Timing of Anesthesia During Labor Sparks Debate


SAN FRANCISCO — Data from recent studies call into question the recommendation that physicians delay administration of epidural anesthesia to nulliparous women in labor, Michael P. Nageotte, M.D., said at a meeting on antepartum and intrapartum management sponsored by the University of California, San Francisco.

The American College of Obstetricians and Gynecologists has recommended that “when feasible, obstetric practitioners should delay the administration of epidural anesthesia in nulliparous women until the cervical dilatation reaches 4–5 cm, and that other forms of analgesia be used until that time,” noted Dr. Nageotte, who is professor of obstetrics and gynecology at the University of California, Irvine.

Giving an epidural when the cervix is dilated less than 4 cm has been associated with a higher rate of cesarean delivery.

Investigators at Northwestern University, Chicago, led a recent study of 750 term nulliparous women who had experienced spontaneous labor or spontaneous rupture of the membranes. All of the women had a cervix that was dilated less than 4 cm on the initial exam and were told at the time of randomization that they would get an epidural if needed.

The women who participated were randomly assigned to receive either an intrathecal injection of fentanyl or systemic hydromorphone when they first requested analgesia. A woman's second request for analgesia resulted in administration of an epidural in the intrathecal group or assessment of cervical dilation in the systemic analgesia group. Women in the systemic group got an epidural if the cervix was dilated at least 4 cm, or received a second dose of systemic hydromorphone and were given an epidural upon their third request for analgesia.

The rate of cesarean delivery did not differ significantly between groups, but it was slightly higher in the delayed-epidural group, compared with the early-epidural group—21% vs. 18% (N. Engl. J. Med. 2005;352:655–65). The early-epidural group also had a significantly shorter time from receiving the first analgesia to complete cervical dilation (295 vs. 385 minutes) and a significantly shorter time from first analgesia to vaginal birth (398 vs. 479 minutes).

Women in the early-epidural group had better pain scores and were less likely to have babies with low Apgar scores at 1 minute. Rates of oxytocin use or intrapartum fever did not differ between groups.

In addition, Dr. Nageotte said he has reviewed two unpublished studies from Israel and from the United States that also suggest that delaying epidurals is not beneficial.

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