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CSF analysis

OVERVIEW

  • CSF = cerebrospinal fluid
csf cerebrospinal fluid analysis

THINGS TO PUT ON THE FORM

  • gram stain
  • microscopy
  • culture
  • xanthochromia
  • WCC
  • RCC
  • protein
  • oligoclonal bands
  • extended culture
  • cryptoccal antigen and Indian ink stain
  • ZN stain for acid fast bacilli
  • PCR for enterovirus and HSV
  • cytology

APPEARANCE

  • normally clear
  • turbid with infection
  • blood stained with SAH and traumatic taps
  • yellow with xanthochromia (this takes 6-12 hours to develop after blood enters CSF)

WCC

  • normally scant monocytes
  • in traumatic tap classically taught to expect 1 WCC : 500 RCC (if normal in peripheral cell counts) but this is not reliable
  • polymorphonuclear leukocytosis: bacterial infection
  • lymphocytosis: viral, TB, cryptococcal and listerial infections
  • mixed lymphocytosis/monocytosis in GBS and status epilepticus

RCC

  • increased in traumatic tap and SAH

PROTEIN

  • increased in infection: Tb > bacterial > viral
  • increased in GBS, vasculitis and sarcoidosis
  • oligoclonal bands in multiple sclerosis
  • increased in CNS inflammation (including CSF drains and blood in CSF)

GLUCOSE

  • normally at least 75% serum glucose
  • less than half serum in infections (bacterial, Tb and fungal infections) and vasculitis and sarcoidosis

OTHER FINDINGS

  • xanthochromic index with spectrophotometry (in SAH)
  • extended culture (Listeria, Cryptococcus)
  • India Ink stain for cryptococcus
  • ZN stain for acid fast bacilli
  • PCR for enterovirus and HSV
  • cytology

Meningitis

  • Infective
    • Bacterial
    • Aseptic – Viral, TB, Fungi, Parasites
  • Non-infective
    • Malignancy
    • Auto-immune
  • Bacterial:
    • Neonatal (<3/12)
      • Gram negative (E coli)(Pseudomonas), Listeria, Group B strep, Coag –ve staphylococcus
    • 3/12 to 15 years
      • Neiserria meningitidis, Pneumococcus (strep pneumonia), Haemophilus pneumonia
    • Adult > 15 years
      • N meningitidis, s. pneumonia, listeria, klebsiella, s. aureus
    • Elderly
      • Gram negatives predominate
    • Immunocompromised
      • Complement deficiency – Neiserria
      • Humoral or asplenic – Neiserria, enterovirus
      • Sickle cell disease – Capsulated organisms
  • Aseptic meningitis (Generally accepted as mainly viral meningitis)
    • Lymphocytosis, variable protein elevation and normal glucose
    • Viral
      • Echovirus, Enterovirus, Mumps
      • HSV 1 + 2, CMV, VZV, EBV
    • Other
      • TB, Nocardia, Leptospira, Treponema
      • Fungi, rickettsia, parasites
      • Malignancy, auto-immune

Specific Risk Factors

  • Pneumococcus: (40%) – Otitis media, head injury, pneumonia, immunocompromised
  • N meningitidis: (30%) – Children and adolescents
  • Staphylococcus: Penetrating skull injury, ear or neuro operations
  • Fungal: HIV and organ transplant
  • Listeria: Extremes of age
  • H Influenzae: (3%)  – Head trauma with CSF leak, otitis, sinusitis, anatomical defects such as dermal sinus tracts
  • Anaerobes: Consider brain abscess, elderly
CCC 700 6

Critical Care

Compendium

…more CCC

Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.

After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.

He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE.  He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.

His one great achievement is being the father of three amazing children.

On Twitter, he is @precordialthump.

| INTENSIVE | RAGE | Resuscitology | SMACC

2 Comments

  1. Hi Chris,
    In the table, protein in TB CSF appears to be wrong. It should be 1-5, not 0.1-0.5 gm/L

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