CHOOSING THE BEST NEEDLE FOR DIAGNOSTIC LUMBAR PUNCTURE

A new generation of Atraumatic (blunt tipped) needles now exists in ad dition to the traditional Quincke (cutting tip) needles for LP. We wis hed to identify the optimal size and type of needle that should be use d for this technique. Requirements include rapid and accurate transduc tion of CSF pressure and adequate flow rate for CSF collection purpose s while minimizing headache and other neurologic sequelae. Different t ypes of available Atraumatic and Quincke needles were tested in two mo dels that simulated normal and raised CSF pressures. The flow rates an d the time required for an accurate transduction of CSF pressure onto a standard spinal manometer through each needle type was measured. Ove rall, Atraumatic-tipped needles compared favorably with similarly size d Quincke needles tested. The 20-gauge needles displayed suitable flow and pressure transduction characteristics. Some of the 22-gauge Atrau matic needles rapidly measured CSF pressure, but their flow rates were only suitable for small volume CSF collection. There is extensive lit erature to support that neurologic sequelae are reduced using Atraumat ic needles. Diagnostic LP can be easily and accurately performed by us ing a large Atraumatic needle with the potential for considerable redu ction in post-LP headache and related neurologic sequelae.