onset: fever, arthritis, pericarditis
(USE NSAIDS FOR THESE)
-Seizures and coma uncommon
Pneumococcal Meningitis
- Differences b/t this and meningococcal?
- Prognosis?
- Residual defects?
- Coma and seizures more common
- Bacteremia is less common
- Extremely high mortality 30-60%
- Hearing loss, seizures, hemiparesis (one-sided weakness)
What response to meningitis is responsible for the high morbidity and mortality? Why does this happen?
Inflammatory response, including IL-1 and TNF-alpha (pro-inflammatory cytokines)
Due to release of bacterial cell wall components:
G-: LPS, Lipid A
G+: (lipo)teichoic acid, peptidoglycan
What physiological response does an inflammatory response actually do?
- increased BBB permeability
- cerebral edema and intracranial pressure
- altered cerebral blood flow (lose consciousness)
- cerebral vasculitis, thrombosis
- Increased CSF protein and reduced CSF glucose
What drug can be used to help with the inflammatory response?
when is it given?
In what population has there been shown evidence of improved outcomes? No improved outcome?
Dexamethasone
Before or with abx
Adults with Pneumococcal meningitis and children >1 month with H. influenzae meningitis (decreased hearing loss).
No improved outcome in neonates, in H. influenzae or meningococcal infections.
