Pain Relief Effects on Length of Labor

A Randomized Single-blinded Trial of Combined Spinal-Epidural Versus Continuous Epidural Analgesia

This study divides patients into two groups when they ask for medicine to help relieve the pain of contractions. One group will be selected to receive an epidural and another group will be selected to receive both a spinal dose and an epidural. The investigators will then measure how long it takes to deliver the baby. The investigators think that the group that has the combination spinal and epidural will have a faster labor.

In this randomized controlled trial, the investigators will evaluate conventional continuous lumbar epidural analgesia compared to the combined spinal-epidural analgesia. The primary outcome of interest will be duration of the active phase of the first stage of labor. Secondary outcomes include the cesarean delivery rate, operative vaginal delivery rate, analgesia requirements, maternal and neonatal safety profiles (incidence of maternal hypotension, post puncture dural headache, fetal acidemia and NICU admissions, respectively), Adequacy of maternal pain relief will also be measured using visual analog scores (VAS). The investigators hypothesize that the instantaneous pain relief that is achieved with combined spinal-epidural analgesia reduces catecholamines quickly and to a greater degree than the conventional epidural, leading to a more effective uterine contraction pattern thus decreasing the duration of the active phase of the first stage of labor.

Inclusion Criteria:

• Nulliparous women
• Term gestation, defined as equal to or greater than 37 weeks
• Ages 16-44 years
• Singleton gestation
• Cephalic presentation
• Induction of labor on Monday 0700 through Friday 0700 at Parkland Hospital
• Intact membranes on admission

Exclusion Criteria:

• Chorioamnionitis at randomization
• Intrauterine fetal death
• Coagulopathy
• Allergies to amide local anesthetics
• Localized back infection