Norepinephrine To Prevent Hypotension After Spinal Anesthesia For Cesarean Delivery: A Dose Finding Study
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 发起方
- 入组人数
- 40
- 试验地点
- 1
- 主要终点
- Systolic blood pressure
研究概览
简要总结
Spinal anesthesia is the most common anesthetic technique for elective Cesarean delivery (CD), but the most frequent unwanted side effect is hypotension, which can cause nausea and vomiting, as well as effects on the fetus. Prevention and treatment of maternal hypotension includes intravenous fluids and vasopressors. Phenylephrine is the most common vasopressor used for this purpose. However, it has been shown to reduce maternal heart rate and cardiac output, which may be a concern in an already compromised fetus. Norepinephrine is commonly used in high concentrations in intensive care and recent studies have suggested that in low concentrations it may be a better alternative to phenylephrine in elective CD, as it does not reduce the maternal heart rate or cardiac output. The optimum bolus dose of norepinephrine to prevent hypotension after spinal anesthesia in elective CD has not been elucidated. The investigators propose this study to determine the dose that would be effective in 90% of patients (ED90).
A previous study by Ngan Kee et al, using continuous infusion of norepinephrine to prevent hypotension in elective CD, suggested a potency ratio for norepinephrine to phenylephrine of approximately 16:1. Hence, the investigators hypothesise that the ED90 will be approximately 6 µg, given that the current phenylephrine bolus dose at the investigators' institution is approximately 100 µg.
详细描述
The use of norepinephrine to prevent and treat hypotension during cesarean delivery (CD) is new and data in the literature are scarce. A recent randomised controlled trial by Ngan Kee et al compared continuous infusions of norepinephrine and phenylephrine to prevent hypotension during CD. They showed that norepinephrine was effective at maintaining blood pressure, with a greater cardiac output and heart rate compared to phenylephrine. However, the effective bolus dose of norepinephrine needed to prevent maternal hypotension was not determined, and since this is a relatively new arena, no dose-response studies are available in the literature either. Therefore, it would be logical to establish the effective bolus dose of norepinephrine TO PREVENT HYPOTENSION during elective CD.
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
- Triple (Participant, Care Provider, Investigator)
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
- •Elective CD under spinal anesthesia
- •Normal singleton pregnancy beyond 36 weeks gestation
- •ASA physical status II/III
- •Weight 50-100 kg, height 150-180 cm
- •Age over 18 years
- •Informed consent
排除标准
- •Patient refusal
- •Allergy or hypersensitivity to norepinephrine or sulfite
- •Preexisting or pregnancy-induced hypertension
- •Cardiovascular or cerebrovascular disease
- •Fetal abnormalities
- •History of diabetes, excluding gestational diabetes
- •Use of monoamine oxidase inhibitors, triptyline or imipramine antidepressants
研究组 & 干预措施
Norepinephrine 3 micrograms/mL
1mL of a solution of norepinephrine, containing 3 micrograms/mL in normal saline, will be given intravenously to a patient if her blood pressure decreases from baseline.
干预措施: Norepinephrine (Drug)
Norepinephrine 3 micrograms/mL
1mL of a solution of norepinephrine, containing 3 micrograms/mL in normal saline, will be given intravenously to a patient if her blood pressure decreases from baseline.
干预措施: Normal Saline (Drug)
Norepinephrine 4 micrograms/mL
1mL of a solution of norepinephrine, containing 4 micrograms/mL in normal saline, will be given intravenously to a patient if her blood pressure decreases from baseline.
干预措施: Norepinephrine (Drug)
Norepinephrine 4 micrograms/mL
1mL of a solution of norepinephrine, containing 4 micrograms/mL in normal saline, will be given intravenously to a patient if her blood pressure decreases from baseline.
干预措施: Normal Saline (Drug)
Norepinephrine 5 micrograms/mL
1mL of a solution of norepinephrine, containing 5 micrograms/mL in normal saline, will be given intravenously to a patient if her blood pressure decreases from baseline.
干预措施: Norepinephrine (Drug)
Norepinephrine 5 micrograms/mL
1mL of a solution of norepinephrine, containing 5 micrograms/mL in normal saline, will be given intravenously to a patient if her blood pressure decreases from baseline.
干预措施: Normal Saline (Drug)
Norepinephrine 6 micrograms/mL
1mL of a solution of norepinephrine, containing 6 micrograms/mL in normal saline, will be given intravenously to a patient if her blood pressure decreases from baseline.
干预措施: Norepinephrine (Drug)
Norepinephrine 6 micrograms/mL
1mL of a solution of norepinephrine, containing 6 micrograms/mL in normal saline, will be given intravenously to a patient if her blood pressure decreases from baseline.
干预措施: Normal Saline (Drug)
Norepinephrine 7 micrograms/mL
1mL of a solution of norepinephrine, containing 7 micrograms/mL in normal saline, will be given intravenously to a patient if her blood pressure decreases from baseline.
干预措施: Norepinephrine (Drug)
Norepinephrine 7 micrograms/mL
1mL of a solution of norepinephrine, containing 7 micrograms/mL in normal saline, will be given intravenously to a patient if her blood pressure decreases from baseline.
干预措施: Normal Saline (Drug)
Norepinephrine 8 micrograms/mL
1mL of a solution of norepinephrine, containing 8 micrograms/mL in normal saline, will be given intravenously to a patient if her blood pressure decreases from baseline.
干预措施: Norepinephrine (Drug)
Norepinephrine 8 micrograms/mL
1mL of a solution of norepinephrine, containing 8 micrograms/mL in normal saline, will be given intravenously to a patient if her blood pressure decreases from baseline.
干预措施: Normal Saline (Drug)
结局指标
主要结局
Systolic blood pressure
时间窗: 30 minutes
The primary outcome of this study will be the success/response of the norepinephrine dose to maintain the systolic blood pressure at or above 80% of baseline, from induction of spinal anesthesia to delivery of the fetus.
次要结局
- Umbilical artery bicarbonate(24 hours)
- Umbilical vein base excess(24 hours)
- Hypertension: Systolic blood pressure at or above 120% of baseline(30 minutes)
- Bradycardia: Heart rate less than 50 bpm(30 minutes)
- Presence of Vomiting(30 minutes)
- Umbilical artery pH(24 hours)
- Umbilical vein partial pressure of carbon dioxide(24 hours)
- Umbilical vein bicarbonate(24 hours)
- Presence of Nausea(30 minutes)
- Upper sensory level of anesthetic block, assessed by pinprick upon delivery(30 minutes)
- Umbilical artery partial pressure of carbon dioxide(24 hours)
- Umbilical artery partial pressure of oxygen(24 hours)
- Umbilical artery base excess(24 hours)
- Umbilical vein pH(24 hours)
- Umbilical vein partial pressure of oxygen(24 hours)