1. health and fitness
2. disease

The Lumbar Puncture:
This (Really) Is Spinal Tap
Outline
Indications and contraindications
Use of CT scan
Procedural technique
Potential complications
Initial CSF studies and interpretation
Initial management of meningitis
History of LP
1891 by Heinrich Irenaeus Quincke
German Internist born in 1842
Died in Frankfurt in 1922
Designed to treat neonatal hydrocephalus
Now a famous rock band (Spinal Tap)
Quincke H. Ueber Hydrocephalus. Verhandl Cong Inn Med. 1891;10:321.
Indications
The time to do an LP is the time when you wonder, “should I
do an LP?”
Particularly if you’re considering encephalitis or meningitis.
SAH (if the CT is normal)
Meningitis/Encephalitis
Inflammatory polyneuropathies
MS, Guillan-Barre, etc.
Carcinomatous meningitis, tuberculous meningitis
CSF disorder (hydrocephalus, NPH, pseudotumor cerebri)
Therapeutic (i.e., intrathecal chemo, anesthesia)
Injection for myelography
Contraindications
Increased ICP
Exam: Papilledema, focal
neurologic exam
Historical concerns: recent
trauma/seizures
Focal infection at the LP site
Severe Coagulation defects
Spinal Fracture
Abnormal Anatomy/Mass
Spinal Hardware can be a
relative contraindication
Head CT
Never let a head CT delay the institution of
antibiotics (30 minute treatment time).
Head CT for subarachnoid, not meningitis
Study by Gopal in Arch Int Med 1999:
15% with CT had an abnormality, but only 2.7% with a lesion that
contraindicated LP
Three clinical Predictors pre-LP:
• Altered mental status
• Focal Exam
• Papilledema
301 Patients
Risks Factors for Mass Effect on CT
Age >60
Immunocomprimised
History of CNS disease/tumor
Neurologic Abnormality
Seizure
Depressed mental status
NPV 97%
Other 3% did not have issues with LP
Indications for a head CT
Increased ICP
Altered MS, papilledema, focal neuro exam
History of recent head trauma or new seizures
Immunosuppression
Neutropenia, HIV
Recurrent meningitis
Recent OM, sinusitis for possible parameningeal focus
(relative)
Procedural technique
Goal is to sample the CSF
from the subarachnoid
space at L3-L4 or L4-L5.
Nerve roots of the cauda
equina are at this level, but
they are simply pushed
over.
The spinal cord usually
ends at L1-L2.
Needle route
Skin
Supraspinous and
interspinous ligaments
Ligamentum flavum
Epidural space
Dura
Subarachnoid membrane
and space
Procedural steps
H&P, consider need for pre-LP CT scan
ABX +/- steroids?
Informed consent
Gather your materials
LP kit
Cleaning solution (Betadine or Chlora-Prep)
Extra Lidocaine
Sterile Gloves
Extra sterile tubes (if necessary)
Chux pads
Extra Needle (atraumatic or smaller gauge)
Consider procedural sedation
Diazepam 5mg, Lorazepam 1mg, Midazolam 1mg
Positioning, Positioning, Positioning
Lateral decubitus position or sitting
Fetal position to widen space
between the spinous processes
This is key
Palpate the iliac crests to locate
L4/L5, use thumbs to locate
Make an indentation with a pen
cap, or other device
Mark should not wash off
Procedural steps
Open the kit.
Pour betadine into tray, drop extra needles, etc
Put on sterile gloves.
Prepare the area in a circular fashion with betadine or
povidone-iodine.
Drape.
Inject 1-2% lidocaine at the site.
Needle Position
Bevel parallel or perpendicular to spine?
Parallel!
Bevel should be parallel to dural fibers
Less cutting and more separation
Reported 50% decrease in post-LP headache
Procedural steps
Wait 3-5 minutes for the anesthetic
effect
Introduce needle parallel to the bed,
bevel perpendicular to spine, in a 30-45
degree cephalad angle
Progress through the layers slowly
Feel the “pop” going into the
subarachoid space.
Don’t count on this…
Remove the stylet and look for CSF
Some remove stylet once in intraspinus
ligaments
Troubleshooting
Needle angle
Bone spur?
Positioning?
