Meningitis

Question 1

Meningitis Epidemiology

Answer 1

• Most caused by S. pneumoniae and N. meningitidis
• Surviving a gram “-“ bacilli meningitis has a 60% risk of developing a complication
• Can also be fungal, viral, mycobacteria, or parasitic in nature

Question 2

Meningitis Pathophysiology

Answer 2

• Mucosal colonization: fimbriae and polysaccharide are pathogenicity factors
• Survive intravascularly
• Invade meningeal and subarachnoid space invasion
• Cause blood barrier disruption

Question 3

Meningitis Adult Presentation

Answer 3

• Headache
• Fever
• Stiff neck
• Photophobia
• Altered mental status
• Obtundation
• Seizures
• Vomiting

Question 4

Meningitis Infant Presentation

Answer 4

• Irritability
• Altered sleep
• Vomiting
• High-pitched cry
• Decreased oral intake

Question 5

Meningitis Children Presentation

Answer 5

• Lethargy
• Confusion
• Somnolence

Question 6

Meningitis Signs

Answer 6

• Bilateral
• Inability to straighten leg when hip flexed 90 degrees
• Flexion of the neck causes hip/knee flexion
• Babinski sign (absent)

Question 7

Cerebrospinal Fluid

Answer 7

• Flows unidirectionally and increases in volume with age
• Normally clear, 50-60% serum glucose, pH 7.4, and <5 WBCs/mm3
• Used to diagnose meningitis

Question 8

Cerebrospinal Fluid + Bacterial

Answer 8

• WBC: 1,000-5,000
• > =80% neutrophilic
• Protein: 100-500
• Glucose: =<40
• CSF/serum ratio =<0.4

Question 9

Cerebrospinal Fluid + Fungal

Answer 9

• WBC: 40-400
• Mainly lymphocytic
• Protein: 30-150
• Glucose: 30-70

Question 10

Cerebrospinal Fluid + Viral

Answer 10

• WBC: 5-500
• Mainly lymphocytic
• Protein: 40-150
• Glucose: 30-70

Question 11

Diagnostic Methods

Answer 11

• CSF Evaluation: gram stain and culture
• Enzyme immunoassay for bacteria
• PCR for viruses, mycobacteria, and fungi

Question 12

Goals of Therapy

Answer 12

• Eradicate infection
• Ameliorate signs and symptoms of infection
• Prevent complications

Question 13

Meningitis Management

Answer 13

• EMPIRIC ABX
• Anti-inflammatory agents
• Fluids
• Electrolytes
• Antipyretics
• Analgesia

Question 14

Abx Requirements for Penetration

Answer 14

• Low molecular weight
• Non-ionized
• Low protein bound
• Lipophilic

Question 15

Empiric Therapy

Answer 15

• Use until age, allergies, and concurrent medical conditions are identified
• Should be initiated within 30 minutes of presentation, even without LP
• Should be continued for 48-72 hours until diagnosis of meningitis is ruled out
• Tailor therapy to organism/sensitivities once identified

Question 16

Meningitis Empiric Treatment + Adults

Answer 16

-Ceftriaxone
OR
-Cefotaxime
PLUS
-Vanco

Question 17

Listeria Monocytogenes

Answer 17

• Gram “+” bacilli or coccobacilli
• Increased rates with neonates/ elderly, and alcoholics
• Colonizes GI tract and penetrates gut lumen
• Often misidentified
• Add ampicillin in adults

Question 18

Dexamethasone

Answer 18

• Anti-inflammatory
• Inhibits pro-inflammatory cytokine production
• Improves CSF parameters
• May help reduce hearing loss
• Give before abx
• Increased risk of GI bleed and decreased abx penetration

Question 19

Children + Dexamethasone

Answer 19

• Benefits shown in H.influenzae and MAYBE S. pneumoniae
• Start before or at the same time as abx
• Given for 2-4 days

Question 20

Adults + Dexamethasone

Answer 20

• Start before abx
• Give for 4 days
• Only continue if S. pneumoniae is the offending agent

Question 21

Evaluation of Response

Answer 21

• Signs and symptoms
• Vital signs and cerebral dysfunction q4h for 72 hours
• CSF reculture, PCR if not responsive
• Identification/susceptibility usually takes 72 hours
• Individualize therapy after receiving results

Question 22

Treating N. Meningitis

Answer 22

• PCN MIC < 0.06: PCN G q4h (different dosing based on age)
• PCN MIC >= 0.12: Ceftriaxone or cefotaxime
• Duration: 7 days

Question 23

Contact Prophylaxis

Answer 23

• Recommended for close contacts and anyone directly exposed to patient secretions
• Administer ASAP, if 14 days post-contact, probably not helpful

Question 24

Prophylaxis Regimens

Answer 24

• Ceftriaxone IM for 1 dose
• Amount varies depending on if over or under 15 y.o.

Alternatives

• Rifampin given over 4 doses
• Dosing amount varies based on age

Question 25

Streptococcus Pneumoniae

Answer 25

• Gram “+” diplococci
• Most common causer in adults
• Seen commonly in children too

Question 26

S. Pneumoniae + Risk Factors

Answer 26

• Pneumonia
• Endocarditis
• Splenectomy
• Head trauma
• Alcoholism
• Sickle cell disease
• Bone marrow transplant

Question 27

S. Pneumoniae Treatment

Answer 27

• Continue dexamethasone for 4 total days
• Cefotaxime or Ceftriaxone can be used (dosing based on age)
• If PCN susceptible MIC < 0.06: switch to PCN
• If ceftriaxone/cefotaxime MIC >=1: Vanco + 3rd gen cephalosporin
• Duration: 10-14 days

Question 28

Treatment of H. Influenzae

Answer 28

• 30-40% of isolates produce B-lactamase
• B-lactamase negative: Ampicillin
• B-lactamase positive: Cefotaxime or Ceftriaxone
• Duration: 10 days

Question 29

H. Influenzae Prophylaxis

Answer 29

• Close contacts, nursing home residents, crowded confined populations
• Rifampin over 4 doses
• Individuals fully vaccinated and over 2 y.o. may not benefit from prophylaxis

Question 30

Listeria Treatment

Answer 30

• Ampicillin PLUS AMG
• Alternative: Bactrim
• Duration: 21 days