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Central Nervous System Infection – VASP

Bacterial Meningitis


  • Blood cultures prior to antibiotics if possible
  • Head CT pre-LP, only if: Immunocompromised, hx of CNS diseases (shunts, trauma, tumors), papilledema on exam or FND, AMS, or new onset seizure.
  • If there is a delay in obtaining head CT or LP, DO NOT delay antibiotics.
  • Lumbar puncture (See Procedures Section):
    • Obtain: Opening pressure, cell count + differential, glucose, protein, bacterial culture
    • Send an extra tube or two of CSF to the lab, if possible, to be frozen in case extra testing is needed (Order ‘Miscellaneous test’ and for test name put “Please freeze CSF in virology;” reference lab: VUMC, specimen type: CSF)
    • Additional studies to consider in select pts: HSV 1, 2 PCR (NOT antibodies), VZV PCR, VDRL, Crypto Ag, fungal and/or AFB cultures, MTB PCR, West Nile Virus Ab, Enterovirus PCR, Histoplasma Ag, or Biofire Meningitis/Encephalitis Panel. These should not be performed routinely on all pts and consult ID where management questions exist.
    • If Biofire Meningitis/Encephalitis Panel is performed, double check what is included to avoid sending duplicate individual tests (ie HSV, VZV, enterovirus, etc.) A negative cryptococcus on Biofire does not exclude disease (CSF Crypto Ag is more sensitive)


  • Antibiotics as soon as possible
    • Ceftriaxone 2g IV q12h + Vancomycin, adjusted for renal function
    • Piperacillin-tazobactam cannot be used due to poor CNS penetration
    • IV ampicillin 2g q4h for optional coverage of Listeria for immunocompromised pts, pregnant women, or age >50 (adjust based on renal function)
    • IV acyclovir 10 mg/kg (based on adjusted body weight) q8h, if suspected HSV or VZV meningitis, make sure to run with adequate pre-hydration with NS
    • Consider empiric PO/IV doxycycline 100mg BID if tick-borne illness is suspected
  • Steroids: IDSA guidelines-steroids (dexamethasone 0.15 mg/kg q6h) should be given 10-20 minutes before the first dose of abx, or at the same time, in pts with suspected bacterial meningitis. IF pneumococcus is isolated, continue IV steroids for 2-4 days; otherwise, can discontinue
  • ID consultation: Duration should be guided by ID and varies based on organism recovered



  • The presence or absence of normal brain function/cognition is the important distinguishing clinical feature between encephalitis and meningitis


  • MRI more sensitive that CT, although imaging may or may not demonstrate abnormal radiographic findings in pts with encephalitis
  • LP – similar studies as for meningitis (see above) + BioFire MEP for ALL pts


  • Acyclovir 10mg/kg IV q8hr (based on adjusted body weight), consideration of antibacterial therapy if unable to conclusively exclude a bacterial meningitis, consideration of doxycycline if tick-borne infection is on the differential, and further treatment as guided by ID
  • ID consult is strongly encouraged for all pts with suspected encephalitis

Brain Abscess


  • Consult: Neurosurgery and ID
  • Blood Cultures, HIV testing in any pt with a brain lesion
  • Empiric antibiotics:
    • IV Vancomycin (dose per PK) + ceftriaxone 2g IV q12h + metronidazole 500mg IV/PO q6h
    • If concern for extension from otitis externa, use an antipseudomonal cephalosporin (cefepime 2g IV Q8h) instead of ceftriaxone
    • Brain abscesses generally polymicrobial, thus broad-spectrum antibiotics indicated
  • Aminoglycosides, macrolides, tetracyclines (e.g. doxycycline), clindamycin, beta-lactam/beta-lactamase combinations (e.g., Zosyn) and 1st-generation cephalosporins (e.g., cefazolin) should NOT be used as they do not cross BBB at high concentration.
  • Antibiotic Duration: based on surgical drainage and ID guidance

Epidural Abscess


  • If spinal lesion, consult ‘Spine surgery’ and it will be directed to Ortho-Spine or Neurosurgery, depending on who is on call.
  • Abx should be started as soon as the diagnosis of epidural abscess is suspected, immediately following the collection of two sets of blood cultures
    • Vancomycin 15-20mg/kg IV q8-12h (adjusted for renal function) + ceftriaxone 2g IV q24h (or q12hr if there is secondary meningitis)
    • Use cefepime 2g IV q8h instead of ceftriaxone if concern for Pseudomonas
  • ID consult is strongly encouraged and they will guide duration