procedure
Last reviewed 01/2018
- put gloves on
- put a drape on top of the patient
- clean the area e.g. with betadine
- anaesthetise the skin and subcutaneous tissues with 1% lignocaine at the chosen site
- place the spinal needle in the interspace with the bevel uppermost and advance it towards the umbilicus keeping it parallel to the ground
- when advancing the needle consider:
- when there is an increase in resistance as you go into the tough ligamentum flavum and a marked reduction of resistance when the needle passes through. When through the ligamentum flavum, the dura is very close (1-2mm away) and the needle should be slowly advanced and the stylet withdrawn after each step
- when the dura is reached there should be a free flow of cerebrospinal fluid (CSF)
- measure the opening pressure with a manometer - if greater than 40 cm of water, remove needle immediately to avoid brain stem herniation. Normal pressure is 6-20 cm of water