Background: It has been reported that oxycodone is superior to the other opioids for the treatment of visceral pain. During the first stage of labor, pain is mainly caused by uterine contractions (visceral pain). It seems that oxycodone is more suitable for labor analgesia. During this study, we investigated the effects of adding oxycodone to ropivacaine on epidural analgesia during labor.
Materials and methods: Eighty nulliparous parturients were randomly divided into 2 groups. Group A received 0.2 mg/mL oxycodone plus 0.1% ropivacaine for epidural analgesia and group C (control group) received 0.1% ropivacaine alone for epidural analgesia. The onset time and duration of analgesia, duration of labor stages, delivery outcome, analgesic effect, Bromage scores, blood pressure, heart rate, and neonatal Apgar scores were recorded. Umbilical arterial blood was collected to analyze. Side effects, if any, were also recorded.
Results: The visual analog scale of pain was lower at 2 and 4 hours after analgesia and 10 cm cervical dilatation in group A compared with group C (P=0.021, 0.018, and 0.009, respectively). The onset time of analgesia was shorter in group A than that in group C (13.3±2.8 vs. 14.9±3.6 min, P=0.032). There were no significant differences between the 2 groups in terms of the duration of labor stages, delivery outcome, Bromage score, neonatal Apgar score, or umbilical arterial blood pH. The duration of analgesia was significantly longer in group A than in group C (326.2±56.5 vs. 68.4±10.5 min, P=0.000), but the incidence of pruritus was higher in group A than in group C (10% vs. 0%, P=0.115).
Conclusions: This study demonstrates that epidural oxycodone may accelerate the onset of analgesia and obviously prolong the duration of analgesia during labor without increasing adverse effects associated with the neonate. However, it may cause a higher incidence of maternal pruritus (registration number: ChiCTR1800016483).