Lumbar puncture: Difference between revisions

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==Correction for bloody tap==
== Correction for bloody tap ==
 
#Nl Ratio: 700 RBCs to 1 WBC
#Nl Ratio: 700 RBCs to 1 WBC
#Protein subtract 1mg/dL per 1000 RBCs
#Protein: subtract 1mg/dL per 1000 RBCs


==General Contraindications==
==Contraindications ==
# Infection at LP site
#Infection at LP site
# Severe thrombocytopenia (platelets <50) or bleeding diathesis or INR >1.5
#Severe thrombocytopenia (platelets <50) or bleeding diathesis or INR >1.5
# Mass lesion suspected (do CT or MRI first)
#Mass lesion suspected (do CT or MRI first)


==CT findings that prohibit LP==
== CT findings that prohibit LP ==
# Midline shift
#Midline shift
##Look for unequal pressures between the 3 cerebral compartments (left/right supretentorial compartments, posterior fossa)
##Look for unequal pressures between the 3 cerebral compartments (left/right supretentorial compartments, posterior fossa)
##Look for intracerebral masses not causing midline shift
##Look for intracerebral masses not causing midline shift
# Obsutrictive hydrocephalus
#Obsutrictive hydrocephalus
## Look for enlargement of ventricles prox to lesions and normal ventricles distal (especially 4th ventricle)
##Look for enlargement of ventricles prox to lesions and normal ventricles distal (especially 4th ventricle)
# Basilar cisterns compressed
#Basilar cisterns compressed
## Look for lateral/3rd ventricles may be small due to diffuse cerebral edema or enlarged due to obstr. hydroceph. +/- shift
##Look for lateral/3rd ventricles may be small due to diffuse cerebral edema or enlarged due to obstr. hydroceph. +/- shift
# Posterior fossa mass
#Posterior fossa mass
## Look for displacement/compression of 4th ventricle
##Look for displacement/compression of 4th ventricle
 
Consider contrast CT/MRI


(source: Emergency Radiology: Case Studies Schwartz)


==CT Head before LP==
==CT Head before LP==
In with meningitis suspected:
*If any of the following:
# AMS
#AMS
# Focal Neurologic deficit
#Focal Neurologic deficit
# Papilledema
#Papilledema
# Head Trauma or h/o CNS disease (recent or remote)
#Head Trauma or h/o CNS disease (recent or remote)
# New Onset Sz (<1 wk prior to ED visit)
#New Onset Sz (<1 wk prior to ED visit)
# HIV + / AIDS or any immunocompromised (transplant pt, steroids, cancer) patient
#HIV + / AIDS or any immunocompromised (transplant pt, steroids, cancer) patient
# Age > 60.
#Age > 60.
 
#VP shunt
-Hasbun, R. et al, (Yale), NEJM, Dec 13, 2001. (prospective, 301 pts)
 
===PEDIATRICS (Marianne)===
# VP shunt
# Febrile sx ?counts
 


NORMAL WBC
<br/>NORMAL WBC


Preterm: <25
Preterm: <25
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*May also order: cytology, VDRL, AFB stain/culture (often requires lab medicine approval), fungal stain (fungal cultures often require lab medicine approval), Cryptococcal antigen (CrAg), India Ink, oligoclonal bands, MBP, Lyme titers, HSV PCR.
*May also order: cytology, VDRL, AFB stain/culture (often requires lab medicine approval), fungal stain (fungal cultures often require lab medicine approval), Cryptococcal antigen (CrAg), India Ink, oligoclonal bands, MBP, Lyme titers, HSV PCR.


==Laboratory Results==
== Laboratory Results ==
===NORMAL===
 
=== NORMAL ===
 
Appearance Clear
Appearance Clear


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Pressure (cm H2O) 5-20
Pressure (cm H2O) 5-20


===Traumatic LP===
=== Traumatic LP ===
 
1000 RBC for 1mg/dL protein
1000 RBC for 1mg/dL protein


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Xanthrochromia tube 4; results from RBC lysis and hemoglobin breakdown.
Xanthrochromia tube 4; results from RBC lysis and hemoglobin breakdown.


