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.

A Randomized Trial of Dural Puncture Epidural Technique Compared with the Standard Epidural Technique for Labor Analgesia

“…16 The low incidence of PDPH after a 25 G Whitacre needle dural puncture would suggest that CSF flux is a time-limited phenomenon. 9 It is also possible that any additional contribution from flux through the dural hole during continuous epidural infusion is obscured by the analgesia produced via the epidural infusion. As the resting CSF pressure is typically higher than epidural space pressure, it is possible that a net efflux rather than influx limited further drug transfer from the epidural into the intrathecal space.…”

“…7 In contrast, in laboring parturients with a DPE technique using a 27-G Whitacre spinal needle, Thomas et al did not find any benefit compared with traditional epidural analgesia. 8 Acknowledging that the flux between the epidural and dural spaces is dependent on the size of the needle, 9 we hypothesized that the DPE technique with a larger 25-G Whitacre spinal needle would allow increased subarachnoid transfer of analgesic doses of epidurally administered drugs, and ultimately improve the onset, sacral spread, and overall quality of labor analgesia compared to a conventional epidural analgesia technique.…”

Managing anesthesia  for cesarean section in obese patients: current perspectives

“…The second issue relates to the ease of performing the neuraxial block. Most often, 25–27 gauge pencil point spinal needles are used in the obstetric population to decrease the risk of postdural puncture headache (PDPH) 67. The use of those small gauge needles might however be technically challenging in the morbidly obese parturients with excessive adipose tissue in the lumbar region, since the introducer used will be relatively short in this situation.…”

A comparison of three different gauge Quincke’s spinal needles in patients undergoing elective surgery under spinal anaesthesia: a prospective randomized study

“…Needle diameter, tip design and orifice location, have been altered to enable rapid flow of cerebral spinal fluid (CSF) and simultaneously limit dural trauma and loss of CSF. 1 A wide range of needles of different types and sizes are currently available for spinal anesthesia (SA). The needles are classified according to their gauge and shape.…”