Procedural steps
Attach the manometer (instruct patient to relax) and check
the opening pressure
Collect four tubes of 2-5cc of CSF
Replace the stylet and remove the needle
A strand of arachnoid may be drawn out with needle
600 patient RCT (Strupp NEJM 1997) showed 3x reduction in
headache (16% vs. 5%, p<0.005)
Put a bandage at the site and remain supine for 2 hours
Non-significant benefit in several studies
Alternate Needles
Newer ‘atraumatic needles’
Sprotte needle designed in 80s
Now made by a company called
‘Pajunk”
Sprotte G, Schedel R, Pajunk H, et al.
An “atraumatic” universal
needle for single-shot regional
anesthesia: clinical results
and a 6 year trial in over 30,000
regional anesthesias. Reg
Anaesth 1987;10:104–108.
Atraumatic Meta-Analysis
Lenaerts used 20 G “Yale” instead of Quincke
Obviously, a poor study
Friends don’t let friends associate with Yale
Atraumatic Insertion
Atraumatic cannot penentrate
skin very well
Also is more flexible
Can use 18 gauge as guide
Atraumatic Spinal Needle
Potential complications
Brain herniation
If you get neurologic changes, remove needle immediately
Reverse Trendelenburg, hyperventilate and call
Neurosurgery!
Postspinal headache
Most common complication (10-15%)
Use smallest gauge needle possible
Treat with analgesics/epidural blood patch
Caffeine 500mg IV x1
Local bleeding/infection
Nerve trauma/pain
CSF studies
Tube 1: cell count/diff
Tube 2: protein, glucose, other chem (OCBs, MBP, etc.)
Tube 3: Gram stain, culture, other micro (HSV PCR, etc.)
Tube 4: cell count/diff, cytology
Special studies: Enteroviral, HSV PCR
VDRL, Cocci, Crypto, AFB, Fungal, etc.
Cytology (Presence of CNS malignancy)
Oligoclonal bands, myelin basic protein, etc.
Consider saving an ‘extra tube’ (especially for cytology)
FOR THE LOVE OF GOD, PLEASE HAND-CARRY
ALL CSF TO THE LAB YOURSELF.
Accessioning
IF IMPORTANT, DO IT YOURSELF!
In CHCS go to lab tests
Type Now, Ward/clinic collect, STAT
Type CSF
• Protein, Glucose, Cell count & Diff, Culture
Type Gram
• Sample name ‘CSF’
Other studies as necessary, may need MMO
• Miscellaneous Mail Outs, for Oligoclonal Bands
• Ordering these can be a pain in the @$$!!!
CSF interpretation
Opening pressure
Normal 6-18 cm H2O
Falsely elevated in sitting position or a tense patient
Fluid appearance
Fluid should appear clear
SAH: compare tubes 1 and 4; xanthochromia
• Xanthochromia should be determined by spectroscopy
• We don’t have a spectrometer… So you just look at it
CSF interpretation
Cell count
“Normal” is no more that 5 wbc’s and 1 neutrophil
For bloody taps: 700 rbc/ 1 wbc
If dump the CSF from the manometer, you should be ashamed!
Protein – normal 15/40 mg/dL
1 mg increase for 1000 rbc’s
Very elevated in infections, mildly elevated in inflammatory disease
Glucose – normal 45-80 mg/dL
Normal is >0.6 of blood glucose level
Ratio of <0.4 has positive LR of 13
CSF Microbiology
If important, look at it yourself!
Gram stain
Always check with Microbiology regarding the gram
stain results
80% positive with bacterial pathogen
GPR: think Listeria!
Cultures
Review plates daily with Microbiology
Call Childrens for HSV, EBV results in 1-2 day
Meningitis: Clinical Presentation
Study by Thomas, et al. CID, 2002
Headache - 92%
Fever - 71%
N/V - 70%
Photophobia - 57%
Stiff neck - 48%
Seizure - 9%
None were predictive (post-test odds .42-.57)
Examination: Meningitis
Exam:
Petechiae/rash
Genital lesions-usually not
present with HSV
Kernig’s: pain with knee
extension
Brudzinki’s: flexion of neck
leads to hip/knee flexion
Nuchal rigidity
Papilledema not consistent
with meningitis alone
Physical examination
Kernig’s:
Sens 5%, Spec 95%, PPV 27%, NPV 72%
Brudzinski’s:
Sens 5%, Spec 95%, PPV 27%, NPV 72%
Nuchal Rigidity:
Sens 30%, Spec 68%, PPV 26%, NPV 73%
Absence does NOT r/o disease!
