Procedural Steps
Patient Positioning
Site Preparation
Local Anesthesia
Needle Insertion
Collection of CSF
Removal of Needle
Post-procedural Care
Interpretation of Results
CSF Pressure

LP Pressure Quick Guide

It is best to have an assistant available to comfort the patient and help manage anesthetics and receive and label the test tubes of CSF obtained from the patient.

The necessary sterile equipment is often preassembled in an LP kit in the hospital setting.

Standard LP equipment

- Mask, gloves (& gown)
Prep solution
Small basin
4 X 4 gauze sponges
Sponge forceps
Sterile towels

- Local anesthetic
25 gauge 5/8" and 22 gauge 1.5" needles
Spinal needle
Four or five sterile test tubes with stoppers
(Manometer and 3-way stopcock)

A variety of LP needle types and sizes are available. A commonly used needle is a 22 gauge-3 inch LP cutting needle but some clinicians recommend a 25 gauge and this can be used in the child also.

The size and type of needle used for the LP is known to significantly affect the incidence of "post-LP headache" - postural headache - after a diagnostic LP. It occurs as much as in 50% of patients when a 20 gauge needle is used, and probably in 20- 30% after punctures with a narrower 22 gauge needle.

Atraumatic or non-cutting blunt LP needles will likely reduce the risk of post-LP headache significantly but are somewhat more difficult to use.

Information related to the choice of needle type can be found at the following Internet links:

  1. Atraumatic vs. Standard Needles for Diagnostic Lumbar Puncture. Thomas SR, et al. Randomised controlled trial of atraumatic versus standard needles for diagnostic lumbar puncture. BMJ October 2000;321:986-90

  2. Assessment: Prevention of post-lumbar puncture headaches
    Report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology. Randolph W. Evans, MD; Carmel Armon, MD, MHS; Elliot M. Frohman, MD, PhD; and Douglas S. Goodin, MD Neurology 2000;55:909-914

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