Epidural Needles: Understanding Size, Length, And Design For Accurate Spinal Injections

Epidural needles are designed to access the epidural space, which is a narrow space surrounding the spinal cord. They typically range in size from 17 to 20 gauge (G), with larger numbers indicating smaller needle diameters. For example, an 18G needle has an outer diameter of approximately 1.2mm and an inner diameter of about 0.8mm. The length of epidural needles can vary from 3.8cm to 10.2cm, depending on the intended location of the epidural injection.