To compare the clinical efficacies and safety of intravenous nalbuphine and remifentanil combined with epidural block in labor analgesia.

A total of 150 full-term puerperae at Third Affiliated Hospital of Guangzhou Medical University from August to October 2020 were randomly divided into a simple epidural analgesia group (group C), a nalbuphine adjuvant epidural analgesia group (group N), and a remifentanil adjuvant epidural analgesia group (group R), with 50 cases in each group. All the three groups received epidural labor analgesia when their uterine orifices were opened to 3 cm. Within 10 minutes before the epidural puncture, group N was given intravenous injection of nalbuphine 0.1 mg/kg, and group R was given intravenous injection of remifentanil 0.20 μg/kg, then continuous intravenous infusion of remifentanil 0.05 μg/kg·min^-1 until the anesthesia level reached T10 and the infusion was stopped. All the three groups was given 0.065% ropivacaine + 0.4 μg/ml sufentanil epidural continuous infusion. The scores of Visual Analogue Scale (VAS) were recorded before analgesia, at epidural puncture, and each time point after analgesia. The duration of labor, the rate of cesarean section, the rate of instrumental-assisted labor, the utilization rate of oxytocin, and the maternal satisfaction were recorded. The neonates' Apgar scores (1, 5, and 10 min) were recorded, and their umbilical artery blood was extracted for blood gas analysis. The adverse reactions during delivery were observed. The independent-sample t, paired t, and χ² tests were applied.

The VAS scores at epidural puncture in group N and group R were significantly lower than that in group C [(5.68±1.13) and (5.61±1.11) vs. (8.10±1.00)], with statistical differences between group N and group C and between group R and group C (both P<0.05) but no between group N and group R (P>0.05). The scores of maternal satisfaction in group N and group R were higher than that in group C [(9.04±0.86) and (9.36±0.74) vs. (8.47±0.84)], with statistical differences between group N and group C and between group R and group C (both P<0.05) but no between group N and group R (P>0.05). The Ramsay sedation scores at epidural puncture in group N and group R was higher than that in group C [(1.75±0.43) and (2.17±0.60) vs. (1.17±0.38)], with statistical differences (both P<0.05). The incidences of dizziness in group N and group R were higher than that in group C [32% (16/50) and 40% (20/50) vs. 12% (6/50)], with statistical differences between group N and group C and between group R and group C (both P<0.05) but no between group N and group R (P>0.05). The incidence of narcolepsy in group R was 10% (5/50), which was statistically different from those in group N (0) and group C (0) (both P<0.05). There were no statistical differences in general data, VAS scores at other time points, improved Bromage scores at all the time points, time of labor, cesarean section rate, instrumental delivery rate, oxytocin utilization rate, Apgar score of newborns, and umbilical artery blood gas analysis between the three groups (all P>0.05).

Intravenous infusion of small doses of nalbuphine and remifentanil can significantly relieve the pain level before epidural labor analgesia takes effect and alleviate maternal tension, so that the puerperae can better cooperate with the anesthesiologists' instructions, create more favorable conditions for the anesthesia operation, improve their satisfaction, do not affect the delivery mode, do not prolong the labor process, and do not increase the occurrence of maternal and infant serious adverse reactions.

Nalbuphine; Remifentanil; Epidural block; Labor analgesia