Lumbar Puncture
Kalpesh Patel, MD
Dept. of Pediatric Emergency Medicine
December 6, 2006
2
Objectives
To learn the indications and contraindications for performing lumbar puncture
To learn lateral decubitus and sitting procedure for lumbar puncture
To learn the median and paramedian approach To review complications that can occur with lumbar
puncture, their precautions and treatments
3
History
CSF first examined in 19th century using primitive techniques (sharpened bird quills)
Modern technique first performed by Quincke in 1890 on a small child and has changed little since then
4
Indications
To obtain CSF for the diagnosis of:• Meningitis• Meningoencephalitis• Subarachnoid hemorrhage• Malignancy – diagnosis and treatment• Pseudotumor Cerebri• Other neurologic syndromes
5
Contraindications
Unstable patient with cardiovascular or respiratory instability
Localized skin/soft tissue infection over puncture site
Evidence of unstable bleeding disorder• Platelets < 50,000 or clotting factor deficiency
6
Contraindications
Increased intracranial pressure • Head CT before study if focal neurologic findings
present to rule out impending cerebral mass herniation
• Normal CT does not preclude intracranial HTN• Do not delay antibiotics to obtain imaging studies
when bacterial meningitis is strongly suspected Neurologic deterioration can occur if LP is done
below the level of a complete spinal subarachnoid block
Caution in patients with Chiari malformations
7
Equipment
Most CSF trays come with:• Anesthetic such as:
Topical - EMLA, Elamax, Zylocaine cream
Lidocaine 1% with 25 gauge needle and syringe
• Povidone-iodine solution & sponge wand• Drapes, gauze, and bandages• Manometer, stopcock and tubing in non-
infant kits
8
Equipment
Spinal needle, usually 22 gauge• 1.5 in for < 1 yr• 2.5 in for 1 year to
middle childhood• 3.5 in for older
children and adolescents
• Larger for large adolescents
Atraumatic needles, less spinal headaches
9
Lateral Decubitus Position
Apply topical anesthetic 30-45 min prior to procedure Spinal cord ends at L1-L2, so sites for puncture are
located at L3-L4 or L4-L5 Restrain patient in lateral decubitus position
• Maximally flex spine without compromising airway
• Keep alignment of feet, knees and hips
• Position head to left if right handed or vice versa
10
Procedure
Cleanse skin with povidone iodine from puncture site radially out to 10 cm and ALLOW TO DRY
Drape below patient and around site with fenestrated drape
Anesthetize with lidocaine if topical not used by:• Intradermally raising a wheal at needle insertion
site• Advance needle through wheal to desired
interspace Careful not to inject into a blood vessel or
spinal canal
11
Procedure
Insert spinal needle with stylet with bevel up to keep cutting edge parallel with nerve and ligament fibers
12
Procedure
Aim towards umbilicus directing needle slightly cephalad
Hold needle firmly
13
Procedure
A “pop” of sudden decrease in resistance indicates that ligamentum flavum and dura are punctured
Remove stylet and check for flow of spinal fluid
14
Procedure
If no fluid, then:• Rotate needle 90°• Reinsert stylet and advance needle slowly
checking frequently for CSF Jugular vein compression can increase CSF
pressure in low flow situations If bony resistance is felt immediately then you are
not in the spinal interspace If bony resistance is felt deeply, then withdraw
needle to the skin surface and redirect more cephalad and increase patient flexion
If bloody fluid that does not clear or that clots results, then withdraw needle and reattempt at a different interspace
15
Manometry
When CSF flows, attach manometer to obtain opening pressure if desired
Pressure can only be accurately measured in lateral decubitus position and in the relaxed patient
Attach manometer with a 3-way stopcock when free flow of CSF is obtained
Read column when highest level is achieved and respiratory variation is noted
16
Procedure
Collect 1ml of CSF in each of 3 vials for:• Tube 1: culture & gram stain• Tube 2: glucose, protein• Tube 3: cell count & differential• and extra CSF if desired for other lab tests
Check closing pressure with manometer, if desired Reinsert stylet and remove needle in one quick