Meningitis
Bacterial:
Strep pneumoniae, N. meningitidis, H. flu, Listeria,
GNR’s.
Aseptic:
Viral: enterovirus, HSV, arbovirus, HIV, WNV.
Bacterial: partially treated bacterial, TB
Spirochetes: Lyme, syphilis
Fungi: Cocci, Cryptococcus, Histo
Meningitis
Aseptic:
Amoebae, toxo, rickettsia, others
Drugs: NSAID’s, sulfa, IVIG, INH
Rheumatic diseases (SLE)
Cancer
Sarcoid
Organism depends on:
Age
Medical Conditions/Immune Status
Vaccine History
Bacterial meningitis
Neonates: GBS, E. coli/GNRs, Listeria
1-3 Mos.:
GBS, Listeria, S. pneumo, H. influenzae
3mo-9 yr.: S. pneumoniae, N. meningitidis
9-50 yr.:
S. pneumoniae, N. meningitidis
>50 yr.:
S. pneumoniae, N. meningitidis, Listeria,
GNR’s
Treatment
Droplet isolation for 24-48 hours.
Empiric antibiotics:
Ceftriaxone 2 g IV q12h
Vancomycin 15 mg/kg IV q12h (generally 1-1.5 g IV q12h)
Add ampicillin 2 g IV q4h for coverage of Listeria monocytogenes
if patient is >50 years old, immunosuppressed, pregnant, or
alcoholic.
Special situations:
Trauma/shunt – cefepime + vancomycin
Immunocompromise – vancomycin/cefepime/ampicillin
PCN allergy – vancomycin/TMP-SMX/+/- chloramphenicol
Treatment
Acyclovir in cases of HSV
+PCR in CSF in cases of meningitis
Empirically in cases of encephalitis
10 mg/kg IV q8h – maintain good UOP
Steroids
Dexamethasone 10 mg IV q6h
Dose before antibiotics. Reduces TNF.
Increased ICP:
ICU management, elevation of head to 30 degrees, mannitol,
hyperventilation to pCO2 of 30mmHg, steroids.
Questions?
References
• Practice parameters: Lumbar Puncture. Neurology, 1993;
43:625
• Special Techniques for neurologic diagnosis in Principles of
Neurology, 5th, 1993. New York: McGraw-Hill, p 11-16
• Cooper JR: Routine use of CT prior to lumbar puncture. Br J
Rad, 1999; 72:319
• Gopal AK, et al:Cranial CT before lumbar puncture. Arch
Intern Med, 1999; 159:2681.
• Waldman W and Laureno R: Precautions for lumbar puncture:
a survey of neurologic educations. Neurology, 1999; 52:1296.
References
• Converse GM, et al: Alteration of CSF findings by partial
treatment of bacterial meningitis. J Pediatr, 1973; 83: 220.
• Negrini B, et al: Cerebrospinal fluid findings in aseptic versus
bacterial meningitis. Pediatr, 2000; 105:316
• Tunkel AR and Scheld WM: Acute bacterial meningitis.
Lancet, 1995; 346:1675.
• Greenlee JE: Approach to diagnosis of meningitis:
Cerebrospinal fluid evaluation. Infect Dis Clin NA, 1990;
4:583.
• Quagliarello VJ and Scheld WM: Treatment of bacterial
meningitis. NEJM, 1997; 336:708.
References
• Flaatten H, et al:Puncture technique and postural postdural
puncture headache. A randomized double-blind study
comparing transverse and parallel puncture. Acta Anaesth
Scand, 1998; 42:1209.
• Sharma A: Preventing headache after lumbar puncture. BMJ,
1998; 317:1588.
• Nel MR: Epidural blood patching can be used to treat
headache. BMJ, 1998; 316: 1019.
• Kaplan SL: Clinical presentations, diagnosis, and prognostic
factors of bacterial meningitis. Infect Dis Clin NA, 1999;
13:579.