Meningitis Flashcards
Define meningitis
Inflammation of the meninges (including the subarachnoid space or spinal fluid), the membranes that surround the brain and spinal cord
Define encephalitis
Inflammation of the brain
Define meningoencephalitis
Inflammation of the meninges and the brain
Define myelitis
Inflammation of the spinal cord
Define encephalomyelitis
Inflammation of both the brain and the spinal cord
What are the two types of meningitis?
Bacterial meningitis (clinical and laboratory evidence of meningeal inflammation with positive bacterial cultures)
Aseptic meningitis (meningeal inflammation with negative bacterial cultures, including viruses, atypical bacteria, and fungi, or there can be drug-induced causes, ie NSAIDs, sulfonamides, and carbamazepine)
Risk factors for meningitis?
Newborns (less than 2 months) or adults over age 50
Asplenia (functional or anatomic)
Anatomic defects
Immunocompromised (diabetes, cancer, alcoholism, organ transplantation, HIV/AIDS)
Genetic susceptibility
Who requires a CT scan?
Immunocompromised state History of CNS disease New onset seizure Papilledema Abnormal level of consciousness Focal neurologic deficit
What is required for diagnostic work-up?
History and physical exam (age, weight, allergy history, antibiotic history)
Identify risk factors that can determine therapy options
Blood cultures x 2 from 2 different sites
Lumbar puncture: gram stain, culture, and cell analysis
When should we not do a lumbar puncture?
Patients with elevated intracranial pressure because there is a risk for brain herniation and death
What is the most common bacteria that causes meningitis in adults?
Strep pneumoniae
What are the primary goals of treating meningitis?
Eradicate the infection
Amelioration of signs and symptoms
Prevent development of neurologic sequelae (Seizures, deafness, coma, death)
Treatment strategy for Penicillin susceptible S pneumoniae meningitis?
MIC would be less than 0.06 mcg/mL
Treatment: Penicillin G or Ampicillin
alternative: Cefotaxime, ceftriaxone, cefepime, or meropenem
Duration: 10-14 days
Treatment strategy for Penicillin reisistant S pneumoniae meningitis?
MIC would be greater than 0.06 mcg/mL
Vancomycin + cefotaxime or ceftriaxone
Alternative: Moxifloxacin
Duration: 10-14 days
Treatment strategy for Ceftriaxone resistant S pneumoniae meningitis?
MIC greater than 0.5 mcg/mL
Vancomycin + cefotaxime or ceftriaxone
Alternative: Moxifloxacin
Duration: 10-14 days
Is chemoprophylaxis for S pneumoniae meningitis recommended?
Chemoprophylaxis of those who come in contact with infectious person is not recommended
What does meningitis caused by strep pneumoniae lead to?
Can cause neurologic complications (ie coma/seizures)
What does meningitis caused by neisseria meningitidis lead to?
Can lead to deafness and transiently impaired eye movements
Is chemoprophylaxis for Neisseria meningitidis meningitis recommended?
Yes, those in close contact, ie individuals who frequently sleep and eat in the same dwelling.
Indicated for: Household contacts Daycare contacts Intimate contacts Healthcare workers with secretion contact
Treatment options for Neisseria meningitidis?
Penicillin G or ampicillin (Pen susceptible)
Cefotaxime or ceftriaxone (Pen resistant)
Alternative:
Cefotaxime or ceftriaxone
Meropenem or moxifloxacin (pen resistant?)
Duration 7-10 days
Prophylaxis options for Neisseria meningitidis?
Adults: Rifampin 600 mg every 12 hours for 2 days
Ceftriaxone 250 mg IM for 1 dose
Ciprofloxacin 500 mg PO for 1 dose
Children
Rifampin 10 mg/kg every 12 hours for 2 days in children 1 month and older
Ceftriaxone 125 mg IM x 1 dose for children younger than 12
Ciprofloxacin 250 mg PO x 1 dose for children over 12 years of age
What meningococcal vaccinations are available? Who are they recommended in?
Menactra, Menveo, Menhibrix
Recommend routine vaccination of children at age 11 through 12 years with booster at 16 years (don’t need booster in healthy individuals who got the vaccine at or after age 16)
High risk patients should also be vaccinated, and should be revaccinated every 5 years while at risk for meningococcal disease
What are the hallmarks of H influenzae type B meningitis?
Fever, decreased mental status, stick neck
How is H influenzae type B meningitis treated?
Empirically with Ceftriaxone or Cefotaxime until susceptibiltiies are back
B-lactamase negative: Ampicillin first choice, alternatives are cefoxatime, ceftriaxone, cefepime, or moxifloxacin
B-lactamase positive: Cefotaxime or ceftriaxone first choice, alternatives are cefepime or moxifloxacin
Duration 7-10 days
Prophylaxis for H Influenzae?
