Influence of Aging on Perioperative Methadone Dosing
试验速览
- 阶段
- 4 期
- 状态
- 已完成
- 入组人数
- 60
- 试验地点
- 1
- 主要终点
- Methadone plasmatic levels Measured by high pressure liquid chromatography
研究概览
简要总结
Increasingly, elderly patients undergo anesthesia and surgery. Methadone is a great opioid for perioperative pain management, however, to date there are no pharmacokinetic or pharmacodynamic studies that asses a methadone dose adjustment in the elderly patient. The present study is aimed to characterize the pharmacokinetic and pharmacodynamic age-related changes of methadone in the adult population and further to design reference dosing protocols for intraoperative methadone use according to patient age.
详细描述
The subjects will be recruited from adult patients who undergo elective laparoscopic abdominal surgery at UC Christus Clinical Hospital (Santiago, de Chile). Patients will be randomly divided into four groups according to the dose of intravenous methadone to be administered during anaesthetic induction.
BIS-guided and standard general anaesthesia will be administered with routine monitoring. Methadone will be administered once the patient is intubated and has hemodynamic stability. The only opioids that patients will receive will be remifentanil and methadone.
Upon admission to the Post-anesthesia care unit, the patient is given a Patient-Control Analgesia pump for intravenous administration of morphine. Clinic evaluations will be carried out periodically and blood samples for measurement of plasma methadone will be taken at different times. Samples will be analyzed using high-performance liquid chromatography spectrofluorometric method. The data obtained will be collected in a form within the REDCAP application, to subsequently generate an encrypted database. Groups will be compared regarding pain score, drugs used, opioid consumption, side effects, time of recovery, and patient satisfaction.
One, two and three-compartment linear models will be used to fit the plasma methadone concentration data over time. Models are parameterized in terms of elimination clearance, compartment distribution clearance, central volume and peripheral volume of distribution, as appropriate. The use of rescue morphine in the Post-anesthesia care unit will be used as a measure to relate the methadone dose (mg/kg) with the analgesic efficacy using an EMAX model. The data will be modelled using NONMEM VII. A proportional term will be used for variability between subjects. Additive and proportional terms will be used to characterize the unknown residual variability.
Sample size calculations were estimated using a simulation-based approach and previous work with a similar methodology. To achieve an adequate representation of all age groups 60 patients will be required, distributed among 20 patients between 18 and 40 years, 20 patients between 41 and 65 years, and 20 patients> 65 years.
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
- Double (Participant, Care Provider)
盲法说明
The masking will be generated on a research laboratory computer and will be stored in an encrypted file. This information will be known exclusively to a member of the research team present during the surgery, who will hand over preparing the corresponding medicine in a 20 cc syringe and hand it over to the treating anesthesiologist.
入排标准
- 年龄范围
- 18 Years 至 105 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Over 18 years.
- •ASA I, II or III.
- •Laparoscopic Abdominal Surgery.
排除标准
- •Use of opioids up to 5 days before surgery.
- •Acute Liver Failure or Chronic Liver Damage Child C.
- •Kidney damage with creatinine clearance estimated by Cockcroft-Gault formula <60 ml/min.
研究组 & 干预措施
Methadone 0
Induction will be performed with a bolus of propofol, continuous infusion of remifentanil, and rocuronium. Once the patient is intubated and has hemodynamic stability will be administered the placebo drug.
干预措施: Methadone Injectable Product (Drug)
Methadone 1
Induction will be performed with a bolus of propofol, continuous infusion of remifentanil, and rocuronium. Once the patient is intubated and has hemodynamic stability will be administered an intravenous methadone dose of 0.05 mg/kg.
干预措施: Methadone Injectable Product (Drug)
Methadone 2
Induction will be performed with a bolus of propofol, continuous infusion of remifentanil, and rocuronium. Once the patient is intubated and has hemodynamic stability will be administered an intravenous methadone dose of 0.1 mg/kg.
干预措施: Methadone Injectable Product (Drug)
Methadone 3
Induction will be performed with a bolus of propofol, continuous infusion of remifentanil, and rocuronium. Once the patient is intubated and has hemodynamic stability will be administered an intravenous methadone dose of 0.2 mg/kg.
干预措施: Methadone Injectable Product (Drug)
结局指标
主要结局
Methadone plasmatic levels Measured by high pressure liquid chromatography
时间窗: From the first dose up to 24 hours.
Five venous blood samples will be taken from each patient for methadone plasmatic level analysis. Patients will be randomly divided into two groups with different sample collection times. Group 1 at 0.05, 0.75, 1.5, 6, 18 hours post drug administration and Group 2 at 0.25, 1, 3, 12 and 24 hours.
次要结局
- Respiratory rate(Every 30 minutes. Since entering the recovery room up to 180 mins.)
- Heart Rate(Every 5 min. Since entering operating room up to end of anesthesia and leaving to recovery room. In average 2 hrs. Then, from the entrance to the recovery room every 30 minutes up to 180 minutes.)
- Intestinal transit recovery(Since the admission to the recovery room up to 2 hours.)
- Other opioids and pain management drugs used during recovery stay(Since the admission to the recovery room up to 2 hours.)
- Numeric Pain Rating Scale(Every 30 minutes. Since entering the recovery room up to 180 mins.)
- Sedation (Ramsay Scale)(Every 30 minutes. Since entering the recovery room up to 180 mins.)
- Hemodynamics(Every 5 min. Since entering operating room up to end of anesthesia and leaving to recovery room. In average 2 hrs. Then, from the entrance to the recovery room every 30 minutes up to 180 minutes.)
- Pulse oximetry(Every 5 min. Since entering operating room up to end of anesthesia and leaving to recovery room. In average 2 hrs. Then, from the entrance to the recovery room every 30 minutes up to 180 minutes.)
- BIS(Every 5 min. Since entering operating room up to end of anesthesia and leaving to recovery room. In average 2 hrs.)
- Nausea or vomiting(Every 30 minutes. Since entering the recovery room up to 180 mins.)
- Respiratory depression(Every 30 minutes. Since entering the recovery room up to 180 mins.)