Cannulation of the Epidural Space A Comparison of 18− and 16-Gauge Needles

685 mothers scheduled to receive elective epidural analgesia in labor were randomly allocated to have the block administered via a 16− or 18− gauge Tuohy needle and catheter system. All blocks were performed by a midline approach utilizing a loss of resistance technique. The information elicited included the incidence of dural puncture by the needle or catheter, bleeding via needle or catheter, ease or difficulty of catheter passage, and patient discomfort during insertion.