Oxytocin at Elective Cesarean Deliveries: A Dose-finding Study in Women With BMI ≥ 40kg/m2
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 发起方
- 入组人数
- 30
- 试验地点
- 1
- 主要终点
- Uterine tone 2 minutes: questionnaire
研究概览
简要总结
Postpartum hemorrhage (PPH) due to uterine atony is a major cause of maternal morbidity and mortality. Uterotonic drugs are used to improve the muscle tone of the uterus after birth, and these are effective at reducing the incidence of PPH. Oxytocin is the most commonly used uterotonic drug to prevent and treat PPH. Large doses of this drug are asociated with adverse effects like low blood pressure, nausea, vomiting, abnormal heart rhythms and changes on ECG. Various international bodies recommend varying and high doses of oxytocin in elective cesarean sections. A study performed at Mount Sinai Hospital showed that a much smaller dose of oxytocin is required (ED95 being 0.35IU). However, most of the women included in this study were below a body mass index (BMI) of 40kg/m2.
The investigators seek to find the best dose for patients with a BMI>40kg/m2, as a higher dose may be needed in this population to contract the uterus adequately.
详细描述
Postpartum hemorrhage (PPH) is one of the leading causes of death during childbirth and accounts for an estimated 140,000 deaths per year worldwide. The World Health Organization (WHO) recommends active management of the third stage of labor to prevent PPH, even in low risk patients. Prophylactic uterotonic drugs administered after delivery are the main element of active management of the third stage and have been demonstrated to reduce the incidence of PPH by up to 40%. Oxytocin is the most commonly used uterotonic in North America, however it has a very short duration of action and requires a continuous infusion to achieve sustained effect, with large doses associated with adverse effects like low blood pressure, nausea, vomiting, abnormal heart rhythms and changes on ECG.
The prevalence of obesity is increasing in young women and some studies have shown that obese women have higher rates of caesarean delivery compared to non-obese women. Other studies have demonstrated an increased risk of hemorrhage due to poor uterine tone in obese women. Laboratory studies show that BMI alone appears to contribute to blunted uterine muscle responses and therefore contraction responses to oxytocin in obese women.
Previous dose finding studies have excluded those women with a BMI of ≥40kgm2. Therefore, the investigators wish to perform a double-blind dose finding study using the biased coin up-and-down sequential allocation technique to determine the ED90 of oxytocin at cesarean section in those women with a BMI>40.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Treatment
- 盲法
- Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
入排标准
- 年龄范围
- 18 Years 至 50 Years（Adult）
- 性别
- Female
- 接受健康志愿者
- 是
入选标准
- •BMI ≥40kg/m2
- •Elective cesarean delivery under regional anesthesia
- •Gestational age ≥ 37 weeks
- •No known additional risk factors for postpartum hemorrhage
- •Written informed consent to participate in this study
排除标准
- •Refusal to give written informed consent
- •Allergy or hypersensitivity to oxytocin
- •Conditions (other than high BMI) that may predispose to uterine atony and postpartum hemorrhage such as placenta previa, multiple gestation, severe preeclampsia (as defined by SOGC guidelines (21)), eclampsia, polyhydramnios, uterine fibroids, previous history of uterine atony resulting in PPH, or bleeding diathesis.
- •Hepatic, renal, and vascular disease
- •Use of general anesthesia prior to the administration of the study drug
研究组 & 干预措施
Oxytocin 0.5IU
Patient is given 0.5IU of oxytocin intravenously over 1 minute, immediately upon delivery of the fetal head.
干预措施: Oxytocin (Drug)
Oxytocin 1IU
Patient is given 1IU of oxytocin intravenously over 1 minute, immediately upon delivery of the fetal head.
干预措施: Oxytocin (Drug)
Oxytocin 2IU
Patient is given 2IU of oxytocin intravenously over 1 minute, immediately upon delivery of the fetal head.
干预措施: Oxytocin (Drug)
Oxytocin 3IU
Patient is given 3IU of oxytocin intravenously over 1 minute, immediately upon delivery of the fetal head.
干预措施: Oxytocin (Drug)
Oxytocin 4IU
Patient is given 4IU of oxytocin intravenously over 1 minute, immediately upon delivery of the fetal head.
干预措施: Oxytocin (Drug)
Oxytocin 5IU
Patient is given 5IU of oxytocin intravenously over 1 minute, immediately upon delivery of the fetal head.
干预措施: Oxytocin (Drug)
结局指标
主要结局
Uterine tone 2 minutes: questionnaire
时间窗: 2 minutes
Uterine tone, defined as satisfactory or unsatisfactory by the obstetrician at 2 minutes after completion of the oxytocin injection.
次要结局
- Intraoperative requirement for additional uterotonic medication(1 hour)
- Intravenous fluid administered during surgery(2 hours)
- Presence of ventricular tachycardia: ECG(2 hours)
- Need for uterine massage: questionnaire(20 minute)
- Presence of vomiting: questionnaire(2 hours)
- Calculated estimate of blood loss(24 hours)
- Bradycardia: heart rate less than 70% of baseline(2 hours)
- Presence of nausea: questionnaire(2 hours)
- Presence of headache: questionnaire(2 hours)
- Hypotension: systolic blood pressure less than 80% of baseline(2 hours)
- Tachycardia: heart rate greater than 130% of baseline(2 hours)
- Presence of atrial fibrillation: ECG(2 hours)
- Presence of atrial flutter: ECG(2 hours)
- Presence of shortness of breath: questionnaire(2 hours)
- Presence of flushing: questionnaire(2 hours)
- Presence of chest pain: questionnaire(2 hours)