How To Do Lumbar Puncture By John E Greenlee, MD, University of Utah Health Reviewed / Revised May 2021 | Modified Sep 2022 View Patient Education Indications Contraindications Complications Equipment Additional Considerations Relevant Anatomy Positioning Step-by-Step Description of Procedure Aftercare Warnings and Common Errors Tricks and Tips Topic Resources Holding the Lumbar Puncture... Lumbar puncture Lumbar Puncture In lumbar puncture (LP), a needle is inserted into the lumbar subarachnoid space to collect cerebrospinal fluid (CSF) for laboratory testing, to measure CSF pressure, and sometimes to give intrathecal diagnostic or therapeutic agents.