Influence of Variable Plasma Concentrations of Remifentanil on Burst Suppression (BS) Event Rate in Electroencephalographic (EEG) Recordings of Human Subjects Undergoing Total Intravenous General Anesthesia (TIVA) Under Propofol
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 发起方
- 入组人数
- 20
- 试验地点
- 2
- 主要终点
- Propofol estimated concentration by Marsh pharmacological model, which generates burst suppression
研究概览
简要总结
The goal of this clinical trial is to determine whether remifentanil has a facilitating effect on the generation of burst suppression by propofol in adult patients (18-60 years) candidates for elective surgery who require remifentanil and American Society of Anesthesiology (ASA) classification I or II. The main question it aims to answer are:
• To determine whether remifentanil has a facilitating effect on the generation of burst suppression by propofol.
Participants will undergo general anesthesia with remifentanil and propofol sequentially. After loss of consciousness, remifentanil will be adjusted to a medium or high concentration randomly and it will be determined at what concentration of propofol the burst suppressions are generated.
Then, the concentrations of propofol that generate burst suppression associated with either a medium or high concentration of remifentanil will be compared.
详细描述
Subjects will enter the ward, after which an 18 G intravenous cannula will be installed and will be monitored under the routinely applied ASA standard. Frontal EEG activity will be recorded using an anesthetic depth monitor and a baseline EEG will be recorded for 120 seconds with eyes closed. Subjects will then be preoxygenated. Once the oxygen concentration at the end of expiration reaches 90%, the administration of remifentanil will begin, under the Minto pharmacological model, to reach an effect site concentration of 7.5 ng/mL. Once the remifentanil concentration is reached, the infusion of propofol will begin at a rate of 15 mg/kg/h using Base Primea Orchestra, until loss of consciousness (LOC) is achieved. LOC will be defined as loss of response to verbal and tactile stimulation, which will be corroborated every 30 seconds. After this, the propofol infusion will be maintained at the concentration at which the LOC occurred, based on Marsh's pharmacological model, and rocuronium 0.6 mg/kg will be administered to facilitate orotracheal intubation.
Once the patient has been intubated, the remifentanil will be lowered to a concentration of 4 ng/mL and the surgery will continue. After 5 min after the LOC occurred, according to randomization, the concentration of remifentanil will remain at 4 ng/mL or increase to 7.5 ng/mL, and 10 min after the LOC occurred the propofol infusion rate will be changed to 15 mg/kg/h for 10 min. After this, the propofol concentration at which the LOC occurred will be returned and remifentanil will be maintained at 4 ng/mL. After 5 min after completing the previous step, remifentanil will be increased to 7.5 ng/mL or maintained at 4 ng/mL in the opposite way to what happened previously. After 10 min after completing the previous step, propofol will be dosed again at a fixed rate of 15 mg/kg/h for 10 min. Finally, after this time has elapsed, the concentration of propofol at which the LOC occurred will be returned and the remifentanil will be dosed according to the surgical requirements. Throughout the protocol, hemodynamics will be maintained with the usual management of drugs such as ephedrine in boluses or norepinephrine in continuous infusion.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Basic Science
- 盲法
- Single (Participant)
入排标准
- 年龄范围
- 18 Years 至 60 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •American Society of Anesthesiology I or II
- •Elective surgery of low or intermediate risk
排除标准
- •Neurological disease
- •Psychiatric disease
- •Use of psychoactive drugs or opioids
- •Altered basal state of consciousness
- •Allergy to propofol
- •Body mass index > 35 kg/m2
- •Pre-existing renal, cardiac and/or hepatic dysfunction
- •Patient's refusal to participate
研究组 & 干预措施
High dose
Propofol concentration which generate burst suppression at high dose of remifentanil
干预措施: High dose of remifentanil (Drug)
Medium dose
Propofol concentration which generate burst suppression at medium dose of remifentanil
干预措施: Medium dose of remifentanil (Drug)
结局指标
主要结局
Propofol estimated concentration by Marsh pharmacological model, which generates burst suppression
时间窗: During 10 minutes when propofol dosification is increased to 15 mg/kg/h
\[mcg/mL\]
次要结局
- Total ephedrine dose(During all protocol, 40 min)
- Bispectral index at burst suppression(During 10 minutes when propofol dosification is increased to 15 mg/kg/h)
- Propofol estimated concentration by Marsh pharmacological model, which generates loss of consciousness(Minutes, during anesthesia induction is performed)
- Maximal dose of norepinephrine(During all protocol, 40 min)
- Mean arterial pressure during burst suppression(During 10 minutes when propofol dosification is increased to 15 mg/kg/h)