Effect of the Trendelenburg Position on Patient State Index and Frontal Cerebral Oxygenation: A Prospective Observational Study
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 发起方
- 入组人数
- 60
- 试验地点
- 1
- 主要终点
- Change in Patient State Index (ΔPSI) After Trendelenburg Position
研究概览
简要总结
The goal of this observational study is to evaluate whether the Trendelenburg position affects electroencephalography-based depth of anesthesia monitoring and cerebral oxygenation during general anesthesia.
The main questions it aims to answer are:
- Does the Trendelenburg position cause a change in the Patient State Index (PSI), an Electroensephalography (EEG)-derived indicator of anesthetic depth?
- Are changes in PSI associated with changes in frontal cerebral oxygen saturation (rSO₂) and hemodynamic parameters?
The study will include adult female patients undergoing elective laparoscopic gynecologic surgery under general anesthesia.
Participants will receive standard anesthesia and routine intraoperative monitoring. In addition to standard monitoring, Patient State Index (PSI) and frontal cerebral oxygen saturation (rSO₂) will be recorded using non-invasive sensors. No additional intervention will be performed for research purposes.
Physiological parameters including PSI, cerebral oxygen saturation, mean arterial pressure, heart rate, oxygen saturation, and end-tidal carbon dioxide will be recorded at predefined intraoperative time points before and after the Trendelenburg position.
The study aims to determine whether position-related physiological changes influence EEG-based anesthesia depth indices and to improve the interpretation of intraoperative brain monitoring.
详细描述
Electroencephalography (EEG)-based depth of anesthesia monitors are widely used to assess the hypnotic component of general anesthesia. The Patient State Index (PSI) is a processed EEG parameter derived from frontal EEG signals and provides a numerical estimate of anesthetic depth ranging from 0 to 100. Although these indices are primarily designed to reflect the pharmacologic effects of anesthetic agents, physiological factors that influence cerebral hemodynamics may also affect EEG-derived parameters.
The Trendelenburg position is frequently used during laparoscopic pelvic surgery to improve surgical exposure. This position can alter venous return, increase cerebral venous pressure, and influence intracranial dynamics. When combined with pneumoperitoneum, these physiological changes may modify cerebral blood flow and cerebral oxygenation. Such alterations may potentially influence EEG-based indices of anesthetic depth independently of anesthetic drug concentration.
Previous studies have demonstrated that body position can influence processed EEG indices such as the bispectral index (BIS), particularly in the beach-chair position. However, the response of the Patient State Index to the Trendelenburg position has not been clearly established.
This prospective observational study aims to evaluate whether the Trendelenburg position affects PSI values during general anesthesia and to investigate the relationship between PSI changes and cerebral oxygenation measured by near-infrared spectroscopy (NIRS).
Adult female patients undergoing elective laparoscopic hysterectomy under general anesthesia will be included. Standard intraoperative monitoring will be applied, including electrocardiography, non-invasive blood pressure, pulse oximetry, end-tidal carbon dioxide, and anesthetic gas monitoring. In addition, EEG-based depth of anesthesia monitoring will be performed using the PSI monitor (Masimo SedLine), and frontal cerebral oxygen saturation (rSO₂) will be measured using near-infrared spectroscopy sensors.
研究设计
- 研究类型
- Observational
- 观察模型
- Cohort
- 时间视角
- Prospective
入排标准
- 年龄范围
- 18 Years 至 65 Years（Adult, Older Adult）
- 性别
- Female
- 接受健康志愿者
- 否
入选标准
- •Female patients aged 18-65 years
- •American Society of Anesthesiologists (ASA) physical status I-III
- •Scheduled for elective laparoscopic hysterectomy under general anesthesia
- •Ability to provide written informed consent
排除标准
- •History of neurological disease (e.g., stroke, epilepsy)
- •Known cerebrovascular disease, glaucoma, or retinal disease
- •Severe cardiac or pulmonary disease
- •Contraindication to near-infrared spectroscopy sensor placement
- •Obesity (Body Mass Index > 35 kg/m²)
研究组 & 干预措施
Patients Undergoing Laparoscopic Hysterectomy in Trendelenburg Position
This cohort includes adult female patients undergoing elective laparoscopic hysterectomy under general anesthesia. All participants receive standard intraoperative monitoring as part of routine clinical care. In addition to routine monitoring, depth of anesthesia is assessed using the Patient State Index (PSI), and frontal cerebral oxygen saturation (rSO₂) is measured using near-infrared spectroscopy sensors.
Physiological parameters including PSI, cerebral oxygen saturation, mean arterial pressure, heart rate, oxygen saturation, and end-tidal carbon dioxide are recorded at predefined intraoperative time points before and after pneumoperitoneum and Trendelenburg positioning.
No intervention is performed for research purposes. Surgical positioning and anesthetic management follow routine clinical practice, and the study involves only the observational recording of physiological parameters.
结局指标
主要结局
Change in Patient State Index (ΔPSI) After Trendelenburg Position
时间窗: From Post-intubation (Supine) to Trendelenburg Positioning
The primary outcome is the change in Patient State Index (PSI), an Electroensephalography(EEG)-derived indicator of anesthetic depth, between the supine position after tracheal intubation and the early Trendelenburg position following pneumoperitoneum. PSI values will be recorded using the Masimo SedLine monitoring system. The analysis will evaluate whether Trendelenburg positioning is associated with a significant change in PSI independent of anesthetic drug concentration.
次要结局
- Change in Frontal Cerebral Oxygen Saturation (rSO₂)(Intraoperative period (recorded at predefined time points before and after Trendelenburg positioning))
- Mean Arterial Pressure Changes During Trendelenburg Position(Intraoperative period (recorded at predefined time points before and after Trendelenburg positioning))
- Heart Rate Changes During Trendelenburg Position(Intraoperative period (recorded at predefined time points before and after Trendelenburg positioning))
研究者
Ayça Taş Tuna
Prof.Dr.
Sakarya University