Maintenance of epidural labor analgesia using programmed intermittent epidural bolus (PIEB) may be superior to continuous epidural infusion (CEI) analgesia in respects such as reducing the use of local anesthetic, improving the quality of analgesia, reducing motor block, and improving maternal satisfaction.1–4 In previous studies the incidence of breakthrough pain, defined as the woman complaining of pain or stress requiring supplemental treatment, was as high as 62.3%.5 Breakthrough pain may adversely affect the maternal labor experience.
