To evaluate whether maintaining a motor-sparing epidural analgesia infusion affects the duration of the second stage of labor in nulliparous parturients compared with a placebo control.
We conducted a double-blind, randomized, placebo-controlled trial involving nulliparous women with term cephalic singleton pregnancies who requested epidural analgesia. All women received epidural analgesia for the first stage of labor using 0.08% ropivacaine with 0.4 micrograms/mL sufentanil with patient-controlled epidural analgesia. At the onset of the second stage of labor, women were randomized to receive a blinded infusion of the same solution or placebo saline infusion. The primary outcome was the duration of the second stage of labor. A sample size of 200 per group (400 total) was planned to identify at least a 15% difference in duration.
Between March 2015 and September 2015, 560 patients were screened and 400 patients (200 in each group) completed the study. Using an intention-to-treat analysis, the duration of the second stage was similar between groups (epidural 52±27 minutes compared with saline 51±25 minutes, P=.52). The spontaneous vaginal delivery rate was also similar (epidural 193 [96.5%] compared with saline 198 [99%], P=.17). Pain scores were similar between groups at each measurement during the second stage. More women who received placebo reported satisfaction scores of 8 or less (epidural 32 [16%] compared with saline 61 [30.5%], P=.001).
Maintaining the infusion of epidural medication had no effect on the duration of the second stage of labor compared with a placebo infusion. Maternal and neonatal outcomes were similar. A low concentration of epidural local anesthetic does not affect the duration of the second stage of labor.
Chinese Clinical Trial Register, http://www.chictr.org.cn/enindex.aspx, ChiCTR-IOR-15005875.
Departments of Anesthesiology and Obstetrics and Gynecology, Nanjing Maternity and Child Health Care Hospital, Nanjing Medical University, Nanjing, Jiangsu, China; and the Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts.
Corresponding author: Philip E. Hess, MD, YA-204B East Campus, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, MA 02215; email: firstname.lastname@example.org.
Financial Disclosure The authors did not report any potential conflicts of interest.
Presented at the Society for Obstetric Anesthesia and Perinatology, May 18–22, 2016, Boston, Massachusetts.
Each author has indicated that he or she has met the journal's requirements for authorship.