Cesarean delivery: a randomized trial of epidural versus patient-controlled meperidine analgesia during labor

Reports indicate that the administration of epidural analgesia for pain relief during labor interferes with labor and increases cesarean deliveries. However, only a few controlled trials have assessed the effect of epidural analgesia on the incidence of cesarean delivery. The authors' primary purpose in this randomized study was to evaluate the effects of epidural analgesia on the rate of cesarean deliveries by providing a suitable alternative: patient-controlled intravenous analgesia.

Seven hundred fifteen women of mixed parity in spontaneous labor at full term were randomly assigned to receive either epidural analgesia or patient-controlled intravenous meperidine analgesia. Epidural analgesia was maintained with a continuous epidural infusion of 0.125% bupivacaine with 2 microg/ml fentanyl. Patient-controlled analgesia was maintained with 10-15 mg meperidine given every 10 min as needed using a patient-controlled pump. Procedures recorded in a manual that prescribed the intrapartum management were followed for each woman randomized in the study.

A total of 358 women were randomized to receive epidural analgesia, and 243 (68%) of these women complied with the epidural analgesia protocol. Similarly, 357 women were randomized to receive patient-controlled intravenous meperidine analgesia, and 259 (73%) of these women complied with the patient-controlled intravenous analgesia protocol. Only five women who were randomized and received patient-controlled intravenous meperidine analgesia according to the protocol crossed over to epidural analgesia due to inadequate pain relief. There was no difference in the rate of cesarean deliveries between the two analgesia groups using intention-to-treat analysis based on the original randomization (epidural analgesia, 4% [95% CI: 1.9-6.2%] compared with patient-controlled intravenous analgesia, 5% [95% CI: 2.6-7.2%]). Similar results were observed for the analysis of the protocol-compliant groups (epidural analgesia, 5% [95% CI: 2.6-8.5%] compared with patient-controlled intravenous analgesia, 6% [95% CI: 3-8.9%]). Women who received epidural analgesia reported lower pain scores during labor and delivery compared with women who received patient-controlled intravenous analgesia.

Epidural analgesia was not associated with increased numbers of cesarean delivery when compared with a suitable alternative method of analgesia.