A randomized study of combined spinal-epidural analgesia versus intravenous meperidine during labor: impact on cesarean delivery rate.

BACKGROUND: Combined spinal-epidural (CSE) analgesia produces rapid-onset pain relief and allows ambulation in early labor. Epidural local anesthetics may contribute to an increase in operative deliveries by decreasing perineal sensation and causing motor weakness. Operative delivery rates might be reduced with CSE, by avoiding or delaying administration of local anesthetics. This study compares the operative delivery rates associated with a CSE technique and those associated with intravenous meperidine for labor analgesia.

METHODS: Healthy parturients at full term were assigned randomly to receive CSE or intravenous meperidine analgesia. The CSE group received 10 microg intrathecal sufentanil, followed by epidural bupivacaine and fentanyl at their next request for analgesia. Parturients receiving intravenous meperidine had 50 mg on demand (maximum, 200 mg in 4 h). Labor and delivery outcomes in both groups were recorded and compared.

RESULTS: An intent-to-treat analysis of 1,223 women indicated that CSE does not increase the rate of cesarean delivery for dystocia in nulliparous and parous women (CSE, 3.5% vs. intravenous meperidine, 4; P=not significant) or in nulliparous women alone (CSE, 7% vs. intravenous meperidine, 8%; P=not significant). Profound fetal bradycardia that necessitated emergency cesarean delivery within 1 h of the time the mother received sufentanil occurred in 8 of 400 parturients (compared with 0 of 352 who received meperidine; P < 0.01). However, the method of fetal monitoring differed between the two groups. Despite this, neonatal outcomes were similar overall.

CONCLUSIONS: Combined spinal-epidural analgesia during labor does not increase the cesarean delivery rate for dystocia in healthy parturient patients at full term, regardless of parity. However, an unexpected increase in the number of cesarean deliveries for profound fetal bradycardia after intrathecal sufentanil was observed. Further investigation is warranted.