Bacterial Meningitis

The inflammation of the outer layer of the brain, pia mater, arachnoid, and CSF filled subarachnoid space

Meningitis

Infection of brain parenchyma/tissue

Encephalitis

Infection of the spinal cord

Myelitis

Infection of the brain tissue and spinal cord

Encephalomyelitis

What BBB capillary characteristic prevents passive diffusion from intravascular space into brain parenchyma but becomes permeable once inflamed

Non-fenestrated

How is the Hematogenous (most common) method microbial spread into CNS

Bacteria attached to Nasopharyngeal epithelium

Breached mucosal barrier

What is the Contiguous method of microbial spread into CNS

Secondary to infections (ex. Otitis media, sinusitis, mastoiditis)

Secondary to invasion via trauma

What is the Nosocomial method of microbial spread into CNS

Contamination during surgery or lumbar puncture

What is the indication of elevated Neutrophils

Bacterial infection

Likely Pathogens in Bacterial Meningitis for Newborns - 1 month

S.agalactiae

Gram Neg. Enteric bacilli

Listeria monocytogenes

Likely Pathogens in Bacterial Meningitis for 1 month - 23 months

S.pneumoniae

N.meningitidis

S.agalactiae

H.influenza

Likely Pathogens in Bacterial Meningitis for 2-50 years

S.pneumoniae

N.meningitidis

Likely Pathogens in Bacterial Meningitis for > 50 yo

S.pneumoniae

N.meningitidis

Gram neg. Enteric bacilli

Listeria monocytogenes

Criteria for neuroimaging

>60 yo

CNS disease Hx

Immunocompromised

Recent seizure activity

Altered consciousness / focal neurologic deficit

Empiric therapy for newborns - 1 month

Ampicillin

PLUS

Aminoglycosides OR Cefotaxime

Empiric therapy for 1 month-24month old

Vancomycin

PLUS

Ceftriaxone OR Cefotaxime

Empiric therapy for 2-50 years

Vancomycin

PLUS

Ceftriaxone OR Cefotaxime

Empiric therapy for >50

Vancomycin + Ampicillin

PLUS

Ceftriaxone OR Cefotaxime

Drug classes that are Bactericidal

Beta Lactams

Vanco

Aminoglycosides

Fluoroquinolones

Daptomycin

Bactrim

Drug classes that are Bacteriostatic

Linezolid

Tetracyclines

Macrolides

Drugs with therapeutic CSF levels

Penicillins

3rd/4th gen IV Cephalosporins

Fluoroquinolones

Aztreonam

Vanco

Dapto

Sulfonamides

Lab values that indicate Meningitis

Increased WBC

Increased Protein

Decreased Glucose

Lab indications for Bacterial Meningitis

WBC (1000-5000 cells/mm³)

Neutrophils

Protein 100-500 mg/dL

glucose <40 mg/dL (<50% serum value)

Lab indications for Viral Meningitis

WBC (50-1000 cells/mm³)

Lymphocytes

Protein 30-150 mg/dL

Glucose normal at 45-80 mg/dL (50-60% serum value)

Rapid diagnostic tests to determine definitive therapy

PCR

Biofire

What additional additive therapy and dose is given if the patient has S. Pneumonia

Dexamethasone 0.15 mg/kg IV q6 given 10-20 minutes prior of Abx for 2-4 days

What organisms should receive 10-14 days of therapy

S. pneumoniae

Aerobic Gran Negative Rods (GNRs)

What organisms should receive 7-10 days of therapy

N. meningitidis

H. influenzae

What organisms should receive 21 or more days of therapy

Listeria monocytogenes

Aerobic GNRs

What antimicrobial options can be used for N. meningitidis

Penicillin G

Ampicillin IV

Ceftriaxone

What antimicrobial options can be used for H. influenzae

Ampicillin IV

Ceftriaxone

What antimicrobial options can be used for S. pneumoniae

Penicillin G

Ampicillin IV

Ceftriaxone

What antimicrobial options can be used for Aerobic GNRs

Ceftriaxone

Meropenem

Aztreonam

What antimicrobial options can be used for L. monocytogenes

Penicillin

Ampicillin IV

Bactrim

List of suspected organisms to cause Nosocomial meningitis

Staphylococcus aureus

Coagulase negative staphylococci

Aerobic gram neg bacilli (+ Pseudomonas aeruginosa)

Cutibacterium acnes

What Definitive antimicrobial options and DoT for MSSA

Nafcillin

What Definitive antimicrobial options and DoT for MRSA

Vanco or Dapto

10-14 days

What Definitive antimicrobial options and DoT for Coagulase neg staphylococci

Vanco or Dapto

10-14 days

What Definitive antimicrobial options and DoT for P. aeruginosa

Cefepime, Ceftazidime, or Meropenem

10-14-21 days

What Definitive antimicrobial options and DoT for

Enterobacter cloacae / Citrobacter freundii / Klebsiella aerogenes

Meropenem

10-14-21 days

What Definitive antimicrobial options and DoT other Enterobacterales

Ceftriaxone or Cefepime

10-14-21 days

What Definitive antimicrobial options and DoT for C. acnes

Ceftriaxone or Cefepime

10-14 days