The Lumbar Puncture:The Lumbar Puncture:This (Really) Is Spinal TapThis (Really) Is Spinal Tap

OutlineIndications 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 QuinckeGerman 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/EncephalitisInflammatory polyneuropathies

MS, Guillan-Barre, etc.

Carcinomatous meningitis, tuberculous meningitisCSF disorder (hydrocephalus, NPH, pseudotumor cerebri)Therapeutic (i.e., intrathecal chemo, anesthesia)Injection for myelography

ContraindicationsIncreased ICP

Exam: Papilledema, focal neurologic examHistorical concerns: recent trauma/seizures

Focal infection at the LP site

Severe Coagulation defects

Abnormal Anatomy/Mass

Spinal Fracture

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 CTAge >60ImmunocomprimisedHistory of CNS disease/tumorNeurologic AbnormalitySeizureDepressed mental status

NPV 97%Other 3% did not have issues with LP

Indications for a head CTIncreased ICP

Altered MS, papilledema, focal neuro exam

History of recent head trauma or new seizures

ImmunosuppressionNeutropenia, HIV

Recurrent meningitis

Recent OM, sinusitis for possible parameningeal focus (relative)

Procedural techniqueGoal 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 routeSkin

Supraspinous and interspinous ligaments

Ligamentum flavum

Epidural space

Dura

Subarachnoid membrane and space

Procedural stepsH&P, consider need for pre-LP CT scan

ABX +/- steroids?

Informed consent

Gather your materialsLP kitCleaning solution (Betadine or Chlora-Prep)Extra LidocaineSterile GlovesExtra sterile tubes (if necessary)Chux padsExtra Needle (atraumatic or smaller gauge)

Consider procedural sedationDiazepam 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 stepsOpen 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 stepsWait 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 CSFSome remove stylet once in intraspinus ligaments

Troubleshooting

Needle angle

Bone spur?

Positioning?

Procedural stepsAttach 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 needleA strand of arachnoid may be drawn out with needle600 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 hoursNon-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 QuinckeObviously, 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 herniationIf you get neurologic changes, remove needle immediatelyReverse Trendelenburg, hyperventilate and call Neurosurgery!

Postspinal headacheMost common complication (10-15%)Use smallest gauge needle possibleTreat with analgesics/epidural blood patchCaffeine 500mg IV x1

Local bleeding/infection

Nerve trauma/pain

CSF studiesTube 1: cell count/diffTube 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 PCRVDRL, 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 FOR THE LOVE OF GOD, PLEASE HAND-CARRY ALL CSF TO THE LAB YOURSELF.THE LAB YOURSELF.

AccessioningIF IMPORTANT, DO IT YOURSELF!

In CHCS go to lab testsType Now, Ward/clinic collect, STATType 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 pressureNormal 6-18 cm H2O

Falsely elevated in sitting position or a tense patient

Fluid appearanceFluid 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 interpretationCell count

“Normal” is no more that 5 wbc’s and 1 neutrophilFor bloody taps: 700 rbc/ 1 wbcIf dump the CSF from the manometer, you should be ashamed!

Protein – normal 15/40 mg/dL1 mg increase for 1000 rbc’sVery elevated in infections, mildly elevated in inflammatory disease

Glucose – normal 45-80 mg/dLNormal is >0.6 of blood glucose level Ratio of <0.4 has positive LR of 13

CSF MicrobiologyIf important, look at it yourself!Gram stain

Always check with Microbiology regarding the gram stain results80% positive with bacterial pathogenGPR: think Listeria!

CulturesReview plates daily with Microbiology

Call Childrens for HSV, EBV results in 1-2 day

Meningitis: Clinical PresentationStudy 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 examinationKernig’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

MeningitisAseptic:

Amoebae, toxo, rickettsia, othersDrugs: NSAID’s, sulfa, IVIG, INHRheumatic diseases (SLE)CancerSarcoid

Organism depends on:AgeMedical Conditions/Immune StatusVaccine 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

TreatmentDroplet isolation for 24-48 hours.

Empiric antibiotics:Ceftriaxone 2 g IV q12hVancomycin 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 + vancomycinImmunocompromise – vancomycin/cefepime/ampicillinPCN allergy – vancomycin/TMP-SMX/+/- chloramphenicol

TreatmentAcyclovir in cases of HSV

+PCR in CSF in cases of meningitisEmpirically in cases of encephalitis 10 mg/kg IV q8h – maintain good UOP

Steroids Dexamethasone 10 mg IV q6hDose before antibiotics. Reduces TNF.

Increased ICP:ICU management, elevation of head to 30 degrees, mannitol, hyperventilation to pCO2 of 30mmHg, steroids.

Questions?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.