===HEMORRHAGE===
=== HEMORRHAGE ===
 
Appearance Bloody or xantho
Appearance Bloody or xantho


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Pressure (cm H2O) Usually Inc
Pressure (cm H2O) Usually Inc


===BACTERIAL MENINGITIS===
=== BACTERIAL MENINGITIS ===
 
Appearance Cloudy or purulent
Appearance Cloudy or purulent


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Pressure (cm H2O) Usually Inc
Pressure (cm H2O) Usually Inc


===FUNGAL MENINGITIS===
=== FUNGAL MENINGITIS ===
 
Appearance Clear or cloudy
Appearance Clear or cloudy


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LA assay for crypto antigen 80%.
LA assay for crypto antigen 80%.


===ASEPTIC/VIRAL MENINGITIS===
=== ASEPTIC/VIRAL MENINGITIS ===
 
Appearance Clear
Appearance Clear


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Pressure (cm H2O) N or I
Pressure (cm H2O) N or I


===TB MENINGITIS===
=== TB MENINGITIS ===
 
Appearance Cloudy
Appearance Cloudy


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Pressure (cm H2O) Usually I
Pressure (cm H2O) Usually I


===HERPES ENCEPHALITIS===
=== HERPES ENCEPHALITIS ===
 
Appearance Bloody or xantho
Appearance Bloody or xantho


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Pressure (cm H2O) N or I
Pressure (cm H2O) N or I


===NEOPLASM===
=== NEOPLASM ===
 
Appearance Clear or xantho
Appearance Clear or xantho


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Pressure (cm H2O) Usually I
Pressure (cm H2O) Usually I


===GUILLAIN-BARR===
=== GUILLAIN-BARR ===
 
Appearance Clear or cloudy
Appearance Clear or cloudy


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Pressure (cm H2O) Normal
Pressure (cm H2O) Normal


===NEUROSYPHILIS===
=== NEUROSYPHILIS ===
 
Appearance Clear & cloudy
Appearance Clear & cloudy


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Pressure (cm H2O) N or I
Pressure (cm H2O) N or I


==Lumbar Puncture Note==
== Lumbar Puncture Note ==
 
#Consent
#Consent
#Indication
#Indication
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#Pt. tolerance
#Pt. tolerance


[[Category:Neuro]]
==Source==
[[Category:Procedures]]
Emergency Radiology: Case Studies Schwartz
Hasbun, R. et al, (Yale), NEJM, Dec 13, 2001. (prospective, 301 pts)
 
<br/>[[Category:Neuro]] <br/>[[Category:Procedures]] <br/> <br/><br/>

Revision as of 21:30, 30 June 2011

Correction for bloody tap

  1. Nl Ratio: 700 RBCs to 1 WBC
  2. Protein: subtract 1mg/dL per 1000 RBCs

Contraindications

  1. Infection at LP site
  2. Severe thrombocytopenia (platelets <50) or bleeding diathesis or INR >1.5
  3. Mass lesion suspected (do CT or MRI first)

CT findings that prohibit LP

  1. Midline shift
    1. Look for unequal pressures between the 3 cerebral compartments (left/right supretentorial compartments, posterior fossa)
    2. Look for intracerebral masses not causing midline shift
  2. Obsutrictive hydrocephalus
    1. Look for enlargement of ventricles prox to lesions and normal ventricles distal (especially 4th ventricle)
  3. Basilar cisterns compressed
    1. Look for lateral/3rd ventricles may be small due to diffuse cerebral edema or enlarged due to obstr. hydroceph. +/- shift
  4. Posterior fossa mass
    1. Look for displacement/compression of 4th ventricle


