Carbetocin at Cesarean Delivery for Labor Arrest

Study Overview
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Brief Summary
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In 2009, the Society of Obstetricians and Gynecologists Canada, which produces national clinical guidelines on important women's health issues, recommended that a bolus of carbetocin 100 mcg into your vein should be used at elective cesarean delivery instead of oxytocin infusion for the prevention of bleeding after you deliver your baby. Similar to oxytocin, carbetocin has side effects that are dose-related. Although 100 mcg has been the recommend dose, studies in nonlaboring women suggest that doses lower than 100 mcg may be used to achieve the same degree of uterine contractility with less side effects. So far, the ideal dose to be used in cesarean sections for labouring women who have failure to progress in labour (failure of your cervix to dilate adequately to 10cm or the baby's head not descending the birth canal) has not been determined. This study is designed to determine the minimum carbetocin dose required during cesarean delivery for 'failure to progress' to achieve the best effect.

Detailed Description
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Post-partum hemorrhage (PPH) is a major cause of maternal death worldwide. Oxytocin is the most common uterotonic drug used to prevent and treat PPH in North America, however, there are some limitations to its use. Oxytocin has a very short duration of action, which requires a continuous infusion to achieve sustained uterotonic activity. The Society of Obstetricians and Gynecologists of Canada (SOGC) has recently recommended a single 100mcg dose of carbetocin at elective Cesarean delivery to promote uterine contraction and prevent post partum hemorrhage (PPH), in lieu of the more traditional oxytocin regimens. Carbetocin lasts 4 to 7 times longer than oxytocin, with a similar side effect profile and apparent greater efficacy rate. The evidence reported for Carbetocin use in the literature has mostly been based upon low risk non-laboring patients undergoing elective cesarean deliveries. At present, only 2 studies have looked at the use of Carbetocin in low risk patients requiring emergency cesarean deliveries. The minimum effective dose (ED90) of carbetocin in laboring women has not been determined so far. Similar to oxytocin, the ED90 of Carbetocin is likely to be higher in laboring women undergoing Cesarean deliveries as compared to the non-laboring women, due to the effect of the desensitization phenomenon. This study will be conducted as a prospective, randomized, up-down sequential allocation trial. The success or fail of a patient in the study will determine the dose given to future patients. Dosage will be increased for patients following a failed case, and kept the same for patients following successful cases. Following a successful case, there is also a 1 in 9 chance that the dose will be decreased for the next patient. The results of this study will establish the minimum effective dose of carbetocin for uterine contraction at cesarean delivery for labor arrest. This will likely minimize unnecessary side effects caused by a large bolus dose of the drug, and improve quality and safety of patient care.

Official Title
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Carbetocin at Cesarean Delivery for Labor Arrest: A Dose Finding Study

Conditions
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Postpartum Hemorrhage

Intervention / Treatment
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* Drug: Carbetocin


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: All patients who have given written informed consent to participate in this study. All patients planned for uncomplicated low transverse cesarean delivery secondary to labor arrest, under epidural anesthesia. ≥37 week pregnancy Singleton pregnancy Patients who have received oxytocin for at least 4 hours for labor augmentation ASA 1 or 2 Exclusion Criteria: Refusal or inability to obtain informed consent. All patients who claim allergy or hypersensitivity to oxytocin and carbetocin. Previous history of uterine atony or PPH Risk factors for PPH such as pre-eclampsia, polyhydramnios, uterine fibroids, bleeding diathesis and chorioamnionitis etc. Abnormal placental implantation (known or suspected) > 3 cesarean sections in the past Previous classic uterine incision Macrosomia - Estimated fetal weight > 4500g Hemoglobin < 100g/L Cesarean section under general anesthesia ASA 3 and 4 or patients with hepatic, renal, cardiac (eg. Coronary artery disease) and vascular disease Genital development problems (eg. Abnormal uterus, cervix, vagina, etc.) Uncontrolled hypotension or hypertension Uncontrolled diabetes Abnormal heart rhythms and bradycardia Drug abusers