Rifampin 600 mg (20 mg/kg) daily for 4 days
Indicated in all individuals, including adults, in households with at least one unvaccinated or incompletely vaccinated child younger than 48 months
Any unvaccinated child between 12-48 months should receive one dose of the vaccine
Those between ages 2 and 11 months should be given 3 doses of the vaccine
Individuals fully vaccinated are not recommended to receive prophylaxis
Describe H influenzae vaccination schedule?
3-4 dose series, depending on formulation
Given at 2, 4, 6 months (primary) and 12-15 months (booster)
One dose may be given to patients over 5 years old with sickle cell, asplenia, or immunocompromising conditions
What role does dexamthasone play in menigitis treatment?
Death of bacteria can cause leakage of antigenic compounds; corticosteroids can inhibit the production of TNF and IL-1, both poent proinflammatory cytokines
Biggest impact is decreased incidence of neurologic sequelae (ie hearing loss), some mortality benefit
Mostly used in H influenzae and S pneumoniae
Biggest concern is reduced penetration of antibiotics
Other concerns: GI bleeding, hyperglycemia
In what pts do we give dexamethasone?
Adults should be given for pneumococcal meningitis
Children:
- Given to children with H influenzae
- Considered in children with S pneumoniae
- Should NOT be used in neonates or any infant less than 6 weeks old
Dose: 0.15 mg/kg or 10 mg every 6 hours x 4 days
Alternative: 0.15 mg/kg or 10 mg every 6 hours for 2 days or 0.4 mg/kg every 2 hours for 2 days
First dose given 10-20 minutes prior to first antibiotic use
Meningitis 1
JW is a 67 year old male who presents to the emergency department with fever (102.5 F), headache, and neck stiffness that has been bothering him for 2 days. PMH: Hypertension, hyperlipidemia. Allergies: NKDA, Weight 65 kg, Height: 5¶6´WBC: 17,600 cells/mm3, Serum creatinine: 1 mg/dL. Based on this patient’s risk factors, which of the following pathogens is more likely to cause his infection? Original Order: 26 ᅞ
A: Streptococcus agalactiae (Group B) ᅞ
B: Haemophilus influenzae type B ᅞ
C: Neisseria meningitidis ᅚ
D: Listeria monocytogenes
D: Listeria monocytogenes
Rationale: Answer: D. Listeria is most likely to occur in neonates, adults over 50, and immunocompromised. Group B Strep and H. influenzae are more common in children less than 2 years of age. Neisseria generally occurs in younger patients (1 mon to 50) and patients with immunocompromising conditions. 0/2.
AO is a 1 week-old female neonate who was admitted 3 days ago with bacterial meningitis and started on appropriate empiric antimicrobial therapy. Cultures from the lumbar puncture are now growing Listeria monocytogenes. Allergies: NKDA. Which of the following is the MOST appropriate antimicrobial agent for streamlining AO‘s therapy?
A:Cefotaximeᅚ
B:Ampicillinᅞ
C:Vancomycinᅞ
D:Trimethoprim-sulfamethoxazole
B:Ampicillinᅞ
Rationale: Answer: B. Ampicillin is the drug of choice for Listeria meningitis. Cefotaxime and vancomycin are not active against Listeria. Trimethoprim-sulfamethoxazole is considered an alternative option but is not first line, especially in a neonate
KS is a 40 year old male who presents to the ER with fever, headache, and neck stiffness.
Labs: WBC: 22,500 cell/mm3, Serum creatinine: 0.9 mg/dL. Allergies: NKDA. Weight: 70 kg. Height: 5’7”. The lumbar puncture was just drawn and sent to the lab but is still pending.
The ER physician has consulted pharmacy to assist with selecting and dosing antibiotics for empiric therapy of suspected bacterial meningitis. Which of the following regimens is MOST appropriate for KS?
A: Vancomycin 1000 mg IV every 12 hours + Ceftriaxone 1 gram IV every 24 hours
B: Ampicillin 2 grams IV every 4 hours + Cefotaxime 2 grams IV every 4 hours + Vancomycin 1500 mg IV load, followed by 1250 mg IV every 12 hours
C: Ceftriaxone 2 gram IV every 12 hours
D: Ceftriaxone 2 grams IV every 12 hours + Vancomycin 1500 mg IV load, followed by 1250 mg every 12 hours
D: Ceftriaxone 2 grams IV every 12 hours + Vancomycin 1500 mg IV load, followed by 1250 mg every 12 hours
Rationale: Answer: D. This patient is at risk for Streptococcus pneumoniae and Neisseria meningitidis and requires empiric coverage with vancomycin and a 3rd generation cephalosporin. A is incorrect because these are the wrong doses for meningitis. B is incorrect because ampicillin is not needed and is excessive therapy, this patient is not at risk for Listeria. C is incorrect because she needs empiric coverage for S. pneumoniae and N. meningitides until cultures and sensitivities come back, Vancomycin is missing.
