CNS Infection

Central Nervous System Infection – VASP

Meningitis

 

Evaluation

  • 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):
    • 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. These should not be performed routinely on all patients and consult ID where management questions exist.
    • If BioFire is performed, double check what is included to avoid sending duplicate individual tests (ie HSV, VZV, enterovirus, etc.)

 

Management

  • 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 patients, pregnant women, or age >50 (adjust based on renal function)
    • IV acyclovir 10 mg/kg 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: Based on IDSA guidelines and a recent meta-analysis, steroids (Dexamethasone 0.15 mg/kg q6h) should be given about 10-20 minutes before the first dose of antibiotics, or at the same time, in patients with suspected bacterial meningitis. IF pneumococcus is isolated, continue IV steroids for 2-4 days; otherwise, can d/c
  • ID consultation: Duration should be guided by ID and varies based on organism recovered

 

 

Encephalitis

Background

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

 

Evaluation

  • MRI more sensitive that CT, although imaging may or may not demonstrate abnormal radiographic findings in patients with encephalitis
  • LP – similar studies as for meningitis (see above) + BioFire MEP for ALL pts
  • Consider ID consult prior to LP to assess what additional tests should be ordered.

 

Management

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

 

Brain Abscess

Evaluation/Management

  • Consult: Neurosurgery and ID
  • Blood Cultures, HIV testing in any patient with a brain lesion
  • Empiric antibiotics:
    • IV Vancomycin (target trough 15 - 20 mcg/mL) + 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 Infectious Diseases guidance

 

 

Epidural Abscess

Management

  • If spinal lesion, consult ‘Spine surgery’ and it will be directed to Ortho-Spine or Neurosurgery, depending on who is on call.
  • Antibiotics 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