Up-Down Oxytocin Infusion

Study Overview
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Brief Summary
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This study is designed to determine the minimum effective dose (ED90) of infusions of oxytocin for the prevention of uterine atony / postpartum hemorrhage and the need for additional uterotonics, in low risk parturients presenting for an elective CD. The primary outcome measure is the response of effective uterine contraction as either satisfactory or unsatisfactory as determined by the obstetrician blinded to the oxytocin infusion dose. Secondary outcomes will include need for additional uterotonics, calculated intra-operative blood loss and presence of oxytocin related adverse effects.

Official Title
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Up-down Determination of the ED90 of Oxytocin Infusions for the Prevention of Postpartum Uterine Atony in Parturients Undergoing Cesarean Delivery

Conditions
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Uterine Atony

Intervention / Treatment
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* Drug: Oxytocin infusion


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Non-emergent cesarean delivery with planned spinal anesthesia (i.e. elective planned cesarean delivery for malposition, patient choice, cervical pelvic disproportion, previous cesarean delivery and other diagnosis that require a predetermined cesarean delivery) American Society of Anesthesia physical status class I & II (ASA I - Healthy, ASA II - mild and controlled systemic disease, eg. controlled essential hypertension) Age ≥ 18 years Term gestational age (≥ 37 weeks) English-speaking Exclusion Criteria: Morbid Obesity (Body Mass Index ≥ 45 kg/m2) (Morbidly obese parturients require a dose of local anesthetic less than the standardized dose in this study and the blood pressure cuff occasionally needs to be replaced by an intraarterial catheter due to limitations in size) Laboring women Urgent or emergency cesarean delivery Severe hypertensive disease of pregnancy defined as systolic blood pressure (SBP) > 160mmHg, diastolic blood pressure (DBP) > 110mmHg and/or requiring antihypertensive treatment or associated with significant proteinuria Severe maternal cardiac disease Subjects predisposed to uterine atony and postpartum hemorrhage (i.e. placenta previa, multiple gestation, macrosomia, polyhydramnios, uterine abnormalities, or bleeding diathesis, > 2 previous CD) Fetal anomalies /Intrauterine Fetal Demise Failed spinal anesthesia Patient enrollment in another study involving a study medication within 30 days of CD Any other physical or psychiatric condition which may impair their ability to cooperate with study data collection

Ages Eligible for Study
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Minimum Age: 18 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

Primary Purpose: Prevention
Intervention Model: Single Group Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: A<br> | Drug: Oxytocin infusion<br>* Up-down dosing determination<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The primary outcome measure is the response of effective uterine contraction as either satisfactory or unsatisfactory as determined by the obstetrician blinded to the oxytocin infusion dose. |  | 3 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Secondary outcomes will include need for additional uterotonics, calculated intra-operative blood loss and presence of oxytocin related adverse effects. |  | 2 days |