Effects of Bupivacaine Induced Motor Blockade During the Second Stage of Labor

Completed · Phase 4

Conditions studied: Pregnancy

In brief

The aim of this study is to measure the effects of bupivacaine administered via epidural catheters on indices of motor blockade ascertained during the second stage of labor. This is a randomized, double-blind, controlled trial designed to address the primary research question: Does bupivacaine lengthen the second stage of labor? The secondary research question is: Is there other evidence of motor blockade attributable to bupivacaine during the second stage of labor? The investigators know from prior studies that the length of the second stage in nulliparous women delivered at Parkland Hospital without epidural analgesia is 28 minutes. The investigators hypothesize in this now proposed study that epidural analgesia with bupivacaine will significantly increase this baseline from 28 minutes to 37 minutes or more (a 33% increase) thus implicating motor blockade. Baseline data for the Bromage and Breen scores during the second stage as well as the uterine contractility data are not available as these indices of motor blockade have not here-to-fore been studied in this context. Currently at Parkland Hospital, 82% of nulliparous women undergoing induction of labor at term receive continuous epidural infusions with bupivacaine during the first and second stages of labor. Such women will be identified when admitted for scheduled inductions at Parkland. After informed consent is obtained standard management of labor induction will be provided. Those consented women reaching 8 cm cervical dilation will be randomized. Group I will receive bupivacaine plus fentanyl via epidural catheter during the second stage (i.e. 10 cm dilation) and Group II will receive only fentanyl infusion via epidural catheter (see study procedure below). Both the patient and the caregiver will be blinded as to whether the patient is in the bupivacaine plus fentanyl arm or the fentanyl only arm. To detect a 33% increase (from 28 minutes to 37 minutes) in the primary outcome the investigators need a total of 310 women enrolled in the study (or 155 per arm). Assuming a 30% consent rate and given that approximately 1000 women meet the inclusion criteria each year at Parkland, the investigators project that this study could be completed in 12 months.

Key facts

Study ID

NCT01621230

Run by

University of Texas Southwestern Medical Center

People needed

481

Starts

2009-09-01

Expected to finish

2013-07-01

Last updated by the study team

2020-08-24

Who can join

Age: 16 and older, up to 44. Sex: female. Healthy volunteers: accepted.

You may qualify if…

• Nulliparous women at 37 weeks gestation or greater.
• Scheduled for induction of labor for any indication, to include hypertensive disorders, diabetes, decreased fetal motion, or prolonged pregnancy.
• Single without known malformations.
• Maternal age > or equal to 16 years.
• ASA classification 1 or 2.

You may not qualify if…

• Women who refuse epidural analgesia.
• Women with contraindications to epidural analgesia, i.e., severe thrombocytopenia.
• Any renal disease with serum creatinine > 1.0 mg/dL.
• Allergy to bupivacaine or fentanyl.
• Known liver disease such as hepatitis.
• Known contraindications to internal electronic fetal monitoring i.e., active herpes, maternal HIV seropositivity.

Where it is running

• Parkland Health and Hospital System — Dallas, Texas, United States

Full record on ClinicalTrials.gov

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