Needles used for spinal anesthesia.

Abstract

Since the discovery of spinal anesthesia in 1885 by J Leonard Corning, spinal needles have been modified to simplify their use and minimize complications. Needle design variables, such as diameter, tip design and orifice location, have been altered to enable rapid flow of cerebral spinal fluid (CSF) and injected medications, yet simultaneously limit dural trauma and loss of CSF. CSF loss can result in a severe postdural puncture headache (PDPH). Blunt pencil-point tip needles have been observed to cause a lower incidence of PDPH than similar sized sharp, cutting tip needles. Smaller diameter needles are also associated with a lower incidence of PDPH. A recent alteration in spinal needles is not to the needle per se, but rather the microcatheters placed through them; currently used in Europe, such catheters are again being evaluated in the USA. Further advancements in spinal needles will most likely involve some of the design elements previously altered, as well as new features not yet recognized as important at this time.