Efficacy of Remifentanil Intravenous Patient-Controlled Analgesia in Singleton Parturients During the Second Stage of Labor: A Single-Arm, Prospective Study

Worrying about increasing the use of instrument-assisted delivery and prolonging the process, midwives in our institution tended to persuade the parturients who had entered the second stage of labor, to give up neuraxial analgesia. Remifentanil seemed to be suitable for this situation due to its advantages of fast onset and metabolism. We designed a single arm and prospective study to explore the analgesic effect and safety of remifentanil intravenous patient-controlled analgesia (PCA) in singleton parturients during the second stage of labor.

Ten pregnancies were included, whose cervical dilation had exceeded 8 cm when they arrived into the delivery room. The patient was given 40 μg remifentanil intravenously as soon as she felt the contraction with a lockout time of 2 minutes. The maternal heart rate (MHR), mean arterial pressure (MAP), SpO2, fetal heart rate (FHR), OAA/S score, and VAS analgesia score were recorded before and at 5, 10, 20, 30, and 60 minutes after administration. An umbilical artery blood gas analysis and Apgar scores at 1 and 5 minutes were also recorded after the delivery of the newborn. The incidence of adverse events and overall satisfaction with analgesia were recorded.

The VAS score decreased from 9.2 to 4.6 after remifentanil administration. All umbilical artery PH values were beyond 7.20. All 1-minute newborns' Apgar scores were 8 points or greater, and 9 points or greater in the 5th minute. Adverse events included 3 cases of dizziness, 3 cases of nausea, 1 case of vomiting, and 1 case of parturients had a transient FHR drop at the 10th minute, accompanied by hypoxemia and hypersomnia. The overall satisfaction rate was 70%.

Remifentanil PCA could effectively relieve the severe uterine contraction pain suffered by the parturients in the second stage of labor with safety.