Lumbar Puncture

Lumbar Puncture

REQUIREMENTS:

Written Informed Consent, Gloves, Skin prep and Drape, Local anaesthesia kit, 20 or 22G styletted spinal needle, Collection tubes

PROCEDURE:

• Follow universal precautions and explain the procedure to the patient.

• POSITION: Given so as to increase the distance between two spinous processes.

• Antiseptic is applied at the puncture site from centre to outwards. 

• Local anaesthesia 2% lignocaine given (without epinephrine to avoid cord infarction). 

• A needle with stylet directed 10-15° cephalad, pointing towards patient's umbilicus (because spinous processes are directed downwards from the spine) 

Location: It is given in midline @ L3-L4 or L4-L5 level (horizontal line passing a between the 2 iliac crests passes through L4 spinous process)

 

• Keep the bevelled end up and in the midline.

• As soon as the dura is pierced a pop-up sensation or sudden loss of resistance is felt. 

• Withdraw stylet gradually. 

• CSF collection CSF comes out drop by drop. Collect it in 4 different sterile tubes for biochemical, microbiological, cytological and other tests respectively.

• After the procedure, insert the needle back in the cannula, withdraw the entire assembly. Apply a gauze, put a tight dynaplast. 

Ask the patient to be in supine position for 10-15 minutes. 

TIPS & TRICKS :

Before the antiseptic solution, there is a technique to mark the exact point of the LP. Identify the iliac crest, come medially→Mark/Indent the skin with the back of the needle cover→ then sterilize. 

After sterilizing, you can't palpate the iliac crest because that part is not sterile. 

So, either wear 2 pair of sterile gloves with sterile technique or wear 1 pair→do the sterilizing bit→then wear another pair. (don't touch the stylet with unsterile gloves) 

PROBLEMS FACED: 

1)

If the CSF still doesn't come, ask a  senior. Patient's BP may be low. If so,  give one pint normal saline, full flow after. Keep the needle at the same place (do not remove the needle), repeat the procedure after 10 minutes.

2)

If blood clots in the needle, use another needle. 

3) If patient complaints of sudden shooting pain in one leg (due to nerve injury by needle), move the needle medially. 

4) When you hit a bone, go down then sideways. While manipulating, especially while coming out, do it by slightly rotating the needle, and stopping briefly. Don't directly pull it. 

5) Guarded LP: when the CSF flow is very fast 

 

VIDEO LINK: https://youtu.be/CKLpIDhuJrE

 

Written by our guest author - Aakib Sohil Ghori
Illustrations by Anveshi Nayan
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