BANFF, ALTA. — Compared with systemic analgesia, the use of combined spinal epidural analgesia for external cephalic version is associated with a more rapid return of a reactive fetal heart rate tracing, according to findings presented by Dr. Jeanette Bauchat at the annual meeting of the Society for Obstetric Anesthesia and Perinatology.
“CSE [combined spinal epidural] may provide more immediate reassurance of fetal well-being following ECV [external cephalic version],” said Dr. Bauchat of Northwestern University, Chicago.
“Obviously we'd like to provide some pain control during this procedure but we want to ensure a safe analgesic technique,” Dr. Bauchat said.
In her study, 94 women undergoing ECV for breech presentation at 36 weeks' gestation were randomized to either CSE, consisting of intrathecal bupivacaine (2.5 mg) plus fentanyl (15 mcg), or systemic fentanyl (50 mcg intravenously). Fetal heart rate (FHR) tracings were evaluated for 30 minutes before the procedure and for 60 minutes afterward, for degree of variability, number of accelerations, number and type of decelerations and time to reactivity (TTR). TTR was defined as the time from initiation of analgesia to the development of two 15-beat accelerations of 15 seconds duration, occurring within 20 minutes of each other.
There were no differences noted between the groups for all aspects of fetal heart rate except TTR, which was significantly shorter in the CSE group (13 minutes compared with 39 minutes), reported Dr. Bauchat.
“Overall, 27% experienced some form of deceleration in both groups,” she said. “Post procedure, all the fetal heart rate tracings except for two ultimately returned to their baseline values. These two resulted in emergency cesarean deliveries—one in each group—for persistent nonreassuring decelerations.” A knot in the umbilical cord was identified in the CSE case, she added.