csf how certain can we be
Download
Skip this Video
Download Presentation
CSF: How certain can we be?

Loading in 2 Seconds...

play fullscreen
1 / 15

CSF: How certain can we be? - PowerPoint PPT Presentation


  • 100 Views
  • Uploaded on

CSF: How certain can we be?. Meira Louis PGY1. Objectives. Present a published case highlighting the difficulties in CSF diagnosis Understand the objective evidence for the tests ordered on CSF Understand where clinical judgement falls in the spectrum of certainty. Sheila. PMX:

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' CSF: How certain can we be?' - pearly


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
objectives
Objectives
  • Present a published case highlighting the difficulties in CSF diagnosis
  • Understand the objective evidence for the tests ordered on CSF
  • Understand where clinical judgement falls in the spectrum of certainty
sheila
Sheila
  • PMX:
    • Childhood asthma
    • Hyperthyroidism
  • Meds:
    • None

21yo female

1 day history:

  • non-specific lethargy
  • Fever and rigors
  • Generalized headache
  • Nausea, vomiting

Huynh et al, 2007

slide4

On exam:

    • Vitals: 38°C
    • Alert, oriented
    • Normal neuro
  • Bloodwork
    • WBC: 19.5
    • CRP: 185
    • Lytes, LFTs, glucose
  • Imaging:
    • Chest X-ray
    • Urinalysis
    • CT head
csf for what
CSF – for what?
  • Cell count
  • Gram’s Stain
  • Turbidity
  • Xanthochromia
  • Glucose
  • Protein
  • India Ink
  • Cryptococcal Antigen
  • Lactic Acid
  • Bacterial Antigen tests
  • Acid Fast Stain
sheila s csf
Sheila’s CSF
  • Clear and colourless
  • Protein: 0.38 mg/dL
  • Glucose: 3.6 mmol/L
  • 12x106 RBC
  • 1x106 WBC (all mononuclear)
  • Negative gram stain
what would you do
What would you do?
  • What’s your diagnosis?
  • How confident are you?
  • How confident should you be?
cell count and differential
Cell Count and Differential
  • How many leuks are too many leuks?
  • Does it matter what kind?
    • Monomorphic vs polymorphic
    • lymphocytosis
  • Does prior abx change your cell count?

Thomson et al, 2001.; Van de Beek, 2004.

what happens with a traumatic tap
What happens with a traumatic tap?

Predicted WBC = CSF RBC x serum WBC

serum RBC

  • If WBC was more than 10x normal was 48% predictive of bacterial meningitis
  • If less than 10x was 99% predictive of it NOT being meningitis

Mayefsky et al. 1987

glucose
Glucose
  • Hypoglycorrhachia
  • If normal serum glucose:
    • Ratio of CSF:serum is 0.6:1
    • Abnormal when less than 0.5
  • If elevated serum glucose:
    • Ratio of CSF:serum is 0.4:1
    • Abnormal when less than 0.3
protein
Protein
  • Normal range in CSF: 15-45 mg/dL
    • Greater than 150 is probably bacterial
    • Greater than 1000 should suggest fungal
  • Other causes?
    • Any meningitis
    • Subarachnoids
    • CNS vasculitis
    • Syphilis
    • Viral encephalitis
    • neoplasms
gram stain
Gram Stain

What’s the sensitivity for bacteria?

All common etiologies-no previous antibiotics 75-90%

All common etiologies-antimicrobial therapy prior to LP 40-60%

Streptococcus pneumoniae 90%

Neisseria meningitidis 75%

Haemophilus influenzae 86%

Listeria monocytogenes <50%

Gram-negative bacilli 50%

Gray et al, 1992

other tests
Other tests

Lactic Acid

  • Non-specific
  • Elevations over 35 mg/dL may indicate bacterial meningitis
  • Lactate may rise before glucose drops

Serum Procalcitonin

  • Very sensitive
  • Not available for up to 24 hours
back to the case
Back to the case…
  • The following morning:
    • Diplopia, worsening headache
    • Temp increase to 40°C
    • GCS of 9
    • No rash, no nuchal rigidity, no focal neuro
  • Repeat CT scan with contrast
  • IV ceftriaxone, gentamicin, and acyclovir were started
  • Blood and CSF came back positive for N. meningitidis
ad