CT Head before LP

  • If any of the following:
  1. AMS
  2. Focal Neurologic deficit
  3. Papilledema
  4. Head Trauma or h/o CNS disease (recent or remote)
  5. New Onset Sz (<1 wk prior to ED visit)
  6. HIV + / AIDS or any immunocompromised (transplant pt, steroids, cancer) patient
  7. Age > 60.
  8. VP shunt


NORMAL WBC

Preterm: <25

Term: <22

Child: <7

  • May also order: cytology, VDRL, AFB stain/culture (often requires lab medicine approval), fungal stain (fungal cultures often require lab medicine approval), Cryptococcal antigen (CrAg), India Ink, oligoclonal bands, MBP, Lyme titers, HSV PCR.

Laboratory Results

NORMAL

Appearance Clear

Glucose (mg/dl) 50-75% serum

Protein (mg/dl) 15-45

Cell Count WBC 0-5

Differential 100% lymph, no PMN

Pressure (cm H2O) 5-20

Traumatic LP

1000 RBC for 1mg/dL protein

700 -1000 RBC gives 1 WBC

Xanthrochromia tube 4; results from RBC lysis and hemoglobin breakdown.

HEMORRHAGE

Appearance Bloody or xantho

Glucose (mg/dl) N or D

Protein (mg/dl) Inc but <1000

Cell Count RBC (<~50 okay)

(50-600 = gray zone)

(>600 c/w SAH)

Differential Same as blood

Pressure (cm H2O) Usually Inc

BACTERIAL MENINGITIS

Appearance Cloudy or purulent

Glucose (mg/dl) <40 or <40% serum

Protein (mg/dl) >100-500

Cell Count 100-100,000 (>5)

Differential >80% PMN

Pressure (cm H2O) Usually Inc

FUNGAL MENINGITIS

Appearance Clear or cloudy

Glucose (mg/dl) 20-40

Protein (mg/dl) 25-500

Cell Count 25-1000

Differential mono& lymph

Pressure (cm H2O) N or I

India ink 50% sensitivity

LA assay for crypto antigen 80%.

ASEPTIC/VIRAL MENINGITIS

Appearance Clear

Glucose (mg/dl) N or D

Protein (mg/dl) 50-200

Cell Count WBC 10-100

Differential Inc mono & PMN early, then lymph.

Pressure (cm H2O) N or I

TB MENINGITIS

Appearance Cloudy

Glucose (mg/dl) <40

Protein (mg/dl) 100-2000

Cell Count 50-500

Differential Most lymph, some PMN

Pressure (cm H2O) Usually I

HERPES ENCEPHALITIS

Appearance Bloody or xantho

Glucose (mg/dl) N or D

Protein (mg/dl) 50-100

Cell Count 20-500

Differential Mostly lymph

Pressure (cm H2O) N or I

NEOPLASM

Appearance Clear or xantho

Glucose (mg/dl) 40-80

Protein (mg/dl) 50-1000

Cell Count <100

Differential Mostly lymph

Pressure (cm H2O) Usually I

GUILLAIN-BARR

Appearance Clear or cloudy

Glucose (mg/dl) Normal

Protein (mg/dl) slight Inc

Cell Count <100

Differential Mostly lymph

Pressure (cm H2O) Normal

NEUROSYPHILIS

Appearance Clear & cloudy

Glucose (mg/dl) Normal

Protein (mg/dl) 40-200

Cell Count 200-500

Differential Mostly lymph & mono

Pressure (cm H2O) N or I

Lumbar Puncture Note

  1. Consent
  2. Indication
  3. Pressure
  4. Color
  5. Amount
  6. Tests
  7. Interspace
  8. Anesthesia
  9. Position
  10. Pt. tolerance

Source

Emergency Radiology: Case Studies Schwartz Hasbun, R. et al, (Yale), NEJM, Dec 13, 2001. (prospective, 301 pts)






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