Relationship Between Submental Tissue Oxygenation, Microvascular Reactivity, and Arterial Lactate During Major Surgical Procedures
试验速览
- 阶段
- 不适用
- 状态
- 尚未招募
- 发起方
- 入组人数
- 150
- 试验地点
- 1
- 主要终点
- Correlation between submental tissue oxygenation and arterial lactate levels
研究概览
简要总结
During major surgical procedures performed under general anesthesia, changes in blood flow and oxygen delivery to tissues may occur due to blood loss, hemodynamic fluctuations, and anesthesia-related physiological effects. These changes can lead to impaired tissue perfusion, which is commonly reflected by increased arterial lactate levels. However, lactate measurements are intermittent and may not detect early perfusion abnormalities.
This prospective observational study aims to investigate the relationship between submental tissue oxygenation measured by near-infrared spectroscopy (NIRS), microvascular reactivity assessed by the vascular occlusion test, and arterial lactate levels during major surgery. Adult patients undergoing major abdominal, neurosurgical, or orthopedic procedures will be monitored intraoperatively using non-invasive NIRS techniques, while arterial blood gas analyses will be performed as part of routine clinical care.
The study does not involve any changes to standard anesthesia or surgical management. All treatments and clinical decisions will be made by the responsible care team according to routine practice. By evaluating non-invasive indicators of tissue oxygenation and microvascular function, this study aims to improve the understanding of early intraoperative tissue perfusion changes and their association with metabolic markers.
详细描述
This prospective, single-center, observational cohort study is designed to evaluate the relationship between intraoperative submental tissue oxygenation, microvascular reactivity, and arterial lactate levels during major surgical procedures performed under general anesthesia.
Major surgery is defined as procedures associated with a substantial risk of blood loss and/or tissue perfusion impairment, requiring invasive arterial blood pressure monitoring and hourly arterial blood gas analysis. Eligible surgical categories include major abdominal, neurosurgical, and major orthopedic procedures. Adult patients aged 18 years and older who meet the inclusion criteria will be enrolled.
All anesthetic and surgical management will be conducted according to standard clinical practice. The study protocol will not influence clinical decision-making. Hemodynamic management, fluid therapy, blood product transfusion, and ventilatory settings will be determined solely by the responsible anesthesia and surgical teams.
Intraoperative tissue oxygenation will be continuously monitored using near-infrared spectroscopy (NIRS). A NIRS sensor will be placed on the submental region, just inferior to the mandibular border and near the midline, after appropriate skin preparation. The sensor will be secured to minimize ambient light interference and motion artifacts. Baseline submental tissue oxygenation will be defined as the values obtained during a hemodynamically stable period of at least five minutes following anesthesia induction, without active surgical stimulation or significant fluctuations in mean arterial pressure.
Submental NIRS measurements will be recorded at 15-minute intervals throughout the intraoperative period, and hourly average and minimum values will be documented. A NIRS desaturation event will be defined as a decrease of 10% or more from baseline tissue oxygenation lasting for at least three minutes.
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 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Adults aged 18 years and older
- •Scheduled for major surgical procedures under general anesthesia
- •Major surgery defined as procedures associated with a risk of significant blood loss and/or impaired tissue perfusion, requiring invasive arterial blood pressure monitoring and hourly arterial blood gas analysis
- •Planned intraoperative arterial catheter placement as part of routine clinical care
- •Ability to provide written informed consent
排除标准
- •Age younger than 18 years
- •Refusal or inability to provide informed consent
- •Absence of invasive arterial blood pressure monitoring
- •Known pregnancy
- •Severe peripheral vascular disease affecting upper extremities
- •Anatomical abnormalities or skin conditions preventing placement of NIRS sensors on the submental or thenar regions
- •Emergency surgery requiring immediate intervention
- •Preoperative severe metabolic acidosis (arterial pH < 7.20)
研究组 & 干预措施
Major Surgery
Adult patients aged 18 years and older undergoing major surgical procedures under general anesthesia will be included in this cohort. Major surgery is defined as surgical procedures associated with a risk of significant blood loss and/or impaired tissue perfusion, requiring invasive arterial blood pressure monitoring and hourly arterial blood gas analysis. Eligible procedures include major abdominal, neurosurgical, and major orthopedic surgeries.
All anesthetic and surgical management will be performed according to standard clinical practice. The study does not involve any experimental intervention or alteration of routine clinical care. Submental tissue oxygenation and microvascular reactivity will be monitored intraoperatively using non-invasive near-infrared spectroscopy techniques as part of observational data collection.
干预措施: No intervention. This is a prospective observational study. Near-infrared spectroscopy measurements are performed for monitoring purposes only and do not influence clinical management. (Other)
结局指标
主要结局
Correlation between submental tissue oxygenation and arterial lactate levels
时间窗: Intraoperatively, from anesthesia induction to the end of surgery
The strength and direction of the association between intraoperative submental tissue oxygenation measured by near-infrared spectroscopy and arterial lactate levels during major surgery.
次要结局
- Correlation between microvascular reactivity and arterial lactate levels(Intraoperatively, from anesthesia induction to the end of surgery)
- Intraoperative submental NIRS desaturation events(Intraoperatively, from anesthesia induction to the end of surgery)
- Relationship between submental tissue oxygenation and microvascular reactivity(Intraoperatively, from anesthesia induction to the end of surgery)
研究者
Gürcan Güler
Consultant Anesthesiologist and Intensivist
Bursa Sevket Yilmaz Training and Research Hospital