### Procedure ![[D698DE9F-1945-4804-88D9-454398FE45C5.png|400]]^[Blausen.com staff (2014). "Medical gallery of Blausen Medical 2014". WikiJournal of Medicine 1 (2). DOI:10.15347/wjm/2014.010. ISSN 2002-4436] 1. **Palpate the intercristal line** connecting the superior iliac crests, which typically identifies the L3 spinous process or L3-4 interspinal space^[Chakraverty R, Pynsent P, Isaacs K. Which spinal levels are identified by palpation of the iliac crests and the posterior superior iliac spines? _J Anat_. 2007;210(2):232-236. doi:[10.1111/j.1469-7580.2006.00686.x](https://doi.org/10.1111/j.1469-7580.2006.00686.x)]. Sterile prep the selected site. 2. **Insert needle with bevel up** at approximately 60° angle from coronal plane (along saggital plane, ie toward the umbilicus) through the interspinal space 3. Expect increased resistance when passing through ligament and dura, followed by **reduced resistance** often with a "pop" sensation 4. **Remove stylet** to check for CSF flow 5. If no flow or encountering bone, reinsert stylet, withdraw slightly, and redirect > **Important**: Keep needle bevel parallel to the longitudinal dural fibers (bevel facing up when patient is lateral decubitus) to minimize fiber disruption^[https://www.nysora.com/topics/complications/postdural-puncture-headache/], reduce CSF leakage, reduce post-dural puncture headache^[Norris MC, Leighton BL, DeSimone CA. Needle bevel direction and headache after inadvertent dural puncture. _Anesthesiology_. 1989;70(5):729-731. doi:[10.1097/00000542-198905000-00002](https://doi.org/10.1097/00000542-198905000-00002)], and avoid transection of blood vessels (bloody tap). ##### Additional Readings - Tool list and peds guide: https://www.rch.org.au/clinicalguide/guideline_index/Lumbar_puncture/ - Deeper exploration on postdural puncture headache: https://www.nysora.com/topics/complications/postdural-puncture-headache/ #procedure #Neurological