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 55 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: Non-Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Carbetocin 10mcg<br>Carbetocin 10mcg IV, once following delivery. | Drug: Carbetocin<br>* Carbetocin IV, over 1 minute following delivery. Doses: 10, 20, 40, 60, 80, 100, 120 or 140mcg<br>* Other names: Duratocin;|
| Active Comparator: Carbetocin 20mcg<br>Carbetocin 20mcg IV, once following delivery. | Drug: Carbetocin<br>* Carbetocin IV, over 1 minute following delivery. Doses: 10, 20, 40, 60, 80, 100, 120 or 140mcg<br>* Other names: Duratocin;|
| Active Comparator: Carbetocin 40mcg<br>Carbetocin 40mcg IV, once following delivery. | Drug: Carbetocin<br>* Carbetocin IV, over 1 minute following delivery. Doses: 10, 20, 40, 60, 80, 100, 120 or 140mcg<br>* Other names: Duratocin;|
| Active Comparator: Carbetocin 60mcg<br>Carbetocin 60mcg IV, once following delivery. | Drug: Carbetocin<br>* Carbetocin IV, over 1 minute following delivery. Doses: 10, 20, 40, 60, 80, 100, 120 or 140mcg<br>* Other names: Duratocin;|
| Active Comparator: Carbetocin 80mcg<br>Carbetocin 80mcg IV, once following delivery. | Drug: Carbetocin<br>* Carbetocin IV, over 1 minute following delivery. Doses: 10, 20, 40, 60, 80, 100, 120 or 140mcg<br>* Other names: Duratocin;|
| Active Comparator: Carbetocin 100mcg<br>Carbetocin 100mcg IV, once following delivery. | Drug: Carbetocin<br>* Carbetocin IV, over 1 minute following delivery. Doses: 10, 20, 40, 60, 80, 100, 120 or 140mcg<br>* Other names: Duratocin;|
| Active Comparator: Carbetocin 120mcg<br>Carbetocin 120mcg IV, once following delivery. | Drug: Carbetocin<br>* Carbetocin IV, over 1 minute following delivery. Doses: 10, 20, 40, 60, 80, 100, 120 or 140mcg<br>* Other names: Duratocin;|
| Active Comparator: Carbetocin 140mcg<br>Carbetocin 140mcg IV, once following delivery. | Drug: Carbetocin<br>* Carbetocin IV, over 1 minute following delivery. Doses: 10, 20, 40, 60, 80, 100, 120 or 140mcg<br>* Other names: Duratocin;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| need for additional uterotonics | need for additional uterotonics in the OR at the time of cesarean section based upon the assessment of unsatisfactory/indeterminate uterine tone in response to the single bolus of carbetocin. | 30 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| uterine tone | Incidence of satisfactory, unsatisfactory and indeterminate uterine tone at every minute for five minutes and at 10 minutes following the completion of the injection of carbetocin. | 10 minutes | 
| uterine tone | Incidence of satisfactory, unsatisfactory/ indeterminate uterine tone as determined by the obstetrician/nurse after trans-abdominal palpation of the uterus in PACU within 2 hours of delivery of the placenta | 2 hours | 
| need for additional uterotonic | Need for delayed additional uterotonics within 24 hours after delivery outside the OR. | 24 hours | 
| Blood loss | Estimated blood loss will be calculated using blood results prior to the cesarean delivery and 24 hours post-delivery. | 24 hours | 
| side effects | Any of the following will be noted up to 2 hours post delivery: systolic blood pressure < 80% of pre-delivery values, tachycardia > 30% pre-delivery levels, bradycardia < 30% pre-delivery levels, other dysrhythmias, nausea, vomiting, chest pain, shortness of breath, headache, flushing, others | 2 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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pregnancy, postpartum hemorrhage, Cesarean delivery, carbetocin, failure to progress in labor