The Lumbar Puncture
A lumbar punctures is a procedure in which a needle is used to access the subarachnoid space. This may be used to collect cerebrospinal fluid (CSF) for diagnostic purposes, or therapeutic purposes in order to deliver drugs.
***
Explain the procedure and ask for patient's consent
It is important to continually communicate with the patient and tell them what you are doing
Position the patient
Sitting or lateral foetal position
Identify the L4/L5 Intervertebral Space
In the midline between iliac crests
Mark the Desired Site
L3/L4, L4/L5, L5/S1
Using the marking pen
Prepare Sterile Field
Don goggles and mask
Scrub, sterile glove and gown
Prepare Sterile Equipment
Place everything in the order it will be used
Prepare the Area
Decontaminate with chlorhexidine or povidone-iodine
Apply the fenestrated drape
Reposition the Patient
To ensure maximum flexion of the lumbar spine
Identify the Site Again
Maintaining sterile conditions
Inject Local Anaesthetic
Make a small wheal over the insertion site
Insert the Needle into the Midline
Slowly, with bevel up and facing slightly superiorly
A ‘pop' may be felt on entry to the dura
Remove the Stylet
Look for CSF drainage
If required - replace the stylet, remove the needle slightly and readvance at a different angle
Measure Opening Pressure
Attach the three-way tap and manometer
Collect CSF
Drain three 2mL samples into specimen containers
Reinsert the stylet
Remove the Needle
Look for CSF leakage
Apply the Dressing
Clean Up
Dispose of sharps and other waste
Remove gloves and wash hands
Processing
Label the collection tubes and send to the lab
Bed Rest
Check local guidelines for bed rest post LP
Inadequate Sample
Blood-stained, insufficient volume
Headache
May occur hours or days post LP
Back Pain
Bleeding
Around site or into the subarachnoid space
Cerebral Herniation
Don't perform LP if raised intracranial pressure
Infection
Meningitis, abscess