APARNA A
1st year MSc Nursing
College Of Nursing
Kottayam
LUMBAR PUNCTURE or SPINAL TAP is carried
out by inserting a needle into Lumbar
subarachnoid space to withdraw C S F
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To obtain C S F for analysis & diagnosis of:
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Meningitis
Meningoencephalitis
Subarachnoid hemorrhage
Malignancy – diagnosis and treatment
Pseudotumor Cerebri
Other neurologic syndromes
To drain C S F & reduce intracranial space
To instill medications
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Increased intracranial pressure
◦ Head CT before study if focal neurologic findings
present to rule out impending cerebral mass
herniation
• If platelet count is less than 40,000 and
Prothrombin time is less than 50% of control
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Hydrocephalus- Enlarged ventricle size & in
suspected normal pressure Hydrocephalus
Coma- If C T is negative and I C P increased
Meningitis- Exclude mass lesion & confirm
diagnosis
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Use smallest possible gauge [20/22]
Prefer atraumatic rather than cutting needle
•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
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Needle is inserted into subarachnoid space
through intervertebral space
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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
•Sterile CSF tray
with
•Spinal needle
•Anesthetic such as:
Topical- Zylocaine cream or
Lidocaine 1% with 25 gauge needle
and syringe
•Povidone-iodine solution & sponge
•Drapes, gauze, and bandages
•Manometer, stopcock, tubing and
specimen bottles
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Obtain a written consent for the procedure
Explain the procedure to the patient
Determine whether patient have any doubts
or misconceptions
Reassure the patient
Instruct patient to void after procedure
•Position the patient at one
side of edge of bed
•Place a small pillow under
patient’s head & another
between the legs
•Assist the patient to maintain
position
•Encourage patient to relax & to
breath normally
•The physician cleanses the site
with antiseptic solution and drapes
the site
•Local anesthetic is injected to
numb the site and a spinal needle
is inserted to subarachnoid space
with stylet with bevel up to keep
A specimen of C S F is collected usually in
three test tubes
 Needle is withdrawn & a small dressing is
applied at puncture site
 Sent specimen to lab
immediately
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Instruct patient to lie on prone for 2 to 3
hours
Monitor patient for any complications
Encourage increased fluid intake
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Headache
Back pain [Occasionally with short-lived ]
◦ Disc herniation if needle advanced too far
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Bleeding or fluid leak around spinal cord
Infection, pain, hematoma
Subarachnoid epidermal cyst
Ocular muscle palsy (1%)
Nerve Trauma
Brainstem herniation
Throbbing bifrontal & occipital headache
 Dull and deep in character
 Severe on sitting or standing
IT CAN BE AVOIDED BY:
Using small gauge needle
Keep patient prone after procedure for 2 hours,
then side-lying for 2-3 hours, then supine or
prone for 6 or more hours
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Bed rest
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Analgesics
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Hydration
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Epidural blood patch
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Clear and colourless
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Secreted by choroid plexus
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Exists in subarachnoid space
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It is about 150-200ml acts as shock absorber
transports nutrients
1.
2.
If C S F is blood tinged 3 samples has to be
collected
Uniformly stained SA H
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3.
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3
CSF clears in 3rd bottle-Traumatic trap
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2
3
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Usually obtained for cell count, culture,
glucose and protein testing
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R B C and Differential W B C
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Bacteriological –Gram stain and culture
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Biochemical-Protein[0.15-0.45g/l]
- glucose [0.45-0.70g/l]
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SAH : Spectrophotometry
Malignant Tumor: Cytology
Tuberculosis: Polymerase chain reaction,
Jensen Culture
Non-bacterial Infection: Virology, fungal &
parasitic studies
Demyelinating Disease: Oligoclonal bands
Neurosyphilis: V D R L test
Cryptococcus: culture, antigen detection
H I V : culture, antigen detection & antiviral
antibodies