Dilute Versus Concentrated Epidural Bupivacaine in Labor

Study Overview
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Brief Summary
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This study studies labor epidural analgesia and compares dilute (0.0625%) with concentrated (0.25%) bupivacaine. We hypothesize that patients randomize to receive the concentrated drug will require more drug, will have a more profound motor block, will be more likely to require instrumental delivery and will be less satisfied than those receiving dilute epidural drugs.

Detailed Description
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This study examines the effect of two different local anesthetic concentrations used for epidural analgesia in labor. Patients are randomized to receive epidural bupivacaine, either as a concentrated (0.25%), or a dilute (0.0625%) solution, both administered by patient-controlled epidural analgesia (PCEA).

Official Title
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Analgesia Requirement and Maternal Satisfaction Following Epidural PCA in Nulliparous Labor: the Effect of a Four-Fold Change in Local Anesthetic Concentration.

Conditions
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Pain, Labor Complications

Intervention / Treatment
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* Drug: Epidural bupivacaine (0.25% versus 0.0625%)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: nulliparity, active spontaneous labor, cervical dilatation greater than 2cm and less than 5 cm, request for epidural analgesia, age between 18 to 40, American Society of Anesthesiologists (ASA) physical status I or II, body weight less than 110kg, gestational age greater than 36 completed weeks, singelton pregnancy and vertex presentation Exclusion Criteria: narcotic administration in the previous 3 hours, non-reassuring fetal heart rate tracing at any stage in labor prior to enrollment, previous uterine surgery, pre-eclampsia and the inability to adequately understand the consent process.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Intervention/Treatment |
| --- |
|Drug: Epidural bupivacaine (0.25% versus 0.0625%)|nan|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 1. Anesthesia requirement: |  |  | 
| a. total dose (mg) of bupivacaine administered |  |  | 
| b. number of supplemental bolus doses of bupivacaine self-administered (by PCEA) |  |  | 
| c. total number of attempts for supplemental bupivacaine doses (including those denied) |  |  | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 1. Maternal satisfaction (visual analogue scale (VAS) with the anchors being 0 = maximally satisfied and 100 = maximally dissatisfied); after delivery and at 24 hours. |  |  | 
| 2. Speed of onset of analgesia. |  |  | 
| 3. Anesthesia variables (in labor q 1hr) |  |  | 
| a. Pain score VAS during uterine contraction |  |  | 
| b. sensory level |  |  | 
| c. motor power |  |  | 
| d. maternal blood pressure. |  |  | 
| 3.Obstetric outcome variables |  |  | 
| a. 1st stage duration |  |  | 
| b. 2nd stage duration |  |  | 
| c. Expulsive efforts |  |  | 
| d. Apgar scores at 1 and 5 min |  |  | 
| e. Instrumental delivery |  |  | 
| f. Cesarean section |  |  | 
| g. Non-reassuring fetal heart rate tracing in labor |  |  | 
| h. Occipito-posterior malrotation |  |  | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Labor Pain, Analgesia, Obstetrical, Pharmacology, Treatment Outcome