Respiratory Control and Prevention of Opioid-Induced Respiratory Depression After Surgery
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 10
- 试验地点
- 1
- 主要终点
- Opioid related respiratory depression (OIRD) frequency
研究概览
简要总结
The aim of this study is to provide data that will assess the role of ventilatory chemosensitivity (respiratory drive) in determining postoperative respiratory depression due to opioids. In a group of patients requiring surgery and admission to hospital, before surgery, ventilatory chemosensitivity will be assessed in the presence or absence of an infusion of remifentanil. Parameters will be correlated with ventilatory depression events after surgery. A secondary aim is to determine whether respiratory depression is more likely during specific phases of sleep.
详细描述
The study aims to test the following hypotheses:
Low respiratory drive is predictive of opioid-induced respiratory depression as defined by end-tidal PCO2 (PETCO2) >50 mmHg, ventilation <20% below baseline or pulse oximeter reading (SpO2) <90%.
Respiratory depression is more likely during certain sleep stages, specifically slow wave sleep.
Respiratory Drive. Before surgery each patient's hypercapnic ventilatory response under conditions of mild hypoxia and mild hyperoxia. Using this technique, the patient first voluntarily hyperventilates to a PETCO2 value of 20-25 mmHg, then undergoes a rebreathing test allowing the PCO2 to rise to 55-60 mmHg while end-tidal PO2 (PETO2) is maintained at 150 mmHg. The procedure is then repeated with PETO2 clamped at 50 mmHg. Parameters derived from this method include slopes of the ventilatory response during hyperoxia and hypoxia. The slope during mild hypoxia is felt to be an index of peripheral chemoreceptor function, while the hyperoxic slope is more indicative of central respiratory drive.
These two maneuvers will then be repeated during an infusion of the ultra-short acting opioid, remifentanil. Remifentanil will be administered to achieve a specified effect site concentration selected to produce a 30% decrease in ventilation using a standard pharmacokinetic model implemented on a widely-used shareware program (TIVATrainer, www.eurosaver.eu). Recovery from ventilatory depression occurs within 10 minutes of discontinuation of the infusion.
研究设计
- 研究类型
- Observational
- 观察模型
- Other
- 时间视角
- Prospective
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •18 years of age or older, undergoing major abdominal or urological surgery requiring at least one overnight hospital stay
排除标准
- •Pregnancy Adverse reaction to remifentanil Opioid-use within the past month Dependency on supplemental oxygen Brain injury in the past year Coronary artery disease Sickle cell disease.
结局指标
主要结局
Opioid related respiratory depression (OIRD) frequency
时间窗: From the arrival of the patient in the post anesthesia care unit until the first postoperative morning
A respiratory event is defined as one or more of the following: 1. Respiratory rate \<60% of baseline 2. Minute ventilation (MV) \<60% of predicted value based on body surface area (BSA). Predicted MV for men=4 x BSA, for women=3.5 x BSA 3. Pulse oximeter reading (SpO2) \<90% (breathing room air) or \<92% (breathing supplemental O2) 4. Transcutaneous PCO2 \>50 mmHg 5. Central or obstructive apnea/hypopnea detected by WatchPAT (Itamar Medical, Atlanta, GA) based on decrease in peripheral arterial tone amplitude, increase in heart rate and decrease in SpO2 ≥3% or snoring in the absence of body movement. Events must last 1 minute or more to be counted. Events occurring within one minute of each are combined as a single event.
次要结局
- Frequency of OIRD during specific sleep stages(From the arrival of the patient in the post anesthesia care unit until the first postoperative morning)