motion Cleanse back and cover puncture site
LP The Movie
18
Sitting Position
Restrain infant in the seated position with maximal spinal flexion• Hold infant’s hands between
flexed legs with one hand and flex head with the other hand
Drape patient below buttocks and fenestrated drape opening over puncture site
Insert needle so bevel is parallel to spinal cord (Bevel left or right)
Cannot measure pressure accurately in this position
19
Paramedian (Lateral) Approach
Use for patients who have calcifications from repeated LPs or anatomic abnormalities
Needle passes through erector spinae muscles, and ligamentum flavum• Bypasses
supraspinal and interspinal ligaments
Less incidence of spinal headache
20
Complications
Headache • Uncommon in < 10 y/o
Apnea (central or obstructive) Back pain
• Occasionally with short-lived referred limp• Disc herniation if needle advanced too far
Bleeding or fluid leak around spinal cord Infection, pain, hematoma Subarachnoid epidermal cyst Ocular muscle palsy (transient) Nerve Trauma Brainstem herniation
21
Spinal Headache
Most common complication Risk factors: female, age 18-30, lower BMI, hx of
HA, prior spinal HA Bilateral HA, improves when supine Can last hours to weeks Supine position for at least 2 hours Hydration Caffeine either PO or IV Epidural blood patch
22
Spinal Headache Prevention
Can avoid by:• Passing needle bevel parallel to longitudinal
fibers of dura• Replacing stylet before removing needle• Using small diameter needles• Using atraumatic needles
Bed rest or PO intake after LP does not reduce incidence of headache
23
Nerve Root Trauma/Irritation
Can feel electric shocks or dysesthesias Back pain can persist for months
• Consider disc herniation Rarely permanent Withdraw needle immediately If pain or motor weakness persists, start
corticosteroids Electromyogram/nerve conduction velocity studies
should be scheduled if pain persists
24
Herniation
Manifests initially as altered mental status, followed by cranial nerve abnormalities and Cushing triad
May be rapidly fatal. Immediately remove needle and raise the head of
bed to 30-45° improve venous return from the brain. Mannitol or 3% Saline Intubate patient and hyperventilate Emergent neurosurgical consult
25
Epidermal Inclusion Cyst
Very rare due to use of stylet Occurs when a core of skin is driven into spinal or
paraspinal space with hollow needle Do not remove stylet until through the skin
26
Failure of Procedure
If sample of CSF is critical several alternatives are available:• Have someone else try
Anesthesia Neurology
• Bedside ultrasound for difficult LPs
• Radiographic guided procedure Fluoroscopy Ultrasound CT
• Cisterna Magna tap
27
Questions?
28
Bibliography
Fleisher GR, Ludwig S, Henretig FM. Textbook of Pediatric Emergency Medicine Fifth Edition. Lippincott Williams & Wilkins 2006. p201-212.
Levin DL, Morriss FC. Essentials of Pediatric Intensive Care Second Edition. Churchill Livingstone 1997. p369-370,411-412.
Robertson J, Shilkofski N. The Harriet Lane Handbook Seventeenth Edition. Elsevier Mosby. 2005. p86-88.
King C, Henretig Fred. Pediatric Emergency Procedures. Lippincott Williams & Wilkins 2000. p 124-128.
Straus SE, Thorpe KE, Holroyd-Leduc J. How do I perform a lumbar puncture and analyze the results to diagnose bacterial meningitis? JAMA. 2006 Oct 25;296(16):2012-22.
Peterson MA, Abele J. Bedside ultrasound for difficult lumbar puncture. J Emerg Med. 2005 Feb;28(2):197-200.
Runza M, Pietrabissa R, Mantero S. Lumbar Dura Mater Biomechanics: Experimental Characterization and Scanning Electron Microscopy Observations. Anesthesia and Analgesia. 1999;88:1317-21.
Sucholeiki R, Waldman A. Lumbar Puncture (CSF Examination). E-medicine. 2006 http://www.emedicine.com/neuro/topic557.htm.
Walter K. Manual of Common Bedside Surgical Procedures Second Edition. Lippincott Williams & Wilkins 2000. p181-186.
Boon JM, Abrahams, PH, Meiring JH, Welch T. Lumbar Puncture: Anatomical Review of a Clinical Skill. Clinical Anatomy 2004;17:544-553
Evans RW. Special Report: Complications of Lumbar Puncture and Their Prevention with Atraumatic Lumbar Puncture Needles. Medscape 2000. http://www.medscape.com/viewarticle/420288.