A Dose-response Study of Spinally Administered Ropivacaine Combined With a Fix Dose of Fentanyl for Elective Caesarean Section in Tall Parturients Under Combined Spinal-epidural Anaesthesia
试验速览
- 阶段
- 不适用
- 状态
- Enrolling By Invitation
- 发起方
- 入组人数
- 40
- 试验地点
- 2
- 主要终点
- MLAD of spinal ropivacaine administered to healthy tall parturients for cesarean delivery.
研究概览
简要总结
The main goal is to determine the optimum dose of ropivacaine, a local anaesthetic, that provides regional anaesthesia with no or minimum adverse effects (i.e. hypotension) when given spinally in healthy full term tall parturients scheduled to undergo caesarean section under combined spinal / epidural anaesthesia (CSEA). The participants' height threshold is based on a local anthropometric research, which included over 2000 people. According to the above research the investigators calculated the female height distribution and decided to include in the study those distributed in the upper quartile (75th to 99th percentile). The female height distribution of the upper quartile ranges from 167 to 184 cm.
Secondary objectives are adverse effects related to the anaesthetic technique (hypotension, discomfort, nausea, vomiting and pruritus), the speed of installation and the duration of the regional block (both sensory and motor), blood gas analysis of the newborn umbilical blood as well as newborn Apgar score and lastly the mothers' degree of satisfaction.
This is a prospective non randomized double-blinded trial in which a specific algorithm for the local anaesthetic dose will be adopted (up-down sequential allocation). A written informed consent will be required by all participants.
The perioperative management of all participants will follow standard clinical protocols.
The dose of ropivacaine for each parturient is determined by the response of the previous participant to a higher or lower dose according to the sequential distribution algorithm (up-down sequential allocation). Specifically, the dose of ropivacaine for each parturient (except for the first) will fluctuate by 0.375 mg depending on the success (decrease by 0.375 mg) or failure (increase by 0.375 mg) of the spinal anaesthesia of the previous parturient enrolled in the study. The local anaesthetic dose of the first participant will be determined by a short pilot study.
详细描述
The primary objective of this study is to determine the dose-response relationship of subarachnoid (spinal) administered ropivacaine to healthy tall parturients scheduled to undergo elective caesarean section under combined subarachnoid / epidural anaesthesia (CSEA) with co-administration of a fixed dose of fentanyl. The dose-response relationship will be described by determining ED50 (Effective Dose 50) and MLAD (Minimum Local Anaesthetic Dose).
The height threshold of the participants is based on the study "National Anthropometric Research: Effectiveness of Ergonomic Measurements and Applications." By G. Scroumbelos, University of Piraeus. Based on the female height distribution of the previously mentioned Anthropometric Research, we chose the upper quartile (75th to 99th percentile) as an inclusion criterion in our study, which ranges from 167 to 184 cm.
Secondary objectives are spinal induced hypotension, speed of installation and duration of sensory and motor blockade, blood gas analysis of the umbilical circulation of the newborn, Apgar score of the newborn, adverse effects related to the anaesthetic technique (discomfort, nausea, vomiting, pruritus) and the degree of maternal satisfaction.
This is a prospective non randomized double-blinded trial in which a specific algorithm for the local anaesthetic dose will be adopted (up-down sequential allocation, described below). A written informed consent will be required by all participants.
The perioperative management of the participants follows standard clinical protocols. Specifically, conventional non-invasive monitoring consisting of five lead electrocardiography, pulse oximetry and automatic oscillometric cuff blood pressure is used. A low-dose spinal via the needle-through-needle combined spinal-epidural (CSE) technique is employed. With the patient in the sedentary position, the O3-O4 intervertebral space is located, followed by skin antisepsis and topical lidocaine infiltration. The loss of resistance technique is used in order to locate the epidural space.
研究设计
- 研究类型
- Interventional
- 分配方式
- Na
- 干预模型
- Sequential
- 主要目的
- Treatment
- 盲法
- None
盲法说明
Two anaesthetists are required to conduct the study: a study supervisor who sets the dose of the local anaesthetic for the next participant according to the sequential distribution algorithm and performs the technique and an anaesthetist responsible for recording the study parameters and for the clinical management of the parturient, blinded to the administered dose.
入排标准
- 年龄范围
- 20 Years 至 40 Years（Adult）
- 性别
- Female
- 接受健康志愿者
- 是
入选标准
- •ASA status I - II (ASA; American Society of Anesthesiologists)
- •height: 167 to 184 cm
- •age: 20 to 40 years old
- •normal single pregnancy
- •full term pregnancy (> 37 weeks)
- •elective caesarean section.
排除标准
- •refusal of the parturient, inability to communicate
- •obesity (BMI> 35 Kg/m2)
- •baseline maternal heart rate less than 60 or above 130 bpm
- •high risk pregnancy (gestational hypertension, preeclampsia / eclampsia, gestational diabetes, multiple pregnancies)
- •known or suspected foetal pathology (intrauterine growth retardation, poly- or oligohydramnios)
- •history of clinically significant cardiovascular, pulmonary, hepatic, renal, neurological, psychiatric or metabolic disease
- •active labour
- •history of allergy in amidic anaesthetics or any of the drugs used in the trial
- •contraindications for regional technique such as coagulation disorders, inflammation of the lumbar region, systemic sepsis
- •dural puncture.
结局指标
主要结局
MLAD of spinal ropivacaine administered to healthy tall parturients for cesarean delivery.
时间窗: Two to three hours
Minimum Local Analgesic Dose (MLAD) of spinally administered ropivacaine (mg).
ED50 of spinal ropivacaine administered to healthy tall parturients for cesarean delivery.
时间窗: Two to three hours
Median Effective Dose (ED50) of spinally administered ropivacaine (mg).
次要结局
未报告次要终点
研究者
Paraskevi Matsota
Associate Professor of Anesthesiology, 2nd Department of Anaesthesiology, School of Medicine, University of Athens, "Attikon" Hospital, Athens, Greece.
Attikon Hospital