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.
Empiric Treatment in:
NEWBORN <1 MONTH
CHILDREN >1 MONTHS
Newborn:
Ampicillin+Gentamicin/cefotaxime
NO DEXAMETHASONE
Children:
Ceftriaxone + Vanco
Timing depends on bacterial pathogen
If severe pen allergy: switch ceftriaxone to chloramphenical
DEXAMETHASONE given before or with abx x2 days
Empiric Treatment in:
ADULTS
Ceftriaxone + Vancomycin
Pen allergy: switch ceftriaxone with chloramphenical
DEXAMETHASONE: before abx only
Prophylaxis of contacts is required with what type of meningitis?
Who are considered “close contacts”?
Prophylaxis abx
Meningococcal meningitis
Close contacts:
- household contacts
- childcare facility
- anyone sharing or contact with saliva in last 7 days, including medical personnel
- Rifampin is first line
- Ciprofloxacin (if taking OC or other interactions)
- ceftriaxone
What are some Prophylaxis vaccines used in group residences ex. nursing homes?
Monovalent Group C meningococcal conjugate Vaccine
Multivalent A, C, Y, W-135 vaccine (now available as conjugate)
Group B available but not used routinely
What is the concern of using dexamethasone with vancomycin? should it still be used?
Concern that with reduction of inflammation, vanco will not cross BBB as efficiently
Yes, should still be used
In pneumococcal menigitidis that is resistant to 3rd gen cephalosporins, what should you use and why?
Vancomycin and cefotaxime
-synergistic effects, even when resistant to cefotaxime
PLUS Rifampin
-in case vancomycin doesn’t cross BBB efficiently due to dexamethasone
