APARNA A1st year MSc Nursing

College Of NursingKottayam

LUMBAR PUNCTURE or SPINAL TAP is carried out by inserting a needle into Lumbar subarachnoid space to withdraw C S F

To obtain C S F for analysis & diagnosis of:◦ Meningitis

◦ Meningoencephalitis

◦ Subarachnoid hemorrhage

◦ Malignancy – diagnosis and treatment

◦ Pseudotumor Cerebri

◦ Other neurologic syndromes

To drain C S F & reduce intracranial space

To instill medications

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

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

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

Needle is inserted into subarachnoid space through intervertebral space

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

•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

•Sterile CSF tray with

•Spinal needle

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 oneside 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 •Describe the procedure step by

•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 cutting edge parallel with nerve and

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Needle is withdrawn & a small dressing is applied at puncture site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

Instruct patient to lie on prone for 2 to 3 hours

Monitor patient for any complications

Encourage increased fluid intake

Headache Back pain [Occasionally with short-lived ]◦ Disc herniation if needle advanced too far

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

Bed rest

Analgesics

Hydration

Epidural blood patch

Clear and colourless

Secreted by choroid plexus

Exists in subarachnoid space

It is about 150-200ml acts as shock absorber transports nutrients

1. If C S F is blood tinged 3 samples has to be collected

2. Uniformly stained SA H

3. CSF clears in 3rd bottle-Traumatic trap

1 2 3

1 2 3

Usually obtained for cell count, culture, glucose and protein testing

R B C and Differential W B C

Bacteriological –Gram stain and culture

Biochemical-Protein[0.15-0.45g/l]

- glucose [0.45-0.70g/l]

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