Effects of Analgesic Techniques on Duration of Spontaneously Laboring Patients

Study Overview
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Brief Summary
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The purpose of this study is to determine if there is a difference in the duration of the first stage of labor in nulliparous women in spontaneous labor with whom analgesia is maintained with a combined spinal epidural (CSE) technique versus nulliparous women in spontaneous labor with whom an epidural de novo technique is utilized. The investigators hypothesize that the duration of the first stage of labor will be no different in nulliparous patients who receive either intrathecal fentanyl or intrathecal fentanyl and bupivacaine, as part of a CSE technique. However, the duration of the first stage of labor will be shorter in parturients who receive intrathecal analgesia (as part of a CSE technique) compared to those who receive an epidural de novo technique with fentanyl and bupivacaine.

Detailed Description
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At the first request for neuraxial labor analgesia, the cervix will be examined. If < 4.0 cm, the patient will be randomized to either Combined spinal epidural (CSE) technique with intrathecal fentanyl, CSE technique with intrathecal bupivacaine and fentanyl, or epidural de novo technique. Labor analgesia will be administered in the sitting position, at either the L2-3 or L3-4 interspace. All patients will receive a 500mL intravenous bolus of Lactated Ringer's solution. The epidural space will be located using the loss-of-resistance technique utilizing a 17-G Tuohy epidural needle. Patients assigned to an intrathecal dose will utilize the standard needle-through-needle technique. A 19-G epidural catheter will be inserted 5 cm in the epidural space and maintenance epidural analgesia will be initiated. Patients assigned to an epidural de novo technique will have the epidural space identified with a similar loss-of-resistance technique. The epidural catheter will be inserted 5 cm into the epidural space. Epidural analgesia will be initiated with fentanyl 100mcg + bupivacaine 0.125% 10-20 mL (in divided doses). Maintenance epidural analgesia will then be initiated. Maintenance epidural analgesia will consist of patient-controlled epidural analgesia (PCEA) with bupivacaine 0.0625% and fentanyl 1.95 mcg/mL at the following parameters: basal rate of 8 mL/hr with bolus dose = 8 mL, lock-out interval = 10 min and maximum volume = 32 mL/hr. Breakthrough pain in all groups will be managed using anesthesiologist administered epidural boluses of bupivacaine 1.25 mg/mL, 10-15mL, without fentanyl. If instrumental vaginal delivery is required, patients will receive anesthesiologist administered epidural boluses of chloroprocaine 30 mg/mL, 5-10 mL. If a patient does not have an adequate level of analgesia or has a one-sided block, despite epidural redoses, the epidural catheter will be replaced at another level and 0.125% bupivacaine 5-15 mL will be administered until an adequate level of analgesia is established. Because the primary outcome of the study is duration of first stage of labor, regular cervical examinations are necessary. Typically, full cervical dilation is diagnosed with a cervical examination only when the patient complains of rectal pressure, which is likely to be at a later time period in women with effective neuraxial analgesia compared to women with systemic opioid analgesia. Therefore, the duration of the first stage of labor will be artificially prolonged if regular cervical exams are not performed. The investigators intend to perform sterile cervical examinations at the first request for labor analgesia, then at routine times during the course of labor per the managing OB provider's discretion, and then every 2 hours after the patient reaches 90-100% cervical effacement until complete cervical dilation. Fetal heart rate (FHR) tracings without information about group assignment or other treatment modalities will be assessed by a perinatologist. In addition to analyzing FHR tracings for all included participants, the investigators also plan on analyzing plasma epinephrine levels which will be drawn in each subgroup of patients. Prior to placement of neuraxial technique, those patients included in this section of the study will have a sample of venous blood drawn. A second sample of venous blood will be redrawn 15 minutes and 30 minutes after the intrathecal dose or after initial epidural bolus. All three samples will then be analyzed for plasma epinephrine concentrations. These results will be compared with the FHR tracing analyses to see if there is any correlation.

Official Title
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A Randomized Trial of the Impact of Three Labor Analgesia Techniques on Labor Duration in Spontaneously Laboring Nulliparous Parturients

Conditions
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Effects of; Anesthesia, in Labor and Delivery, Pregnancy, Prolonged First Stage of Labor

Intervention / Treatment
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* Procedure: Epidural de novo
* Procedure: CSE


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Nulliparous, American Society of Anesthesia Physical Status (ASA) 2 females >18 years-old term (>37 weeks gestation) singleton vertex pregnancies spontaneous labor or spontaneous rupture of membranes Exclusion Criteria: Non-vertex presentation induction of labor contraindication to opioid or neuraxial analgesia contraindication to combine spinal-epidural technique (e.g. unfavorable airway exam) cervical dilation > 4.0 cm administration of systemic hydromorphone within 4 hours of epidural request

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Group E<br>Epidural de novo technique | Procedure: Epidural de novo<br>* Patients will have the epidural space identified with a loss-of-resistance technique utilizing a 17-G Tuohy epidural needle. The epidural catheter will be inserted 5 cm into the epidural space. Epidural analgesia will be initiated with fentanyl 100mcg + bupivacaine 0.125% 10-20 mL (in divided doses). Maintenance epidural analgesia will then be initiated.<br>|
| Active Comparator: Group BF<br>Combined spinal epidural (CSE) technique with intrathecal 0.5% Bupivicaine 2.5mg + Fentanyl 15mcg | Procedure: CSE<br>* The epidural space will be located using the loss-of-resistance technique utilizing a 17-G Tuohy epidural needle. Patients will receive the intrathecal study drug via a 27-G pencil-point spinal needle utilizing the standard needle-through-needle technique. A 19-G epidural catheter will be inserted 5 cm in the epidural space. Maintenance epidural analgesia will then be initiated.<br>|
| Active Comparator: Group F<br>Combined spinal epidural (CSE) technique with intrathecal fentanyl 25mcg | Procedure: CSE<br>* The epidural space will be located using the loss-of-resistance technique utilizing a 17-G Tuohy epidural needle. Patients will receive the intrathecal study drug via a 27-G pencil-point spinal needle utilizing the standard needle-through-needle technique. A 19-G epidural catheter will be inserted 5 cm in the epidural space. Maintenance epidural analgesia will then be initiated.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Duration of first stage of labor | Sterile cervical examinations at the first request for labor analgesia will be done, then at routine times during the course of labor per the managing OB provider's discretion. When the patient reaches 90-100% cervical effacement, cervical exams will be done every two hours thereafter until the patient reaches complete cervical dilation. Cervical examinations will be performed using a sterile glove, by each patient's labor and delivery nurse or physician. | Onset of contractions or spontaneous rupture of membrances to cervical dilation of 10cm | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Presence or absence of fetal heart rate decelerations |  | time of first analgesic dose - 60 minutes | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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pain, epidural, combined spinal epidural