Assessing the Potential for 'Covert Consciousness' in Unresponsive Patients
试验速览
- 阶段
- 不适用
- 入组人数
- 60
- 主要终点
- Asymmetry in feedback vs. feedforward network connectivity
研究概览
简要总结
In this study, the investigators explore anesthesia as a tool for providing further insight into the level of consciousness of individuals with a clinical diagnosis of unresponsive wakefulness syndrome (UWS), but who possess some neurophysiological signatures of conscious awareness. This group, who could potentially be conscious, will herein be referred to as the target population. Our goal is to assess whether or not neurological patterns of consciousness in the target population respond to anesthesia in a similar manner to neurologically compromised individuals with known consciousness (e.g. those in minimally conscious state (MCS). In healthy controls, propofol-induced unconsciousness results in an elimination of the mismatch negativity event-related brain potential (ERP) and a diminished directed connectivity. The investigators hypothesize that at doses well below those required for surgery, anesthesia will have similar effects on these neural patterns in neurologically compromised patients with the potential for conscious awareness, but will not affect these patterns in those who lack consciousness.
研究设计
- 研究类型
- Interventional
- 分配方式
- Non Randomized
- 干预模型
- Parallel
- 主要目的
- Basic Science
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 50 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Patients admitted to the intensive care unit at Hamilton General Hospital who:
- •Clinical status consistent with UWS (no responsiveness to commands)
- •Clinical status consistent with MCS (minimal response to at least one command)
- •Presence of an endotracheal tube (ETT) or a tracheostomy tube
- •Between 18 and 50 years of age
排除标准
- •• Elevated intracranial pressure (ICP)
- •Hepatic or renal failure
- •Hemodynamic instability
- •Active vasopressor therapy
- •Previous open-head injury
- •Previous intracranial pathology requiring neurosurgical interventions in the past 72 hours
- •Anticipated ICU stay < 24 hours
- •Documented allergy to propofol
- •Pregnancy
- •BMI > 35 kg/m2
- •Anyone who is deemed medically unsuitable for this study by the attending intensivist
- •Patients who are already in a medically-induced coma for intracranial hypertension or status epilepticus
研究组 & 干预措施
Control 1 (negative control)
Individuals with a diagnosis of UWS without neural markers of consciousness
干预措施: EEG recording (Device)
Control 2 (positive control)
Individuals with a diagnosis of MCS, who are behaviourally responsive and who present neural markers of consciousness
干预措施: EEG recording (Device)
Target Population
Individuals with a clinical diagnosis of UWS, but who possess some neurophysiological signatures of conscious awareness
干预措施: EEG recording (Device)
Target Population
Individuals with a clinical diagnosis of UWS, but who possess some neurophysiological signatures of conscious awareness
干预措施: Anesthetics, Intravenous (Drug)
结局指标
主要结局
Asymmetry in feedback vs. feedforward network connectivity
时间窗: 3 hours
EEG networks will be monitored pre, during and post anesthesia. Directed connectivity will be calculated using phase lag index (PLI) and symbolic transfer entropy (STE) between all combinations of EEG sensors. Average values of feedback connectivity (e.g. from the frontal regions to parietal and occipital regions) will be compared to average values of feedforward connectivity (e.g. from parietal and occipital regions to frontal regions). Positive asymmetry will be correlated to the presence of conscious awareness and negative asymmetry will be correlated to the absence of conscious awareness.
次要结局
- Presence of P300 and N400 event-related potentials(3 hours)
研究者
George Mashour
Bert N La De Professor of Anesthesiology Research
University of Michigan