Csf how certain can we be
This presentation is the property of its rightful owner.
Sponsored Links
1 / 15

CSF: How certain can we be? PowerPoint PPT Presentation


  • 69 Views
  • Uploaded on
  • Presentation posted in: General

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:

Download Presentation

CSF: How certain can we be?

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


Csf how certain can we be

CSF: How certain can we be?

Meira Louis

PGY1


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


Csf how certain can we be

  • 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 antibiotics75-90%

All common etiologies-antimicrobial therapy prior to LP40-60%

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


On a reassuring note

On a reassuring note…

Ray et al, 2006


  • Login